LP-109 add gstreamer library and video gadget

ground/gcs/src/libs/gstreamer/copydata.pro

@@ -0,0 +1,82 @@
+win32:gstreamer {
+
+    GST_BIN_DIR = $$system(pkg-config --variable=exec_prefix gstreamer-1.0)/bin
+    GST_PLUGINS_DIR = $$system(pkg-config --variable=pluginsdir gstreamer-1.0)
+
+    # gstreamer libraries
+    GST_LIBS = \
+        libgstreamer-1.0-0.dll
+
+    gstreamer_utilities:GST_LIBS += \
+        gst-inspect-1.0.exe \
+        gst-launch-1.0.exe
+
+    for(lib, GST_LIBS) {
+        addCopyFileTarget($${lib},$${GST_BIN_DIR},$${GCS_APP_PATH})
+        addCopyDependenciesTarget($${lib},$${GST_BIN_DIR},$${GCS_APP_PATH})
+    }
+
+    # gstreamer core
+    GST_PLUGINS = \
+        libgstcoreelements.dll
+
+    # gst-plugins-base
+    GST_PLUGINS += \
+        libgstapp.dll \
+        libgstaudiotestsrc.dll \
+        libgstpango.dll \
+        libgstplayback.dll \
+        libgsttcp.dll \
+        libgsttypefindfunctions.dll \
+        libgstvideoconvert.dll \
+        libgstvideorate.dll \
+        libgstvideoscale.dll \
+        libgstvideotestsrc.dll
+
+    # gst-plugins-good
+    GST_PLUGINS += \
+        libgstautodetect.dll \
+        libgstavi.dll \
+        libgstdeinterlace.dll \
+        libgstdirectsoundsink.dll \
+        libgstimagefreeze.dll \
+        libgstjpeg.dll \
+        libgstrawparse.dll \
+        libgstrtp.dll \
+        libgstrtpmanager.dll \
+        libgstrtsp.dll \
+        libgstudp.dll \
+        libgstvideomixer.dll
+
+    # gst-plugins-bad
+    GST_PLUGINS += \
+        libgstaudiovisualizers.dll \
+        libgstautoconvert.dll \
+        libgstcompositor.dll \
+        libgstd3dvideosink.dll \
+        libgstdebugutilsbad.dll \
+        libgstdirectsoundsrc.dll \
+        libgstinter.dll \
+        libgstmpegpsdemux.dll \
+        libgstmpegpsmux.dll \
+        libgstmpegtsdemux.dll \
+        libgstmpegtsmux.dll \
+        libgstvideoparsersbad.dll \
+        libgstwinks.dll \
+        libgstwinscreencap.dll
+
+    # gst-plugins-ugly
+    GST_PLUGINS += \
+        libgstmpeg2dec.dll \
+        libgstx264.dll
+
+    # gst-libav
+    GST_PLUGINS += \
+        libgstlibav.dll
+
+    for(lib, GST_PLUGINS) {
+        addCopyFileTarget($${lib},$${GST_PLUGINS_DIR},$${GCS_LIBRARY_PATH}/gstreamer-1.0)
+        addCopyDependenciesTarget($${lib},$${GST_PLUGINS_DIR},$${GCS_APP_PATH})
+    }
+
+}

ground/gcs/src/libs/gstreamer/devicemonitor.cpp

@@ -0,0 +1,136 @@
+/**
+ ******************************************************************************
+ *
+ * @file       devicemonitor.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "devicemonitor.h"
+
+#include "gst_util.h"
+
+#include <gst/gst.h>
+
+#include <QDebug>
+
+static GstBusSyncReply my_bus_sync_func(GstBus *bus, GstMessage *message, gpointer user_data)
+{
+    Q_UNUSED(bus)
+
+    DeviceMonitor * dm;
+    GstDevice *device;
+    gchar *name;
+
+    switch (GST_MESSAGE_TYPE(message)) {
+    case GST_MESSAGE_DEVICE_ADDED:
+        gst_message_parse_device_added(message, &device);
+        name = gst_device_get_display_name(device);
+
+        dm   = (DeviceMonitor *)user_data;
+        QMetaObject::invokeMethod(dm, "device_added", Qt::QueuedConnection,
+                                  Q_ARG(QString, QString(name)));
+
+        g_free(name);
+        break;
+    case GST_MESSAGE_DEVICE_REMOVED:
+        gst_message_parse_device_removed(message, &device);
+        name = gst_device_get_display_name(device);
+
+        dm   = (DeviceMonitor *)user_data;
+        QMetaObject::invokeMethod(dm, "device_removed", Qt::QueuedConnection,
+                                  Q_ARG(QString, QString(name)));
+
+        g_free(name);
+        break;
+    default:
+        break;
+    }
+
+    // no need to pass it to the async queue, there is none...
+    return GST_BUS_DROP;
+}
+
+DeviceMonitor::DeviceMonitor(QObject *parent) : QObject(parent)
+{
+    // initialize gstreamer
+    gst::init(NULL, NULL);
+
+    monitor = gst_device_monitor_new();
+
+    GstBus *bus = gst_device_monitor_get_bus(monitor);
+    gst_bus_set_sync_handler(bus, (GstBusSyncHandler)my_bus_sync_func, this, NULL);
+    gst_object_unref(bus);
+
+    GstCaps *caps = NULL; // gst_caps_new_empty_simple("video/x-raw");
+    const gchar *classes = "Video/Source";
+    gst_device_monitor_add_filter(monitor, classes, caps);
+    if (caps) {
+        gst_caps_unref(caps);
+    }
+
+    if (!gst_device_monitor_start(monitor)) {
+        qWarning() << "Failed to start device monitor";
+    }
+}
+
+DeviceMonitor::~DeviceMonitor()
+{
+    gst_device_monitor_stop(monitor);
+    gst_object_unref(monitor);
+}
+
+QList<Device> DeviceMonitor::devices() const
+{
+    QList<Device> devices;
+
+    GList *list = gst_device_monitor_get_devices(monitor);
+    while (list != NULL) {
+        gchar *name;
+        gchar *device_class;
+
+        GstDevice *device = (GstDevice *)list->data;
+        name = gst_device_get_display_name(device);
+        device_class = gst_device_get_device_class(device);
+
+        devices << Device(name, device_class);
+
+        g_free(name);
+        g_free(device_class);
+
+        gst_object_unref(device);
+        list = g_list_remove_link(list, list);
+    }
+
+    return devices;
+}
+
+void DeviceMonitor::device_added(QString name)
+{
+    // qDebug() << "**** ADDED:" << name;
+    emit deviceAdded(name);
+}
+
+void DeviceMonitor::device_removed(QString name)
+{
+    // qDebug() << "**** REMOVED:" << name;
+    emit deviceRemoved(name);
+}

ground/gcs/src/libs/gstreamer/devicemonitor.h

@@ -0,0 +1,73 @@
+/**
+ ******************************************************************************
+ *
+ * @file       devicemonitor.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef DEVICEMONITOR_H_
+#define DEVICEMONITOR_H_
+
+#include "gst_global.h"
+
+#include <QObject>
+
+typedef struct _GstDeviceMonitor GstDeviceMonitor;
+
+class Device {
+public:
+    Device(QString displayName, QString deviceClass) : m_displayName(displayName), m_deviceClass(deviceClass)
+    {}
+    QString displayName() const
+    {
+        return m_displayName;
+    }
+    QString deviceClass() const
+    {
+        return m_deviceClass;
+    }
+private:
+    QString m_displayName;
+    QString m_deviceClass;
+};
+
+class GST_LIB_EXPORT DeviceMonitor : public QObject {
+    Q_OBJECT
+public:
+    DeviceMonitor(QObject *parent = NULL);
+    virtual ~DeviceMonitor();
+
+    QList<Device> devices() const;
+
+signals:
+    void deviceAdded(QString name);
+    void deviceRemoved(QString name);
+
+private:
+    GstDeviceMonitor *monitor;
+
+private slots:
+    void device_added(QString name);
+    void device_removed(QString name);
+};
+
+#endif /* DEVICEMONITOR_H_ */

ground/gcs/src/libs/gstreamer/gst_global.h

@@ -0,0 +1,38 @@
+/**
+ ******************************************************************************
+ *
+ * @file       gst_global.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef GST_GLOBAL_H
+#define GST_GLOBAL_H
+
+#include <QtCore/qglobal.h>
+
+#if defined(GST_LIB_LIBRARY)
+#  define GST_LIB_EXPORT Q_DECL_EXPORT
+#else
+#  define GST_LIB_EXPORT Q_DECL_IMPORT
+#endif
+
+#endif // GST_GLOBAL_H

ground/gcs/src/libs/gstreamer/gst_util.cpp

@@ -0,0 +1,125 @@
+/**
+ ******************************************************************************
+ *
+ * @file       gst_util.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "gst_util.h"
+
+#include <gst/gst.h>
+
+#ifdef USE_OPENCV
+#include "plugins/cameracalibration/gstcameracalibration.h"
+#include "plugins/cameracalibration/gstcameraundistort.h"
+#endif
+
+#include "utils/pathutils.h"
+
+#include <QDebug>
+
+static bool initialized = false;
+
+gboolean gst_plugin_librepilot_register(GstPlugin *plugin)
+{
+#ifdef USE_OPENCV
+    if (!gst_camera_calibration_plugin_init(plugin)) {
+        return FALSE;
+    }
+    if (!gst_camera_undistort_plugin_init(plugin)) {
+        return FALSE;
+    }
+#else
+    Q_UNUSED(plugin)
+#endif
+    return TRUE;
+}
+
+void gst_plugin_librepilot_register()
+{
+    gst_plugin_register_static(GST_VERSION_MAJOR, GST_VERSION_MINOR, "librepilot",
+                               "LibrePilot plugin", gst_plugin_librepilot_register, "1.10.0", "GPL",
+                               "librepilot", "LibrePilot", "http://librepilot.org/");
+}
+
+// see http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gst-running.html
+void gst::init(int *argc, char * *argv[])
+{
+    // TODO Not thread safe. Does it need to be?
+    if (initialized) {
+        return;
+    }
+    initialized = true;
+
+    // qputenv("GST_DEBUG", "3");
+    // qputenv("GST_DEBUG", "3,rtspsrc:6,udpsrc:6");
+    // qputenv("GST_DEBUG", "3,bin:6");
+    // qputenv("GST_DEBUG", "3,rtpjitterbuffer:6");
+    // qputenv("GST_DEBUG_FILE", "gst.log");
+    // qputenv("GST_DEBUG_DUMP_DOT_DIR", ".");
+
+
+#ifdef Q_OS_WIN
+    qputenv("GST_PLUGIN_PATH_1_0", (Utils::GetLibraryPath() + "gstreamer-1.0").toLatin1());
+#endif
+
+    qDebug() << "gstreamer - initializing";
+    GError *error = NULL;
+    if (!gst_init_check(argc, argv, &error)) {
+        qCritical() << "failed to initialize gstreamer";
+        return;
+    }
+
+    qDebug() << "gstreamer - version:" << gst_version_string();
+    qDebug() << "gstreamer - plugin system path:" << qgetenv("GST_PLUGIN_SYSTEM_PATH_1_0");
+    qDebug() << "gstreamer - plugin path:" << qgetenv("GST_PLUGIN_PATH_1_0");
+
+    qDebug() << "gstreamer - registering plugins";
+    // GST_PLUGIN_STATIC_REGISTER(librepilot);
+    gst_plugin_librepilot_register();
+
+#ifdef USE_OPENCV
+    // see http://stackoverflow.com/questions/32477403/how-to-know-if-sse2-is-activated-in-opencv
+    // see http://answers.opencv.org/question/696/how-to-enable-vectorization-in-opencv/
+    if (!cv::checkHardwareSupport(CV_CPU_SSE)) {
+        qWarning() << "SSE not supported";
+    }
+    if (!cv::checkHardwareSupport(CV_CPU_SSE2)) {
+        qWarning() << "SSE2 not supported";
+    }
+    if (!cv::checkHardwareSupport(CV_CPU_SSE3)) {
+        qWarning() << "SSE3 not supported";
+    }
+    qDebug() << "MMX    :" << cv::checkHardwareSupport(CV_CPU_MMX);
+    qDebug() << "SSE    :" << cv::checkHardwareSupport(CV_CPU_SSE);
+    qDebug() << "SSE2   :" << cv::checkHardwareSupport(CV_CPU_SSE2);
+    qDebug() << "SSE3   :" << cv::checkHardwareSupport(CV_CPU_SSE3);
+    qDebug() << "SSE4_1 :" << cv::checkHardwareSupport(CV_CPU_SSE4_1);
+    qDebug() << "SSE4_2 :" << cv::checkHardwareSupport(CV_CPU_SSE4_2);
+#endif
+}
+
+QString gst::version(void)
+{
+    init(NULL, NULL);
+    return QString(gst_version_string());
+}

ground/gcs/src/libs/gstreamer/gst_util.h

@@ -0,0 +1,39 @@
+/**
+ ******************************************************************************
+ *
+ * @file       gst_util.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef GST_UTIL_H
+#define GST_UTIL_H
+
+#include "gst_global.h"
+
+#include <QString>
+
+namespace gst {
+GST_LIB_EXPORT void init(int *argc, char * *argv[]);
+GST_LIB_EXPORT QString version();
+}
+
+#endif // GST_UTIL_H

ground/gcs/src/libs/gstreamer/gstreamer.pri

@@ -0,0 +1,3 @@
+LIBS *= -l$$qtLibraryName(GCSGStreamer)
+
+INCLUDEPATH += $$GCS_SOURCE_TREE/src/libs/gstreamer

ground/gcs/src/libs/gstreamer/gstreamer.pro

@@ -0,0 +1,29 @@
+TEMPLATE = lib
+TARGET = GCSGStreamer
+DEFINES += GST_LIB_LIBRARY
+
+QT += widgets
+
+include(../../library.pri)
+include(../utils/utils.pri)
+
+include(gstreamer_dependencies.pri)
+
+gstreamer_plugins:include(plugins/plugins.pro)
+
+HEADERS += \
+    gst_global.h \
+    gst_util.h \
+    devicemonitor.h \
+    pipeline.h \
+    pipelineevent.h \
+    overlay.h \
+    videowidget.h
+
+SOURCES += \
+    gst_util.cpp \
+    devicemonitor.cpp \
+    pipeline.cpp \
+    videowidget.cpp
+
+equals(copydata, 1):include(copydata.pro)

ground/gcs/src/libs/gstreamer/gstreamer_dependencies.pri

@@ -0,0 +1,9 @@
+DEFINES += USE_GSTREAMER
+opencv:DEFINES += USE_OPENCV
+
+linux|win32 {
+    CONFIG += link_pkgconfig
+    PKGCONFIG += glib-2.0 gobject-2.0
+    PKGCONFIG += gstreamer-1.0 gstreamer-video-1.0
+    opencv:PKGCONFIG += opencv
+}

ground/gcs/src/libs/gstreamer/notes.txt

@@ -0,0 +1,155 @@
+
+Tips:
+- Measuring video latency : display time on video + film video output -> the time between two frames is the latency
+
+Limitations:
+- It is not possible to view a web cam in two different gadgets (same is *not* true for DirectSound sources)
+  but it is not really an issue, as it possible to tee a video source in the pipeline itself
+
+ Issues:
+ - bad: libgstchromaprint - libchromaprint needs avcodec-56 (vs 57) and avutil-54 (vs 55)
+ - bad: libgstfragmented - needs libnettle-6-1 (vs 6-2) - was renamed to hls
+ - bad: libgstx265  - needs rebuild
+ - need to rebuild libgstpluginsbad and libchromaprint
+
+ Todo:
+ - should use openglvideosink for PFD
+ - save config as QR code and ...
+ - split cameraconfiguration -> cameraundistort
+ - exclude gst plugins from uncrustify
+ - fix crash on unsupported formats:
+ - undistort should be passthrough when not enabled
+
+
+
+gst-launch-1.0.exe -v -m autovideosrc ! video/x-raw,format=BGRA,width=800,height=600 ! videoconvert ! queue ! x264enc pass=qual quantizer=20 tune=zerolatency ! rtph264pay ! udpsink host=127.0.0.1 port=5000
+gst-launch-1.0.exe -v -m udpsrc port=5000 ! "application/x-rtp, payload=127" ! rtph264depay ! decodebin ! videoconvert ! timeoverlay ! autovideosink
+
+
+autovideosrc ! videoconvert ! queue ! x264enc pass=qual quantizer=20 tune=zerolatency ! rtph264pay ! udpsink host=127.0.0.1 port=5000
+autovideosrc ! queue ! videoscale ! video/x-raw,width=320,height=200 ! videoconvert ! x264enc tune=zerolatency ! rtph264pay ! udpsink host=127.0.0.1 port=5000
+autovideosrc ! queue ! videoscale ! videorate ! video/x-raw,width=320,height=240,frame-rate=30/1 ! videoconvert ! x264enc tune=zerolatency ! rtph264pay ! udpsink host=127.0.0.1 port=5000
+
+udpsrc port=5000 ! application/x-rtp,payload=96,clock-rate=90000 ! rtpjitterbuffer latency=30 ! rtph264depay ! decodebin ! videoconvert ! timeoverlay ! fpsdisplaysink
+
+RTSP
+server : ./test-launch.exe "( videotestsrc ! x264enc tune=zerolatency ! rtph264pay name=pay0 pt=96 )"
+client : gst-launch-1.0.exe -v -m rtspsrc location=rtsp://127.0.0.1:8554/test latency=30 ! decodebin ! timeoverlay ! autovideosink
+
+Qt:
+	Line 250058: 0:02:34.185436460  5988    d5a0480 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:02:34.081238026, base 0:00:00.050268441, recv_diff 0:02:34.030969585, slope 8
+	Line 250059: 0:02:34.185499451  5988    d5a0480 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:642:calculate_skew: delta -2352638, new min: -2417925
+	Line 250060: 0:02:34.185552513  5988    d5a0480 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -2398275, out 0:02:34.081192389
+
+RTP
+server : gst-launch-1.0.exe -v -m videotestsrc ! x264enc tune=zerolatency ! rtph264pay ! udpsink host=127.0.0.1 port=5000
+client : gst-launch-1.0.exe -v -m udpsrc port=5000 ! application/x-rtp,payload=96,clock-rate=90000 ! rtpjitterbuffer ! rtph264depay ! decodebin ! videoconvert ! timeoverlay ! autovideosink 
+
+WIFI CAM RTSP
+client : gst-launch-1.0.exe -v -m rtspsrc location=rtsp://192.168.42.1/AmbaStreamTest latency=30 ! decodebin ! timeoverlay ! autovideosink
+Qt:
+	Line 14594: 0:00:28.489562097  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:19.812089201, base 0:00:04.161093352, recv_diff 0:00:15.650995849, slope 7
+	Line 14595: 0:00:28.489625088  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:642:calculate_skew: delta 2029182, new min: -2061750
+	Line 14596: 0:00:28.489677219  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -2246751, out 0:00:19.807813268
+	Line 14612: 0:00:28.527222391  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:19.849735841, base 0:00:04.161093352, recv_diff 0:00:15.688642489, slope 7
+	Line 14613: 0:00:28.527285692  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:642:calculate_skew: delta 6309156, new min: -2061750
+	Line 14614: 0:00:28.527339685  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -2245270, out 0:00:19.841181415
+	Line 14630: 0:00:28.564027806  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:19.886522948, base 0:00:04.161093352, recv_diff 0:00:15.725429596, slope 7
+	Line 14631: 0:00:28.564091728  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:642:calculate_skew: delta 9729596, new min: -2061750
+	Line 14632: 0:00:28.564145410  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -2243801, out 0:00:19.874549551
+	Line 14654: 0:00:31.712747597  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.035042595, base 0:00:04.161093352, recv_diff 0:00:18.873949243, slope 6
+	Line 14655: 0:00:31.712811519  9388    d5b9518 WARN         rtpjitterbuffer rtpjitterbuffer.c:570:calculate_skew: delta - skew: 0:00:03.127126377 too big, reset skew
+	Line 14656: 0:00:31.712867063  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 0, delta 0
+	Line 14657: 0:00:31.712919194  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew 0, out 0:00:23.035042595
+	Line 14759: 0:00:31.720619622  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.043193270, base 0:00:23.035042595, recv_diff 0:00:00.008150675, slope 32
+	Line 14760: 0:00:31.720681061  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 1, delta -25215991
+	Line 14761: 0:00:31.720734123  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -2521, out 0:00:23.068406740
+	Line 14774: 0:00:31.721641753  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.044219745, base 0:00:23.035042595, recv_diff 0:00:00.009177150, slope 58
+	Line 14775: 0:00:31.721703813  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 2, delta -57556183
+	Line 14776: 0:00:31.721755633  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -54319, out 0:00:23.101721609
+	Line 14789: 0:00:31.722667608  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.045249324, base 0:00:23.035042595, recv_diff 0:00:00.010206729, slope 78
+	Line 14790: 0:00:31.722730288  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 3, delta -89893271
+	Line 14791: 0:00:31.722782729  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -278916, out 0:00:23.134863679
+	Line 14804: 0:00:31.723697497  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.046273007, base 0:00:23.035042595, recv_diff 0:00:00.011230412, slope 95
+	Line 14805: 0:00:31.723759557  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 4, delta -122236254
+	Line 14806: 0:00:31.723811687  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -717962, out 0:00:23.167791299
+	[...]
+	Line 14864: 0:00:31.727785401  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.050366186, base 0:00:23.035042595, recv_diff 0:00:00.015323591, slope 139
+	Line 14865: 0:00:31.727851185  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 8, delta -251609742
+	Line 14866: 0:00:31.727903626  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -10312755, out 0:00:23.291663173
+	Line 14964: 0:00:31.732567449  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.055371651, base 0:00:23.035042595, recv_diff 0:00:00.020329056, slope 118
+	Line 14965: 0:00:31.732595996  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 9, delta -279970944
+	Line 14966: 0:00:31.732620200  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -16380064, out 0:00:23.318962531
+	[...]
+	Line 15293: 0:00:31.746166387  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.068966555, base 0:00:23.035042595, recv_diff 0:00:00.033923960, slope 180
+	Line 15294: 0:00:31.746194935  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 23, delta -733509373
+	Line 15295: 0:00:31.746218828  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -430859680, out 0:00:23.371616248
+	Line 15310: 0:00:31.746791023  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:563:calculate_skew: time 0:00:23.069478242, base 0:00:23.035042595, recv_diff 0:00:00.034435647, slope 186
+	Line 15311: 0:00:31.746820812  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:580:calculate_skew: filling 24, delta -766364353
+	Line 15312: 0:00:31.746845636  9388    d5b9518 DEBUG        rtpjitterbuffer rtpjitterbuffer.c:664:calculate_skew: skew -484540427, out 0:00:23.351302168
+	[...]
+
+
+The high skew values can also be seen when using gst-launch but no pauses...
+
+The pause duration is variable (~4s) but the pause is always on the beat every 10s (If the first pause is at 9s, then the next will be at 19s, then 29s, etc...).
+
+Is it possible to disable the rtpjitterbuffer ?
+
+Qos: element autovideosink1-actual-sink-d3dvideo sent qos event: live: 1; running time: 30719164049; stream time: 26558070697; timestamp: 30719164049; duration: 33366666 jitter: 3029708354; proportion: 0.15581; quality: 1000000; format: ; processed: 609; dropped: 2;
+
+
+Wifi stall
+
+0:04:39.600000124  8296    ee56ba0 LOG                   udpsrc gstudpsrc.c:882:gst_udpsrc_create:<udpsrc0> doing select, timeout -1
+0:04:39.628925951  8296    ee56b10 DEBUG                rtspsrc gstrtspsrc.c:2260:gst_rtspsrc_handle_src_event:<rtspsrc0> pad rtspsrc0:recv_rtp_src_0_275680090_96 received event qos
+0:04:39.661793203  8296    ee56b10 DEBUG                rtspsrc gstrtspsrc.c:2260:gst_rtspsrc_handle_src_event:<rtspsrc0> pad rtspsrc0:recv_rtp_src_0_275680090_96 received event qos
+0:04:42.688912775  8296    ee56ba0 LOG                   udpsrc gstudpsrc.c:1014:gst_udpsrc_create:<udpsrc0> read packet of 26 bytes
+0:04:42.689055513  8296    ee56ba0 WARN         rtpjitterbuffer rtpjitterbuffer.c:570:calculate_skew: delta - skew: 0:00:03.058485393 too big, reset skew
+
+
+
+Simply instantiating a QNetworkAccessManager will cause the active wifi network connection to stall for 3 seconds every 10s.
+
+This affects, not just the Qt app, but also all other processes using the wifi connection.
+
+From what I have gathered this is due to bearer management polling all interfaces every 10s (can be changed with the QT_BEARER_POLL_TIMEOUT environment variable).
+On windows polling the wifi interface will trigger an ssid scan. That scan will stall the active connection. This might not happen with all wifi devices but does with mine.
+In my case, setting QT_BEARER_POLL_TIMEOUT to less than 4 seconds results in a DoS ;)
+
+https://msdn.microsoft.com/fr-fr/library/windows/desktop/ms706783(v=vs.85).aspx
+quote: "Since it becomes more difficult for a wireless interface to send and receive data packets while a scan is occurring, the WlanScan function may increase latency until the network scan is complete."
+
+
+# transmit gstreamer buffers over network
+tcpserversrc host=0.0.0.0 port=50002 ! gdpdepay ! autovideoconvert ! autovideosink
+v4l2src num-buffers=1 ! gdppay ! tcpclientsink host=0.0.0.0 port=50002
+
+# play a rtsp stream
+rtspsrc location=rtsp://192.168.42.1/AmbaStreamTest latency=30 ! decodebin ! timeoverlay ! autovideosink
+
+# play video and sound 
+ksvideosrc ! queue ! mix.
+directsoundsrc ! tee name=split ! queue ! directsoundsink
+split. ! queue ! wavescope ! queue ! mix.
+videomixer name=mix ! queue ! timeoverlay ! autovideosink
+
+ksvideosrc ! queue ! timeoverlay ! autovideosink
+directsoundsrc ! queue ! directsoundsink
+
+directsoundsrc ! tee name=split ! queue ! directsoundsink
+split. ! queue ! wavescope ! autovideosink
+
+filesrc location=C:/Users/Utilisateur/Desktop/hst_2.mpg ! decodebin ! autovideosink
+
+dx9screencapsrc  ! queue ! videoconvert ! x264enc bitrate=498 ! avimux ! filesink location=capture.avi
+
+
+compositor name=mixer background=black sink_0::offset=0 sink_1::offset=0 ! videoconvert ! autovideosink
+ksvideosrc device_index=0 ! decodebin ! identity drop-probability=0 ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=10000000000 ! mixer.
+udpsrc port=9000 ! identity drop-probability=0 dump=false ! <something> ! video/x-raw, width=640, height=480 ! videorate drop-only=true ! video/x-raw, framerate=10/1 ! queue max-size-buffers=0 max-size-bytes=0 max-size-time=10000000000 ! mixer.
+
+
+compositor name=mixer sink_1::ypos=50 ! videoconvert ! timeoverlay shaded-background=true auto-resize=false ! autovideosink sync=true
+ksvideosrc ! video/x-raw ! decodebin ! queue ! mixer.
+udpsrc port=9000 ! identity dump=false ! textrender halignment=left line-alignment=left ! video/x-raw, width=320, height=120 ! videorate drop-only=true ! video/x-raw, framerate=10/1 ! queue ! mixer.

ground/gcs/src/libs/gstreamer/overlay.h

@@ -0,0 +1,39 @@
+/**
+ ******************************************************************************
+ *
+ * @file       overlay.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef OVERLAY_H_
+#define OVERLAY_H_
+
+class Overlay {
+public:
+    Overlay()
+    {}
+    virtual ~Overlay()
+    {}
+    virtual void expose() = 0;
+};
+
+#endif /* OVERLAY_H_ */

ground/gcs/src/libs/gstreamer/pipeline.cpp

@@ -0,0 +1,38 @@
+/**
+ ******************************************************************************
+ *
+ * @file       pipeline.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "pipeline.h"
+
+#include "gst_util.h"
+
+Pipeline::Pipeline()
+{
+    // initialize gstreamer
+    gst::init(NULL, NULL);
+}
+
+Pipeline::~Pipeline()
+{}

ground/gcs/src/libs/gstreamer/pipeline.h

@@ -0,0 +1,41 @@
+/**
+ ******************************************************************************
+ *
+ * @file       pipeline.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef PIPELINE_H_
+#define PIPELINE_H_
+
+#include "gst_global.h"
+
+class GST_LIB_EXPORT Pipeline {
+public:
+    enum State {
+        VoidPending, Null, Ready, Paused, Playing
+    };
+    Pipeline();
+    virtual ~Pipeline();
+};
+
+#endif /* PIPELINE_H_ */

ground/gcs/src/libs/gstreamer/pipelineevent.h

@@ -0,0 +1,413 @@
+/**
+ ******************************************************************************
+ *
+ * @file       pipelineevent.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef PIPELINEEVENT_H_
+#define PIPELINEEVENT_H_
+
+#include <QEvent>
+#include <QString>
+
+#include "pipeline.h"
+#include "overlay.h"
+
+class PipelineEvent : public QEvent {
+public:
+    // event types
+    static const QEvent::Type PrepareWindowId;
+    static const QEvent::Type StateChange;
+    static const QEvent::Type StreamStatus;
+    static const QEvent::Type NewClock;
+    static const QEvent::Type ClockProvide;
+    static const QEvent::Type ClockLost;
+    static const QEvent::Type Progress;
+    static const QEvent::Type Latency;
+    static const QEvent::Type Qos;
+    static const QEvent::Type Eos;
+    static const QEvent::Type Error;
+    static const QEvent::Type Warning;
+    static const QEvent::Type Info;
+
+    PipelineEvent(QEvent::Type type, QString src) :
+        QEvent(type), src(src)
+    {}
+    virtual ~PipelineEvent()
+    {}
+public:
+    QString src;
+};
+
+const QEvent::Type PipelineEvent::PrepareWindowId = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::StateChange     = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::StreamStatus    = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::NewClock = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::ClockProvide    = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::ClockLost = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Progress  = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Latency   = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Qos = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Eos = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Error     = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Warning   = static_cast<QEvent::Type>(QEvent::registerEventType());
+const QEvent::Type PipelineEvent::Info = static_cast<QEvent::Type>(QEvent::registerEventType());
+
+class PrepareWindowIdEvent : public PipelineEvent {
+public:
+    PrepareWindowIdEvent(QString src, Overlay *overlay) :
+        PipelineEvent(PrepareWindowId, src), overlay(overlay)
+    {}
+    Overlay *getOverlay()
+    {
+        return overlay;
+    }
+    static QEvent::Type type()
+    {
+        return PrepareWindowId;
+    }
+private:
+    Overlay *overlay;
+};
+
+class StateChangedEvent : public PipelineEvent {
+public:
+    StateChangedEvent(QString src, Pipeline::State oldState, Pipeline::State newState, Pipeline::State pendingState) :
+        PipelineEvent(StateChange, src), oldState(oldState), newState(newState), pendingState(pendingState)
+    {}
+    static QEvent::Type type()
+    {
+        return StateChange;
+    }
+    Pipeline::State getOldState()
+    {
+        return oldState;
+    }
+    Pipeline::State getNewState()
+    {
+        return newState;
+    }
+    Pipeline::State getPendingState()
+    {
+        return pendingState;
+    }
+    static const char *stateName(Pipeline::State state)
+    {
+        switch (state) {
+        case Pipeline::VoidPending:
+            return "VoidPending";
+
+        case Pipeline::Null:
+            return "Null";
+
+        case Pipeline::Ready:
+            return "Ready";
+
+        case Pipeline::Paused:
+            return "Paused";
+
+        case Pipeline::Playing:
+            return "Playing";
+        }
+        return "<unknown>";
+    }
+private:
+    Pipeline::State oldState;
+    Pipeline::State newState;
+    Pipeline::State pendingState;
+};
+
+class StreamStatusEvent : public PipelineEvent {
+public:
+    enum StreamStatusType {
+        Create, Enter, Leave, Destroy, Start, Pause, Stop, Null
+    };
+    StreamStatusEvent(QString src, StreamStatusType status, QString owner) :
+        PipelineEvent(StreamStatus, src), status(status), owner(owner)
+    {}
+    static QEvent::Type type()
+    {
+        return StreamStatus;
+    }
+    StreamStatusType getStatus()
+    {
+        return status;
+    }
+    const char *getStatusName()
+    {
+        return statusName(status);
+    }
+    static const char *statusName(StreamStatusType status)
+    {
+        switch (status) {
+        case StreamStatusEvent::Create:
+            return "Create";
+
+        case StreamStatusEvent::Enter:
+            return "Enter";
+
+        case StreamStatusEvent::Leave:
+            return "Leave";
+
+        case StreamStatusEvent::Destroy:
+            return "Destroy";
+
+        case StreamStatusEvent::Start:
+            return "Start";
+
+        case StreamStatusEvent::Pause:
+            return "Pause";
+
+        case StreamStatusEvent::Stop:
+            return "Stop";
+
+        case StreamStatusEvent::Null:
+            return "Null";
+        }
+        return "<unknown>";
+    }
+    QString getOwner()
+    {
+        return owner;
+    }
+private:
+    StreamStatusType status;
+    QString owner;
+};
+
+class ClockEvent : public PipelineEvent {
+public:
+    ClockEvent(QEvent::Type type, QString src, QString name) : PipelineEvent(type, src), name(name)
+    {}
+    QString getName()
+    {
+        return name;
+    }
+private:
+    QString name;
+};
+
+class NewClockEvent : public ClockEvent {
+public:
+    NewClockEvent(QString src, QString name) : ClockEvent(NewClock, src, name)
+    {}
+    static QEvent::Type type()
+    {
+        return NewClock;
+    }
+};
+
+class ClockProvideEvent : public ClockEvent {
+public:
+    ClockProvideEvent(QString src, QString name, bool ready) : ClockEvent(ClockProvide, src, name), ready(ready)
+    {}
+    static QEvent::Type type()
+    {
+        return ClockProvide;
+    }
+    bool isReady()
+    {
+        return ready;
+    }
+private:
+    bool ready;
+};
+
+
+class ClockLostEvent : public ClockEvent {
+public:
+    ClockLostEvent(QString src, QString name) : ClockEvent(ClockLost, src, name)
+    {}
+    static QEvent::Type type()
+    {
+        return ClockLost;
+    }
+};
+
+class ProgressEvent : public PipelineEvent {
+public:
+    enum ProgressType {
+        Start, Continue, Complete, Cancelled, Error
+    };
+
+    ProgressEvent(QString src, ProgressType progressType, QString code, QString text) :
+        PipelineEvent(Progress, src), progressType(progressType), code(code), text(text)
+    {}
+    static QEvent::Type type()
+    {
+        return Progress;
+    }
+    ProgressType getProgressType()
+    {
+        return progressType;
+    }
+    QString getCode()
+    {
+        return code;
+    }
+    QString getText()
+    {
+        return text;
+    }
+private:
+    ProgressType progressType;
+    QString code;
+    QString text;
+};
+
+class LatencyEvent : public PipelineEvent {
+public:
+    LatencyEvent(QString src) :
+        PipelineEvent(Latency, src)
+    {}
+    static QEvent::Type type()
+    {
+        return Latency;
+    }
+};
+
+class QosData {
+public:
+    // timestamps and live status
+    // If the message was generated by a live element
+    bool live;
+    // running_time, stream_time, timestamp and duration of the dropped buffer.
+    // Values of GST_CLOCK_TIME_NONE mean unknown values.
+    quint64 running_time;
+    quint64 stream_time;
+    quint64 timestamp;
+    quint64 duration;
+
+    // values
+    // The difference of the running-time against the deadline.
+    qint64 jitter;
+    // Long term prediction of the ideal rate relative to normal rate to get optimal quality.
+    qreal proportion; // won't work on ARM?
+    // An element dependent integer value that specifies the current quality level of the element.
+    // The default maximum quality is 1000000.
+    qint32 quality;
+
+    // stats
+    // QoS stats representing the history of the current continuous pipeline playback period.
+    // When format is GST_FORMAT_UNDEFINED both dropped and processed are invalid.
+    // Values of -1 for either processed or dropped mean unknown values.
+
+    // Units of the 'processed' and 'dropped' fields.
+    // Video sinks and video filters will use GST_FORMAT_BUFFERS (frames).
+    // Audio sinks and audio filters will likely use GST_FORMAT_DEFAULT (samples)
+    // GstFormat format;
+    // Total number of units correctly processed since the last state change to READY or a flushing operation.
+    quint64 processed;
+    // Total number of units dropped since the last state change to READY or a flushing operation.
+    quint64 dropped;
+
+    QString timestamps()
+    {
+        return QString("live: %0; running time: %1; stream time: %2; timestamp: %3; duration: %4").arg(live).arg(
+            running_time).arg(stream_time).arg(timestamp).arg(duration);
+    }
+    QString values()
+    {
+        return QString("jitter: %0; proportion: %1; quality: %2;").arg(jitter).arg(proportion).arg(quality);
+    }
+    QString stats()
+    {
+        return QString("format: %0; processed: %1; dropped: %2;").arg("").arg(processed).arg(dropped);
+    }
+};
+
+class QosEvent : public PipelineEvent {
+public:
+    QosEvent(QString src, QosData data) : PipelineEvent(Qos, src), data(data)
+    {}
+    static QEvent::Type type()
+    {
+        return Qos;
+    }
+    QosData getData()
+    {
+        return data;
+    }
+private:
+    QosData data;
+};
+
+class EosEvent : public PipelineEvent {
+public:
+    EosEvent(QString src) : PipelineEvent(Eos, src)
+    {}
+    static QEvent::Type type()
+    {
+        return Eos;
+    }
+};
+
+class MessageEvent : public PipelineEvent {
+public:
+    MessageEvent(QEvent::Type type, QString src, QString message, QString debug) :
+        PipelineEvent(type, src), message(message), debug(debug)
+    {}
+    QString getMessage()
+    {
+        return message;
+    }
+    QString getDebug()
+    {
+        return debug;
+    }
+private:
+    QString message;
+    QString debug;
+};
+
+class ErrorEvent : public MessageEvent {
+public:
+    ErrorEvent(QString src, QString message, QString debug) : MessageEvent(Error, src, message, debug)
+    {}
+    static QEvent::Type type()
+    {
+        return Error;
+    }
+};
+
+class WarningEvent : public MessageEvent {
+public:
+    WarningEvent(QString src, QString message, QString debug) : MessageEvent(Warning, src, message, debug)
+    {}
+    static QEvent::Type type()
+    {
+        return Warning;
+    }
+};
+
+class InfoEvent : public MessageEvent {
+public:
+    InfoEvent(QString src, QString message, QString debug) : MessageEvent(Info, src, message, debug)
+    {}
+    static QEvent::Type type()
+    {
+        return Info;
+    }
+};
+
+#endif /* PIPELINEEVENT_H_ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/cameraevent.cpp

@@ -0,0 +1,96 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ * Library       <2002> Ronald Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2007 David A. Schleef <ds@schleef.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "cameraevent.hpp"
+
+#include <opencv2/opencv.hpp>
+
+#include <QDebug>
+#include <QString>
+
+/**
+ * gst_video_event_new_still_frame:
+ * @in_still: boolean value for the still-frame state of the event.
+ *
+ * Creates a new Still Frame event. If @in_still is %TRUE, then the event
+ * represents the start of a still frame sequence. If it is %FALSE, then
+ * the event ends a still frame sequence.
+ *
+ * To parse an event created by gst_video_event_new_still_frame() use
+ * gst_video_event_parse_still_frame().
+ *
+ * Returns: The new GstEvent
+ */
+GstEvent *
+gst_camera_event_new_calibrated (gchar * settings)
+{
+  GstEvent *calibrated_event;
+  GstStructure *s;
+
+  s = gst_structure_new (GST_CAMERA_EVENT_CALIBRATED_NAME,
+          "undistort-settings", G_TYPE_STRING, g_strdup(settings), NULL);
+
+  calibrated_event = gst_event_new_custom (GST_EVENT_CUSTOM_BOTH, s);
+
+  return calibrated_event;
+}
+
+/**
+ * gst_video_event_parse_still_frame:
+ * @event: A #GstEvent to parse
+ * @in_still: A boolean to receive the still-frame status from the event, or NULL
+ *
+ * Parse a #GstEvent, identify if it is a Still Frame event, and
+ * return the still-frame state from the event if it is.
+ * If the event represents the start of a still frame, the in_still
+ * variable will be set to TRUE, otherwise FALSE. It is OK to pass NULL for the
+ * in_still variable order to just check whether the event is a valid still-frame
+ * event.
+ *
+ * Create a still frame event using gst_video_event_new_still_frame()
+ *
+ * Returns: %TRUE if the event is a valid still-frame event. %FALSE if not
+ */
+gboolean
+gst_camera_event_parse_calibrated (GstEvent * event, gchar ** settings)
+{
+  const GstStructure *s;
+
+  g_return_val_if_fail (event != NULL, FALSE);
+
+  if (GST_EVENT_TYPE (event) != GST_EVENT_CUSTOM_BOTH)
+      return FALSE;               /* Not a calibrated event */
+
+  s = gst_event_get_structure (event);
+  if (s == NULL
+      || !gst_structure_has_name (s, GST_CAMERA_EVENT_CALIBRATED_NAME))
+    return FALSE;               /* Not a calibrated event */
+
+  const gchar *str = gst_structure_get_string(s, "undistort-settings");
+  if (!str)
+      return FALSE;               /* Not calibrated frame event */
+
+  //qDebug() << "*** " << buf;//QString::fromStdString(buf);
+
+  *settings = g_strdup (str);
+
+  return TRUE;
+}

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/cameraevent.hpp

@@ -0,0 +1,37 @@
+/* GStreamer
+ * Copyright (C) <2011> Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_CAMERA_EVENT_H__
+#define __GST_CAMERA_EVENT_H__
+
+#include <gst/gst.h>
+
+G_BEGIN_DECLS
+
+#define GST_CAMERA_EVENT_CALIBRATED_NAME "GstEventCalibrated"
+
+/* camera calibration event creation and parsing */
+
+GstEvent *     gst_camera_event_new_calibrated (gchar * settings);
+
+gboolean       gst_camera_event_parse_calibrated (GstEvent * event, gchar ** settings);
+
+G_END_DECLS
+
+#endif /* __GST_CAMERA_EVENT_H__ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/camerautils.cpp

@@ -0,0 +1,48 @@
+/* GStreamer
+ * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>
+ * Library       <2002> Ronald Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2007 David A. Schleef <ds@schleef.org>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#include "camerautils.hpp"
+
+#include <opencv2/opencv.hpp>
+
+#include <QDebug>
+#include <QString>
+
+gchar *
+camera_serialize_undistort_settings (cv::Mat &cameraMatrix, cv::Mat &distCoeffs)
+{
+  cv::FileStorage fs(".xml", cv::FileStorage::WRITE + cv::FileStorage::MEMORY);
+  fs << "cameraMatrix" << cameraMatrix;
+  fs << "distCoeffs" << distCoeffs;
+  std::string buf = fs.releaseAndGetString();
+
+  return g_strdup(buf.c_str());
+}
+
+gboolean
+camera_deserialize_undistort_settings (gchar * str, cv::Mat &cameraMatrix, cv::Mat &distCoeffs)
+{
+  cv::FileStorage fs(str, cv::FileStorage::READ + cv::FileStorage::MEMORY);
+  fs["cameraMatrix"] >> cameraMatrix;
+  fs["distCoeffs"] >> distCoeffs;
+
+  return TRUE;
+}

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/camerautils.hpp

@@ -0,0 +1,34 @@
+/* GStreamer
+ * Copyright (C) <2011> Wim Taymans <wim.taymans@gmail.com>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_CAMERA_UTILS_H__
+#define __GST_CAMERA_UTILS_H__
+
+#include <gst/gst.h>
+#include <cv.h>
+
+G_BEGIN_DECLS
+
+gchar *camera_serialize_undistort_settings (cv::Mat &cameraMatrix, cv::Mat &distCoeffs);
+
+gboolean camera_deserialize_undistort_settings (gchar *str, cv::Mat &cameraMatrix, cv::Mat &distCoeffs);
+
+G_END_DECLS
+
+#endif /* __GST_CAMERA_UTILS_H__ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstcameracalibration.cpp

@@ -0,0 +1,954 @@
+/*
+ * GStreamer
+ * Copyright (C) 2005 Thomas Vander Stichele <thomas@apestaart.org>
+ * Copyright (C) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2008 Michael Sheldon <mike@mikeasoft.com>
+ * Copyright (C) 2011 Stefan Sauer <ensonic@users.sf.net>
+ * Copyright (C) 2014 Robert Jobbagy <jobbagy.robert@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * SECTION:element-cameracalibration
+ *
+ * Performs face detection on videos and images.
+ * If you have high cpu load you need to use videoscale with capsfilter and reduce the video resolution.
+ *
+ * The image is scaled down multiple times using the GstCameraCalibration::scale-factor
+ * until the size is &lt;= GstCameraCalibration::min-size-width or
+ * GstCameraCalibration::min-size-height.
+ *
+ * <refsect2>
+ * <title>Example launch line</title>
+ * |[
+ * gst-launch-1.0 autovideosrc ! decodebin ! colorspace ! cameracalibration ! videoconvert ! xvimagesink
+ * ]| Detect and show faces
+ * |[
+ * gst-launch-1.0 autovideosrc ! video/x-raw,width=320,height=240 ! videoconvert ! cameracalibration min-size-width=60 min-size-height=60 ! colorspace ! xvimagesink
+ * ]| Detect large faces on a smaller image
+ *
+ * </refsect2>
+ */
+
+/* FIXME: development version of OpenCV has CV_HAAR_FIND_BIGGEST_OBJECT which
+ * we might want to use if available
+ * see https://code.ros.org/svn/opencv/trunk/opencv/modules/objdetect/src/haar.cpp
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "gstcameracalibration.h"
+
+#if (CV_MAJOR_VERSION >= 3)
+#include <opencv2/imgproc.hpp>
+#endif
+#include <opencv2/calib3d.hpp>
+
+#include <gst/opencv/gstopencvutils.h>
+
+#include "camerautils.hpp"
+#include "cameraevent.hpp"
+
+#include <vector>
+
+#include <QDebug>
+
+GST_DEBUG_CATEGORY_STATIC (gst_camera_calibration_debug);
+#define GST_CAT_DEFAULT gst_camera_calibration_debug
+
+#define DEFAULT_CALIBRATON_PATTERN GST_CAMERACALIBRATION_PATTERN_CHESSBOARD
+#define DEFAULT_BOARD_WIDTH 9
+#define DEFAULT_BOARD_HEIGHT 6
+#define DEFAULT_SQUARE_SIZE 50
+#define DEFAULT_ASPECT_RATIO 1.0
+#define DEFAULT_CORNER_SUB_PIXEL true
+#define DEFAULT_ZERO_TANGENT_DISTORTION false
+#define DEFAULT_CENTER_PRINCIPAL_POINT false
+#define DEFAULT_USE_FISHEYE false
+#define DEFAULT_FRAME_COUNT 25
+#define DEFAULT_DELAY 350
+#define DEFAULT_SHOW_CORNERS true
+
+///* Filter signals and args */
+//enum
+//{
+//  /* FILL ME */
+//  LAST_SIGNAL
+//};
+
+enum
+{
+  PROP_0,
+  PROP_CALIBRATON_PATTERN,
+  PROP_BOARD_WIDTH,
+  PROP_BOARD_HEIGHT,
+  PROP_SQUARE_SIZE,
+  PROP_ASPECT_RATIO,
+  PROP_CORNER_SUB_PIXEL,
+  PROP_ZERO_TANGENT_DISTORTION,
+  PROP_CENTER_PRINCIPAL_POINT,
+  PROP_USE_FISHEYE,
+  PROP_FRAME_COUNT,
+  PROP_DELAY,
+  PROP_SHOW_CORNERS
+};
+
+enum {
+ DETECTION = 0,
+ CAPTURING = 1,
+ CALIBRATED = 2
+};
+
+#define GST_TYPE_CAMERA_CALIBRATION_PATTERN (cameracalibration_pattern_get_type ())
+
+static GType
+cameracalibration_pattern_get_type (void)
+{
+  static GType cameracalibration_pattern_type = 0;
+  static const GEnumValue cameracalibration_pattern[] = {
+    {GST_CAMERACALIBRATION_PATTERN_CHESSBOARD, "Chessboard", "chessboard"},
+    {GST_CAMERACALIBRATION_PATTERN_CIRCLES_GRID, "Circle Grids", "circle_grids"},
+    {GST_CAMERACALIBRATION_PATTERN_ASYMMETRIC_CIRCLES_GRID, "Asymmetric Circle Grids", "asymmetric_circle_grids"},
+    {0, NULL, NULL},
+  };
+
+  if (!cameracalibration_pattern_type) {
+    cameracalibration_pattern_type =
+        g_enum_register_static ("GstCameraCalibrationPattern", cameracalibration_pattern);
+  }
+  return cameracalibration_pattern_type;
+}
+
+G_DEFINE_TYPE (GstCameraCalibration, gst_camera_calibration, GST_TYPE_OPENCV_VIDEO_FILTER);
+
+static void gst_camera_calibration_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_camera_calibration_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+//static gboolean gst_camera_calibration_set_caps (GstOpencvVideoFilter * transform,
+//    gint in_width, gint in_height, gint in_depth, gint in_channels,
+//    gint out_width, gint out_height, gint out_depth, gint out_channels);
+static GstFlowReturn gst_camera_calibration_transform_frame_ip (
+    GstOpencvVideoFilter * cvfilter, GstBuffer * frame, IplImage * img);
+
+/* Clean up */
+static void
+gst_camera_calibration_finalize (GObject * obj)
+{
+  G_OBJECT_CLASS (gst_camera_calibration_parent_class)->finalize (obj);
+}
+
+/* initialize the cameracalibration's class */
+static void
+gst_camera_calibration_class_init (GstCameraCalibrationClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+  GstOpencvVideoFilterClass *opencvfilter_class = GST_OPENCV_VIDEO_FILTER_CLASS (klass);
+  GstCaps *caps;
+  GstPadTemplate *templ;
+
+  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_camera_calibration_finalize);
+  gobject_class->set_property = gst_camera_calibration_set_property;
+  gobject_class->get_property = gst_camera_calibration_get_property;
+
+  opencvfilter_class->cv_trans_ip_func =
+      gst_camera_calibration_transform_frame_ip;
+
+  g_object_class_install_property (gobject_class, PROP_CALIBRATON_PATTERN,
+      g_param_spec_enum ("pattern", "Calibration Pattern",
+          "One of the chessboard, circles, or asymmetric circle pattern",
+          GST_TYPE_CAMERA_CALIBRATION_PATTERN, DEFAULT_CALIBRATON_PATTERN,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_BOARD_WIDTH,
+      g_param_spec_int ("board-width", "Board Width",
+          "The board width in number of items",
+          1, G_MAXINT, DEFAULT_BOARD_WIDTH,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_BOARD_HEIGHT,
+      g_param_spec_int ("board-height", "Board Height",
+          "The board height in number of items",
+          1, G_MAXINT, DEFAULT_BOARD_WIDTH,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_SQUARE_SIZE,
+      g_param_spec_float ("square-size", "Square Size",
+          "The size of a square in your defined unit (point, millimeter, etc.)",
+          0.0, G_MAXFLOAT, DEFAULT_SQUARE_SIZE,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_ASPECT_RATIO,
+      g_param_spec_float ("aspect-ratio", "Aspect Ratio",
+          "The aspect ratio",
+          0.0, G_MAXFLOAT, DEFAULT_ASPECT_RATIO,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_CORNER_SUB_PIXEL,
+      g_param_spec_boolean ("corner-sub-pixel", "Corner Sub Pixel",
+          "Improve corner detection accuracy for chessboard",
+          DEFAULT_CORNER_SUB_PIXEL, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_ZERO_TANGENT_DISTORTION,
+      g_param_spec_boolean ("zero-tangent-distorsion", "Zero Tangent Distorsion",
+          "Assume zero tangential distortion",
+          DEFAULT_ZERO_TANGENT_DISTORTION, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_CENTER_PRINCIPAL_POINT,
+      g_param_spec_boolean ("center-principal-point", "Center Principal Point",
+          "Fix the principal point at the center",
+          DEFAULT_CENTER_PRINCIPAL_POINT, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_USE_FISHEYE,
+      g_param_spec_boolean ("use-fisheye", "Use Fisheye",
+          "Use fisheye camera model for calibration",
+          DEFAULT_USE_FISHEYE, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_DELAY,
+      g_param_spec_int ("delay", "Delay",
+          "Sampling periodicity in ms", 0, G_MAXINT,
+          DEFAULT_DELAY,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_FRAME_COUNT,
+      g_param_spec_int ("frame-count", "Frame Count",
+          "The number of frames to use from the input for calibration", 1, G_MAXINT,
+          DEFAULT_FRAME_COUNT,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_SHOW_CORNERS,
+      g_param_spec_boolean ("show-corners", "Show Corners",
+          "Show corners",
+          DEFAULT_SHOW_CORNERS, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+
+  gst_element_class_set_static_metadata (element_class,
+      "cameracalibration",
+      "Filter/Effect/Video",
+      "Performs camera calibration",
+      "Philippe Renon <philippe_renon@yahoo.fr>");
+
+  /* add sink and source pad templates */
+  caps = gst_opencv_caps_from_cv_image_type (CV_8UC4);
+  gst_caps_append (caps, gst_opencv_caps_from_cv_image_type (CV_8UC3));
+  gst_caps_append (caps, gst_opencv_caps_from_cv_image_type (CV_8UC1));
+  templ = gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+      gst_caps_ref (caps));
+  gst_element_class_add_pad_template (element_class, templ);
+  templ = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS, caps);
+  gst_element_class_add_pad_template (element_class, templ);
+
+//  gst_element_class_add_static_pad_template (element_class, &src_factory);
+//  gst_element_class_add_static_pad_template (element_class, &sink_factory);
+}
+
+/* initialize the new element
+ * initialize instance structure
+ */
+static void
+gst_camera_calibration_init (GstCameraCalibration * calib)
+{
+  calib->calibrationPattern = DEFAULT_CALIBRATON_PATTERN;
+  calib->boardSize.width = DEFAULT_BOARD_WIDTH;
+  calib->boardSize.height = DEFAULT_BOARD_HEIGHT;
+  calib->squareSize = DEFAULT_SQUARE_SIZE;
+  calib->aspectRatio  = DEFAULT_ASPECT_RATIO;
+  calib->cornerSubPix = DEFAULT_CORNER_SUB_PIXEL;
+  calib->calibZeroTangentDist = DEFAULT_ZERO_TANGENT_DISTORTION;
+  calib->calibFixPrincipalPoint = DEFAULT_CENTER_PRINCIPAL_POINT;
+  calib->useFisheye = DEFAULT_USE_FISHEYE;
+  calib->nrFrames = DEFAULT_FRAME_COUNT;
+  calib->delay = DEFAULT_DELAY;
+  calib->showCorners = DEFAULT_SHOW_CORNERS;
+
+  calib->flags = cv::CALIB_FIX_K4 | cv::CALIB_FIX_K5;
+  if (calib->calibFixPrincipalPoint) calib->flags |= cv::CALIB_FIX_PRINCIPAL_POINT;
+  if (calib->calibZeroTangentDist)   calib->flags |= cv::CALIB_ZERO_TANGENT_DIST;
+  if (calib->aspectRatio)            calib->flags |= cv::CALIB_FIX_ASPECT_RATIO;
+
+  if (calib->useFisheye) {
+     // the fisheye model has its own enum, so overwrite the flags
+     calib->flags = cv::fisheye::CALIB_FIX_SKEW | cv::fisheye::CALIB_RECOMPUTE_EXTRINSIC |
+                    // cv::fisheye::CALIB_FIX_K1 |
+             cv::fisheye::CALIB_FIX_K2 | cv::fisheye::CALIB_FIX_K3 | cv::fisheye::CALIB_FIX_K4;
+  }
+
+  calib->mode = CAPTURING; //DETECTION;
+  calib->prevTimestamp = 0;
+
+  calib->imagePoints.clear();
+  calib->cameraMatrix = 0;
+  calib->distCoeffs = 0;
+
+  gst_opencv_video_filter_set_in_place (
+      GST_OPENCV_VIDEO_FILTER_CAST (calib), TRUE);
+}
+
+static void
+gst_camera_calibration_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstCameraCalibration *calib = GST_CAMERA_CALIBRATION (object);
+
+  switch (prop_id) {
+    case PROP_CALIBRATON_PATTERN:
+      calib->calibrationPattern = g_value_get_enum (value);
+      break;
+    case PROP_BOARD_WIDTH:
+      calib->boardSize.width = g_value_get_int (value);
+      break;
+    case PROP_BOARD_HEIGHT:
+      calib->boardSize.height = g_value_get_int (value);
+      break;
+    case PROP_SQUARE_SIZE:
+      calib->squareSize = g_value_get_float (value);
+      break;
+    case PROP_ASPECT_RATIO:
+      calib->aspectRatio = g_value_get_float (value);
+      break;
+    case PROP_CORNER_SUB_PIXEL:
+      calib->cornerSubPix = g_value_get_boolean (value);
+      break;
+    case PROP_ZERO_TANGENT_DISTORTION:
+      calib->calibZeroTangentDist = g_value_get_boolean (value);
+      break;
+    case PROP_CENTER_PRINCIPAL_POINT:
+      calib->calibFixPrincipalPoint = g_value_get_boolean (value);
+      break;
+    case PROP_USE_FISHEYE:
+      calib->useFisheye = g_value_get_boolean (value);
+      break;
+    case PROP_FRAME_COUNT:
+      calib->nrFrames = g_value_get_int (value);
+      break;
+    case PROP_DELAY:
+      calib->delay = g_value_get_int (value);
+      break;
+    case PROP_SHOW_CORNERS:
+      calib->showCorners = g_value_get_boolean (value);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_camera_calibration_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstCameraCalibration *calib = GST_CAMERA_CALIBRATION (object);
+
+  switch (prop_id) {
+    case PROP_CALIBRATON_PATTERN:
+      g_value_set_enum (value, calib->calibrationPattern);
+      break;
+    case PROP_BOARD_WIDTH:
+      g_value_set_int (value, calib->boardSize.width);
+      break;
+    case PROP_BOARD_HEIGHT:
+      g_value_set_int (value, calib->boardSize.height);
+      break;
+    case PROP_SQUARE_SIZE:
+      g_value_set_float (value, calib->squareSize);
+      break;
+    case PROP_ASPECT_RATIO:
+      g_value_set_float (value, calib->aspectRatio);
+      break;
+    case PROP_CORNER_SUB_PIXEL:
+      g_value_set_boolean (value, calib->cornerSubPix);
+      break;
+    case PROP_ZERO_TANGENT_DISTORTION:
+      g_value_set_boolean (value, calib->calibZeroTangentDist);
+      break;
+    case PROP_CENTER_PRINCIPAL_POINT:
+      g_value_set_boolean (value, calib->calibFixPrincipalPoint);
+      break;
+    case PROP_USE_FISHEYE:
+      g_value_set_boolean (value, calib->useFisheye);
+      break;
+    case PROP_FRAME_COUNT:
+      g_value_set_int (value, calib->nrFrames);
+      break;
+    case PROP_DELAY:
+      g_value_set_int (value, calib->delay);
+      break;
+    case PROP_SHOW_CORNERS:
+      g_value_set_boolean (value, calib->showCorners);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+/* GstElement vmethod implementations */
+
+/* this function handles the link with other elements */
+//static gboolean
+//gst_camera_calibration_set_caps (GstOpencvVideoFilter * transform, gint in_width,
+//    gint in_height, gint in_depth, gint in_channels,
+//    gint out_width, gint out_height, gint out_depth, gint out_channels)
+//{
+//  GstCameraCalibration *calib;
+//
+//  calib = GST_CAMERA_CALIBRATION (transform);
+//
+//  if (calib->cvGray)
+//    cvReleaseImage (&calib->cvGray);
+//
+//  calib->cvGray = cvCreateImage (cvSize (in_width, in_height), IPL_DEPTH_8U,
+//      1);
+//
+//  return TRUE;
+//}
+
+//static GstMessage *
+//gst_camera_calibration_message_new (GstCameraCalibration * calib, GstBuffer * buf)
+//{
+//  GstBaseTransform *trans = GST_BASE_TRANSFORM_CAST (calib);
+//  GstStructure *s;
+//  GstClockTime running_time, stream_time;
+//
+//  running_time = gst_segment_to_running_time (&trans->segment, GST_FORMAT_TIME,
+//      GST_BUFFER_TIMESTAMP (buf));
+//  stream_time = gst_segment_to_stream_time (&trans->segment, GST_FORMAT_TIME,
+//      GST_BUFFER_TIMESTAMP (buf));
+//
+//  s = gst_structure_new ("cameracalibration",
+//      "timestamp", G_TYPE_UINT64, GST_BUFFER_TIMESTAMP (buf),
+//      "stream-time", G_TYPE_UINT64, stream_time,
+//      "running-time", G_TYPE_UINT64, running_time,
+//      "duration", G_TYPE_UINT64, GST_BUFFER_DURATION (buf), NULL);
+//
+//  return gst_message_new_element (GST_OBJECT (calib), s);
+//}
+
+void camera_calibration_run(GstCameraCalibration *calib, IplImage *img);
+
+/*
+ * Performs the camera calibration
+ */
+static GstFlowReturn
+gst_camera_calibration_transform_frame_ip (GstOpencvVideoFilter * cvfilter,
+    G_GNUC_UNUSED GstBuffer * frame, IplImage * img)
+{
+  GstCameraCalibration *calib = GST_CAMERA_CALIBRATION (cvfilter);
+
+  camera_calibration_run(calib, img);
+
+  return GST_FLOW_OK;
+}
+
+
+/* entry point to initialize the plug-in
+ * initialize the plug-in itself
+ * register the element factories and other features
+ */
+gboolean
+gst_camera_calibration_plugin_init (GstPlugin * plugin)
+{
+  /* debug category for filtering log messages */
+  GST_DEBUG_CATEGORY_INIT (gst_camera_calibration_debug, "cameracalibration",
+      0,
+      "Performs camera calibration");
+
+  return gst_element_register (plugin, "cameracalibration", GST_RANK_NONE,
+      GST_TYPE_CAMERA_CALIBRATION);
+}
+
+//    void validate()
+//    {
+//        goodInput = true;
+//        if (boardSize.width <= 0 || boardSize.height <= 0)
+//        {
+//            cerr << "Invalid Board size: " << boardSize.width << " " << boardSize.height << endl;
+//            goodInput = false;
+//        }
+//        if (squareSize <= 10e-6)
+//        {
+//            cerr << "Invalid square size " << squareSize << endl;
+//            goodInput = false;
+//        }
+//        if (nrFrames <= 0)
+//        {
+//            cerr << "Invalid number of frames " << nrFrames << endl;
+//            goodInput = false;
+//        }
+//
+//        if (input.empty())      // Check for valid input
+//                inputType = INVALID;
+//        else
+//        {
+//            if (input[0] >= '0' && input[0] <= '9')
+//            {
+//                stringstream ss(input);
+//                ss >> cameraID;
+//                inputType = CAMERA;
+//            }
+//            else
+//            {
+//                if (readStringList(input, imageList))
+//                {
+//                    inputType = IMAGE_LIST;
+//                    nrFrames = (nrFrames < (int)imageList.size()) ? nrFrames : (int)imageList.size();
+//                }
+//                else
+//                    inputType = VIDEO_FILE;
+//            }
+//            if (inputType == CAMERA)
+//                inputCapture.open(cameraID);
+//            if (inputType == VIDEO_FILE)
+//                inputCapture.open(input);
+//            if (inputType != IMAGE_LIST && !inputCapture.isOpened())
+//                    inputType = INVALID;
+//        }
+//        if (inputType == INVALID)
+//        {
+//            cerr << " Input does not exist: " << input;
+//            goodInput = false;
+//        }
+//
+//        flag = CALIB_FIX_K4 | CALIB_FIX_K5;
+//        if(calibFixPrincipalPoint) flag |= CALIB_FIX_PRINCIPAL_POINT;
+//        if(calibZeroTangentDist)   flag |= CALIB_ZERO_TANGENT_DIST;
+//        if(aspectRatio)            flag |= CALIB_FIX_ASPECT_RATIO;
+//
+//        if (useFisheye) {
+//            // the fisheye model has its own enum, so overwrite the flags
+//            flag = fisheye::CALIB_FIX_SKEW | fisheye::CALIB_RECOMPUTE_EXTRINSIC |
+//                   // fisheye::CALIB_FIX_K1 |
+//                   fisheye::CALIB_FIX_K2 | fisheye::CALIB_FIX_K3 | fisheye::CALIB_FIX_K4;
+//        }
+//
+//        calibrationPattern = NOT_EXISTING;
+//        if (!patternToUse.compare("CHESSBOARD")) calibrationPattern = CHESSBOARD;
+//        if (!patternToUse.compare("CIRCLES_GRID")) calibrationPattern = CIRCLES_GRID;
+//        if (!patternToUse.compare("ASYMMETRIC_CIRCLES_GRID")) calibrationPattern = ASYMMETRIC_CIRCLES_GRID;
+//        if (calibrationPattern == NOT_EXISTING)
+//        {
+//            cerr << " Camera calibration mode does not exist: " << patternToUse << endl;
+//            goodInput = false;
+//        }
+//        atImageList = 0;
+//
+//    }
+
+bool runCalibration(GstCameraCalibration *calib, cv::Size imageSize, cv::Mat& cameraMatrix, cv::Mat& distCoeffs,
+                           std::vector<std::vector<cv::Point2f> > imagePoints );
+
+void doCalibration(GstElement *element, gpointer user_data);
+
+void camera_calibration_run(GstCameraCalibration *calib, IplImage *img)
+{
+    cv::Mat view = cv::cvarrToMat(img);
+
+    // For camera only take new samples after delay time
+    if (calib->mode == CAPTURING) {
+
+        // get_input
+        cv::Size imageSize = view.size();
+
+        // find_pattern
+        // FIXME find ways to reduce CPU usage
+        // don't do it on all frames ? will it help ? corner display will be affected.
+        // in a separate frame?
+        // in a separate element that gets composited back into the main stream (video is tee-d into it and can then be decimated, scaled, etc..)
+
+        std::vector<cv::Point2f> pointBuf;
+        bool found;
+        int chessBoardFlags = cv::CALIB_CB_ADAPTIVE_THRESH | cv::CALIB_CB_NORMALIZE_IMAGE;
+
+        if (!calib->useFisheye) {
+            // fast check erroneously fails with high distortions like fisheye
+            chessBoardFlags |= cv::CALIB_CB_FAST_CHECK;
+        }
+
+        // Find feature points on the input format
+        switch(calib->calibrationPattern) {
+        case GST_CAMERACALIBRATION_PATTERN_CHESSBOARD:
+            found = cv::findChessboardCorners(view, calib->boardSize, pointBuf, chessBoardFlags);
+            break;
+        case GST_CAMERACALIBRATION_PATTERN_CIRCLES_GRID:
+            found = cv::findCirclesGrid(view, calib->boardSize, pointBuf);
+            break;
+        case GST_CAMERACALIBRATION_PATTERN_ASYMMETRIC_CIRCLES_GRID:
+            found = cv::findCirclesGrid(view, calib->boardSize, pointBuf, cv::CALIB_CB_ASYMMETRIC_GRID );
+            break;
+        default:
+            found = false;
+            break;
+        }
+
+        bool blinkOutput = false;
+        if (found) {
+            // improve the found corners' coordinate accuracy for chessboard
+            if (calib->calibrationPattern == GST_CAMERACALIBRATION_PATTERN_CHESSBOARD && calib->cornerSubPix) {
+                // FIXME findChessboardCorners and alike do a cv::COLOR_BGR2GRAY (and a histogram balance)
+                // the color convert should be done once (if needed) and shared
+                // FIXME keep viewGray around to avoid reallocating it each time...
+                cv::Mat viewGray;
+                cv::cvtColor(view, viewGray, cv::COLOR_BGR2GRAY);
+                cv::cornerSubPix(viewGray, pointBuf, cv::Size(11, 11),
+                        cv::Size(-1, -1), cv::TermCriteria(cv::TermCriteria::EPS + cv::TermCriteria::COUNT, 30, 0.1));
+            }
+
+            // For camera only take new samples after delay time
+            if ((calib->mode == CAPTURING) && ((clock() - calib->prevTimestamp) > calib->delay * 1e-3 * CLOCKS_PER_SEC)) {
+                calib->imagePoints.push_back(pointBuf);
+                calib->prevTimestamp = clock();
+                blinkOutput = true;
+            }
+
+            // Draw the cornerfilter
+            if (calib->showCorners) {
+                cv::drawChessboardCorners(view, calib->boardSize, cv::Mat(pointBuf), found);
+            }
+        }
+
+        // If got enough frames then stop calibration and show result
+        if (calib->mode == CAPTURING && calib->imagePoints.size() >= (size_t)calib->nrFrames) {
+
+            //GstElementCallAsyncFunc func;
+            //gst_element_call_async (GST_ELEMENT (calib), /*GstElementCallAsyncFunc*/ doCalibration, NULL, NULL);
+
+            if (runCalibration(calib, imageSize, calib->cameraMatrix, calib->distCoeffs, calib->imagePoints)) {
+                calib->mode = CALIBRATED;
+
+                GstPad *sinkPad = GST_BASE_TRANSFORM_SINK_PAD (calib);
+                //GstPad *srcPad = GST_BASE_TRANSFORM_SRC_PAD (calib);
+                GstEvent *event;
+                //gboolean result;
+
+                // create calibrated event and send upstream and downstream
+                // FIXME should keep settings around for answering queries
+                gchar *settings = camera_serialize_undistort_settings(calib->cameraMatrix, calib->distCoeffs);
+                event = gst_camera_event_new_calibrated(settings);
+                g_free (settings);
+
+                //gst_event_ref(event);
+                GST_LOG_OBJECT (sinkPad, "Sending upstream event %s.", GST_EVENT_TYPE_NAME (event));
+                if (!gst_pad_push_event (sinkPad, event)) {
+                  GST_WARNING_OBJECT (sinkPad, "Sending upstream event %p (%s) failed.",
+                      event, GST_EVENT_TYPE_NAME (event));
+                }
+//                GST_LOG_OBJECT (srcPad, "Sending downstream event %s.", GST_EVENT_TYPE_NAME (event));
+//                if (!gst_pad_push_event (srcPad, event)) {
+//                  GST_WARNING_OBJECT (srcPad, "Sending downstream event %p (%s) failed.",
+//                      event, GST_EVENT_TYPE_NAME (event));
+//                }
+            } else {
+                calib->mode = DETECTION;
+            }
+        }
+
+        if (calib->mode == CAPTURING && blinkOutput) {
+            bitwise_not(view, view);
+        }
+
+    }
+
+    // Output Text
+    // FIXME all additional rendering (text, corners, ...) should be done with cairo or another gst framework.
+    // this will relax the conditions on the input format (RBG only at the moment).
+    // the calibration itself accepts more formats...
+
+    std::string msg = (calib->mode == CAPTURING) ? "100/100" :
+            (calib->mode == CALIBRATED) ? "Calibrated" : "Press 'g' to start";
+    int baseLine = 0;
+    cv::Size textSize = cv::getTextSize(msg, 1, 1, 1, &baseLine);
+    cv::Point textOrigin(view.cols - 2 * textSize.width - 10, view.rows - 2 * baseLine - 10);
+
+    if (calib->mode == CAPTURING) {
+      msg = cv::format( "%d/%d", (int)calib->imagePoints.size(), calib->nrFrames );
+    }
+
+    const cv::Scalar RED(0,0,255);
+    const cv::Scalar GREEN(0,255,0);
+
+    cv::putText(view, msg, textOrigin, 1, 1, calib->mode == CALIBRATED ?  GREEN : RED);
+}
+
+void doCalibration(__attribute__((unused)) GstElement *element, __attribute__((unused)) gpointer user_data)
+{
+    // GstCameraCalibration *calib = GST_CAMERA_CALIBRATION (element);
+}
+
+static double computeReprojectionErrors( const std::vector<std::vector<cv::Point3f> >& objectPoints,
+                                         const std::vector<std::vector<cv::Point2f> >& imagePoints,
+                                         const std::vector<cv::Mat>& rvecs, const std::vector<cv::Mat>& tvecs,
+                                         const cv::Mat& cameraMatrix , const cv::Mat& distCoeffs,
+                                         std::vector<float>& perViewErrors, bool fisheye)
+{
+    std::vector<cv::Point2f> imagePoints2;
+    size_t totalPoints = 0;
+    double totalErr = 0, err;
+    perViewErrors.resize(objectPoints.size());
+
+    for(size_t i = 0; i < objectPoints.size(); ++i)
+    {
+        if (fisheye)
+        {
+            cv::fisheye::projectPoints(objectPoints[i], imagePoints2, rvecs[i], tvecs[i], cameraMatrix,
+                                   distCoeffs);
+        }
+        else
+        {
+            cv::projectPoints(objectPoints[i], rvecs[i], tvecs[i], cameraMatrix, distCoeffs, imagePoints2);
+        }
+        err = cv::norm(imagePoints[i], imagePoints2, cv::NORM_L2);
+
+        size_t n = objectPoints[i].size();
+        perViewErrors[i] = (float) std::sqrt(err*err/n);
+        totalErr        += err*err;
+        totalPoints     += n;
+    }
+
+    return std::sqrt(totalErr/totalPoints);
+}
+
+static void calcBoardCornerPositions(cv::Size boardSize, float squareSize, std::vector<cv::Point3f>& corners,
+        gint patternType /*= CHESSBOARD*/)
+{
+    corners.clear();
+
+    switch(patternType)
+    {
+    case GST_CAMERACALIBRATION_PATTERN_CHESSBOARD:
+    case GST_CAMERACALIBRATION_PATTERN_CIRCLES_GRID:
+        for( int i = 0; i < boardSize.height; ++i)
+            for( int j = 0; j < boardSize.width; ++j)
+                corners.push_back(cv::Point3f(j * squareSize, i * squareSize, 0));
+        break;
+
+    case GST_CAMERACALIBRATION_PATTERN_ASYMMETRIC_CIRCLES_GRID:
+        for( int i = 0; i < boardSize.height; i++)
+            for( int j = 0; j < boardSize.width; j++)
+                corners.push_back(cv::Point3f((2 * j + i % 2) * squareSize, i * squareSize, 0));
+        break;
+    default:
+        break;
+    }
+}
+
+static bool runCalibration(GstCameraCalibration *calib, cv::Size& imageSize, cv::Mat& cameraMatrix, cv::Mat& distCoeffs,
+                            std::vector<std::vector<cv::Point2f> > imagePoints, std::vector<cv::Mat>& rvecs, std::vector<cv::Mat>& tvecs,
+                            std::vector<float>& reprojErrs, double& totalAvgErr)
+{
+    //! [fixed_aspect]
+    cameraMatrix = cv::Mat::eye(3, 3, CV_64F);
+    if (calib->flags & cv::CALIB_FIX_ASPECT_RATIO) {
+        cameraMatrix.at<double>(0,0) = calib->aspectRatio;
+    }
+    //! [fixed_aspect]
+    if (calib->useFisheye) {
+        distCoeffs = cv::Mat::zeros(4, 1, CV_64F);
+    } else {
+        distCoeffs = cv::Mat::zeros(8, 1, CV_64F);
+    }
+
+    std::vector<std::vector<cv::Point3f> > objectPoints(1);
+    calcBoardCornerPositions(calib->boardSize, calib->squareSize, objectPoints[0], calib->calibrationPattern);
+
+    objectPoints.resize(imagePoints.size(), objectPoints[0]);
+
+    // Find intrinsic and extrinsic camera parameters
+    double rms;
+
+    if (calib->useFisheye) {
+        cv::Mat _rvecs, _tvecs;
+        rms = cv::fisheye::calibrate(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, _rvecs,
+                                 _tvecs, calib->flags);
+
+        rvecs.reserve(_rvecs.rows);
+        tvecs.reserve(_tvecs.rows);
+        for(int i = 0; i < int(objectPoints.size()); i++){
+            rvecs.push_back(_rvecs.row(i));
+            tvecs.push_back(_tvecs.row(i));
+        }
+    } else {
+        rms = cv::calibrateCamera(objectPoints, imagePoints, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs,
+                              calib->flags);
+    }
+
+    GST_LOG_OBJECT (calib,
+       "Re-projection error reported by calibrateCamera: %f", rms);
+    qDebug() << "Re-projection error reported by calibrateCamera:" <<  rms;
+
+
+    bool ok = checkRange(cameraMatrix) && checkRange(distCoeffs);
+
+    totalAvgErr = computeReprojectionErrors(objectPoints, imagePoints, rvecs, tvecs, cameraMatrix,
+                                            distCoeffs, reprojErrs, calib->useFisheye);
+
+    return ok;
+}
+
+// Print camera parameters to the output file
+//static void saveCameraParams( Settings& s, Size& imageSize, Mat& cameraMatrix, Mat& distCoeffs,
+//                              const vector<Mat>& rvecs, const vector<Mat>& tvecs,
+//                              const vector<float>& reprojErrs, const vector<vector<Point2f> >& imagePoints,
+//                              double totalAvgErr)
+//{
+//    FileStorage fs( s.outputFileName, FileStorage::WRITE);
+//
+//    time_t tm;
+//    time( &tm);
+//    struct tm *t2 = localtime( &tm);
+//    char buf[1024];
+//    strftime( buf, sizeof(buf), "%c", t2);
+//
+//    fs << "calibration_time" << buf;
+//
+//    if (!rvecs.empty() || !reprojErrs.empty())
+//        fs << "nr_of_frames" << (int)std::max(rvecs.size(), reprojErrs.size());
+//    fs << "image_width" << imageSize.width;
+//    fs << "image_height" << imageSize.height;
+//    fs << "board_width" << s.boardSize.width;
+//    fs << "board_height" << s.boardSize.height;
+//    fs << "square_size" << s.squareSize;
+//
+//    if (s.flag & CALIB_FIX_ASPECT_RATIO)
+//        fs << "fix_aspect_ratio" << s.aspectRatio;
+//
+//    if (s.flag)
+//    {
+//        if (s.useFisheye)
+//        {
+//            sprintf(buf, "flags:%s%s%s%s%s%s",
+//                     s.flag & fisheye::CALIB_FIX_SKEW ? " +fix_skew" : "",
+//                     s.flag & fisheye::CALIB_FIX_K1 ? " +fix_k1" : "",
+//                     s.flag & fisheye::CALIB_FIX_K2 ? " +fix_k2" : "",
+//                     s.flag & fisheye::CALIB_FIX_K3 ? " +fix_k3" : "",
+//                     s.flag & fisheye::CALIB_FIX_K4 ? " +fix_k4" : "",
+//                     s.flag & fisheye::CALIB_RECOMPUTE_EXTRINSIC ? " +recompute_extrinsic" : "");
+//        }
+//        else
+//        {
+//            sprintf(buf, "flags:%s%s%s%s",
+//                     s.flag & CALIB_USE_INTRINSIC_GUESS ? " +use_intrinsic_guess" : "",
+//                     s.flag & CALIB_FIX_ASPECT_RATIO ? " +fix_aspectRatio" : "",
+//                     s.flag & CALIB_FIX_PRINCIPAL_POINT ? " +fix_principal_point" : "",
+//                     s.flag & CALIB_ZERO_TANGENT_DIST ? " +zero_tangent_dist" : "");
+//        }
+//        cvWriteComment(*fs, buf, 0);
+//    }
+//
+//    fs << "flags" << s.flag;
+//
+//    fs << "fisheye_model" << s.useFisheye;
+//
+//    fs << "camera_matrix" << cameraMatrix;
+//    fs << "distortion_coefficients" << distCoeffs;
+//
+//    fs << "avg_reprojection_error" << totalAvgErr;
+//    if (s.writeExtrinsics && !reprojErrs.empty())
+//        fs << "per_view_reprojection_errors" << Mat(reprojErrs);
+//
+//    if(s.writeExtrinsics && !rvecs.empty() && !tvecs.empty())
+//    {
+//        CV_Assert(rvecs[0].type() == tvecs[0].type());
+//        Mat bigmat((int)rvecs.size(), 6, rvecs[0].type());
+//        for( size_t i = 0; i < rvecs.size(); i++)
+//        {
+//            Mat r = bigmat(Range(int(i), int(i+1)), Range(0,3));
+//            Mat t = bigmat(Range(int(i), int(i+1)), Range(3,6));
+//
+//            CV_Assert(rvecs[i].rows == 3 && rvecs[i].cols == 1);
+//            CV_Assert(tvecs[i].rows == 3 && tvecs[i].cols == 1);
+//            //*.t() is MatExpr (not Mat) so we can use assignment operator
+//            r = rvecs[i].t();
+//            t = tvecs[i].t();
+//        }
+//        //cvWriteComment( *fs, "a set of 6-tuples (rotation vector + translation vector) for each view", 0);
+//        fs << "extrinsic_parameters" << bigmat;
+//    }
+//
+//    if(s.writePoints && !imagePoints.empty())
+//    {
+//        Mat imagePtMat((int)imagePoints.size(), (int)imagePoints[0].size(), CV_32FC2);
+//        for( size_t i = 0; i < imagePoints.size(); i++)
+//        {
+//            Mat r = imagePtMat.row(int(i)).reshape(2, imagePtMat.cols);
+//            Mat imgpti(imagePoints[i]);
+//            imgpti.copyTo(r);
+//        }
+//        fs << "image_points" << imagePtMat;
+//    }
+//}
+
+//! [run_and_save]
+//bool runCalibrationAndSave(Settings& s, Size imageSize, Mat& cameraMatrix, Mat& distCoeffs,
+//                           vector<vector<Point2f> > imagePoints)
+//{
+//    vector<Mat> rvecs, tvecs;
+//    vector<float> reprojErrs;
+//    double totalAvgErr = 0;
+//
+//    bool ok = runCalibration(s, imageSize, cameraMatrix, distCoeffs, imagePoints, rvecs, tvecs, reprojErrs,
+//                             totalAvgErr);
+//    cout << (ok ? "Calibration succeeded" : "Calibration failed")
+//         << ". avg re projection error = " << totalAvgErr << endl;
+//
+////    if (ok)
+////        saveCameraParams(s, imageSize, cameraMatrix, distCoeffs, rvecs, tvecs, reprojErrs, imagePoints,
+////                         totalAvgErr);
+//    return ok;
+//}
+//! [run_and_save]
+
+bool runCalibration(GstCameraCalibration *calib, cv::Size imageSize, cv::Mat& cameraMatrix, cv::Mat& distCoeffs,
+        std::vector<std::vector<cv::Point2f> > imagePoints)
+{
+    std::vector<cv::Mat> rvecs, tvecs;
+    std::vector<float> reprojErrs;
+    double totalAvgErr = 0;
+
+    bool ok = runCalibration(calib, imageSize, cameraMatrix, distCoeffs, imagePoints, rvecs, tvecs, reprojErrs,
+                             totalAvgErr);
+    GST_LOG_OBJECT (calib,
+       (ok ? "Calibration succeeded" : "Calibration failed"));// + ". avg re projection error = " + totalAvgErr);
+
+    return ok;
+}

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstcameracalibration.h

@@ -0,0 +1,114 @@
+/*
+ * GStreamer
+ * Copyright (C) 2005 Thomas Vander Stichele <thomas@apestaart.org>
+ * Copyright (C) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2008 Michael Sheldon <mike@mikeasoft.com>
+ * Copyright (C) 2011 Stefan Sauer <ensonic@users.sf.net>
+ * Copyright (C) 2011 Robert Jobbagy <jobbagy.robert@gmail.com>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_CAMERA_CALIBRATION_H__
+#define __GST_CAMERA_CALIBRATION_H__
+
+#include <gst/gst.h>
+
+#include <gst/opencv/gstopencvvideofilter.h>
+
+#include <opencv2/core.hpp>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_CAMERA_CALIBRATION \
+  (gst_camera_calibration_get_type())
+#define GST_CAMERA_CALIBRATION(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CAMERA_CALIBRATION,GstCameraCalibration))
+#define GST_CAMERA_CALIBRATION_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CAMERA_CALIBRATION,GstCameraCalibrationClass))
+#define GST_IS_CAMERA_CALIBRATION(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CAMERA_CALIBRATION))
+#define GST_IS_CAMERA_CALIBRATION_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CAMERA_CALIBRATION))
+typedef struct _GstCameraCalibration GstCameraCalibration;
+typedef struct _GstCameraCalibrationClass GstCameraCalibrationClass;
+
+enum _GstCameraCalibrationPattern {
+    GST_CAMERACALIBRATION_PATTERN_CHESSBOARD,
+    GST_CAMERACALIBRATION_PATTERN_CIRCLES_GRID,
+    GST_CAMERACALIBRATION_PATTERN_ASYMMETRIC_CIRCLES_GRID
+};
+
+struct _GstCameraCalibration
+{
+  GstOpencvVideoFilter cvfilter;
+  
+  // settings
+  gint calibrationPattern;     // One of the chessboard, circles, or asymmetric circle pattern
+  cv::Size boardSize;          // The size of the board -> Number of items by width and height
+  float squareSize;            // The size of a square in your defined unit (point, millimeter,etc).
+  float aspectRatio;           // The aspect ratio
+  bool cornerSubPix;           //
+  bool calibZeroTangentDist;   // Assume zero tangential distortion
+  bool calibFixPrincipalPoint; // Fix the principal point at the center
+  bool useFisheye;             // use fisheye camera model for calibration
+  int nrFrames;                // The number of frames to use from the input for calibration
+  int delay;                   // In case of a video input
+  bool showUndistorsed;        // Show undistorted images after calibration
+  bool showCorners;            // Show corners
+
+  // state
+  int flags;
+  int mode;
+  clock_t prevTimestamp;
+  std::vector<std::vector<cv::Point2f> > imagePoints;
+  cv::Mat cameraMatrix, distCoeffs;
+};
+
+struct _GstCameraCalibrationClass
+{
+  GstOpencvVideoFilterClass parent_class;
+};
+
+GType gst_camera_calibration_get_type (void);
+
+gboolean gst_camera_calibration_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+#endif /* __GST_CAMERA_CALIBRATION_H__ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstcameraundistort.cpp

@@ -0,0 +1,515 @@
+/*
+ * GStreamer
+ * Copyright (C) 2005 Thomas Vander Stichele <thomas@apestaart.org>
+ * Copyright (C) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2008 Michael Sheldon <mike@mikeasoft.com>
+ * Copyright (C) 2011 Stefan Sauer <ensonic@users.sf.net>
+ * Copyright (C) 2014 Robert Jobbagy <jobbagy.robert@gmail.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/**
+ * SECTION:element-cameraundistort
+ *
+ * Performs face detection on videos and images.
+ * If you have high cpu load you need to use videoscale with capsfilter and reduce the video resolution.
+ *
+ * The image is scaled down multiple times using the GstCameraCalibration::scale-factor
+ * until the size is &lt;= GstCameraCalibration::min-size-width or
+ * GstCameraCalibration::min-size-height.
+ *
+ * <refsect2>
+ * <title>Example launch line</title>
+ * |[
+ * gst-launch-1.0 autovideosrc ! decodebin ! colorspace ! cameraundistort ! videoconvert ! xvimagesink
+ * ]| Detect and show faces
+ * |[
+ * gst-launch-1.0 autovideosrc ! video/x-raw,width=320,height=240 ! videoconvert ! cameraundistort min-size-width=60 min-size-height=60 ! colorspace ! xvimagesink
+ * ]| Detect large faces on a smaller image
+ *
+ * </refsect2>
+ */
+
+/* FIXME: development version of OpenCV has CV_HAAR_FIND_BIGGEST_OBJECT which
+ * we might want to use if available
+ * see https://code.ros.org/svn/opencv/trunk/opencv/modules/objdetect/src/haar.cpp
+ */
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include <vector>
+
+#include "camerautils.hpp"
+#include "cameraevent.hpp"
+
+#include <QDebug>
+#include <QElapsedTimer>
+
+#include "gstcameraundistort.h"
+
+#if (CV_MAJOR_VERSION >= 3)
+#include <opencv2/imgproc.hpp>
+#endif
+#include <opencv2/calib3d.hpp>
+
+#include <gst/opencv/gstopencvutils.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_camera_undistort_debug);
+#define GST_CAT_DEFAULT gst_camera_undistort_debug
+
+#define DEFAULT_SHOW_UNDISTORTED true
+#define DEFAULT_ALPHA 1.0
+#define DEFAULT_CROP true
+
+enum
+{
+  PROP_0,
+  PROP_SHOW_UNDISTORTED,
+  PROP_ALPHA,
+  PROP_CROP,
+  PROP_SETTINGS
+};
+
+/*#define GST_CAMERA_UNDISTORT_GET_LOCK(playsink) (&((GstCameraUndistort *)undist)->lock)
+#define GST_CAMERA_UNDISTORT_LOCK(undist)     G_STMT_START { \
+  GST_LOG_OBJECT (playsink, "locking from thread %p", g_thread_self ()); \
+  g_rec_mutex_lock (GST_CAMERA_UNDISTORT_GET_LOCK (undist)); \
+  GST_LOG_OBJECT (playsink, "locked from thread %p", g_thread_self ()); \
+} G_STMT_END
+#define GST_CAMERA_UNDISTORT_UNLOCK(undist)   G_STMT_START { \
+  GST_LOG_OBJECT (playsink, "unlocking from thread %p", g_thread_self ()); \
+  g_rec_mutex_unlock (GST_CAMERA_UNDISTORT_GET_LOCK (undist)); \
+} G_STMT_END*/
+
+G_DEFINE_TYPE (GstCameraUndistort, gst_camera_undistort, GST_TYPE_OPENCV_VIDEO_FILTER);
+
+static void gst_camera_undistort_dispose (GObject * object);
+static void gst_camera_undistort_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec);
+static void gst_camera_undistort_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec);
+
+static gboolean gst_camera_undistort_set_info (GstOpencvVideoFilter * cvfilter,
+    gint in_width, gint in_height, gint in_depth, gint in_channels,
+    gint out_width, gint out_height, gint out_depth, gint out_channels);
+static GstFlowReturn gst_camera_undistort_transform_frame (
+    GstOpencvVideoFilter * cvfilter,
+    GstBuffer * frame, IplImage * img,
+    GstBuffer * outframe, IplImage * outimg);
+
+static gboolean gst_camera_undistort_sink_event (GstBaseTransform *trans, GstEvent *event);
+static gboolean gst_camera_undistort_src_event (GstBaseTransform *trans, GstEvent *event);
+
+static void camera_undistort_run(GstCameraUndistort *undist, IplImage *img, IplImage *outimg);
+static gboolean camera_undistort_init_undistort_rectify_map(GstCameraUndistort *undist);
+
+/* initialize the cameraundistort's class */
+static void
+gst_camera_undistort_class_init (GstCameraUndistortClass * klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+  GstElementClass *element_class = GST_ELEMENT_CLASS (klass);
+  GstBaseTransformClass *trans_class = GST_BASE_TRANSFORM_CLASS (klass);
+  GstOpencvVideoFilterClass *opencvfilter_class = GST_OPENCV_VIDEO_FILTER_CLASS (klass);
+
+  GstCaps *caps;
+  GstPadTemplate *templ;
+
+  gobject_class->dispose = gst_camera_undistort_dispose;
+  gobject_class->set_property = gst_camera_undistort_set_property;
+  gobject_class->get_property = gst_camera_undistort_get_property;
+
+  trans_class->sink_event =
+      GST_DEBUG_FUNCPTR (gst_camera_undistort_sink_event);
+  trans_class->src_event =
+      GST_DEBUG_FUNCPTR (gst_camera_undistort_src_event);
+
+  opencvfilter_class->cv_set_caps = gst_camera_undistort_set_info;
+  opencvfilter_class->cv_trans_func =
+      gst_camera_undistort_transform_frame;
+
+  g_object_class_install_property (gobject_class, PROP_SHOW_UNDISTORTED,
+      g_param_spec_boolean ("show-undistorted", "Show Undistorted",
+          "Show undistorted images",
+          DEFAULT_SHOW_UNDISTORTED, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_ALPHA,
+      g_param_spec_float ("alpha", "Pixels",
+          "Pixels bla bla...",
+          0.0, 1.0, DEFAULT_ALPHA,
+          (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  g_object_class_install_property (gobject_class, PROP_SETTINGS,
+      g_param_spec_string ("settings", "Settings",
+          "Undistort settings (OpenCV serialized opaque string)",
+          NULL, (GParamFlags) (G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS)));
+
+  gst_element_class_set_static_metadata (element_class,
+      "cameraundistort",
+      "Filter/Effect/Video",
+      "Performs camera undistort",
+      "Philippe Renon <philippe_renon@yahoo.fr>");
+
+  /* add sink and source pad templates */
+  caps = gst_opencv_caps_from_cv_image_type (CV_16UC1);
+  gst_caps_append (caps, gst_opencv_caps_from_cv_image_type (CV_8UC4));
+  gst_caps_append (caps, gst_opencv_caps_from_cv_image_type (CV_8UC3));
+  gst_caps_append (caps, gst_opencv_caps_from_cv_image_type (CV_8UC1));
+  templ = gst_pad_template_new ("sink", GST_PAD_SINK, GST_PAD_ALWAYS,
+      gst_caps_ref (caps));
+  gst_element_class_add_pad_template (element_class, templ);
+  templ = gst_pad_template_new ("src", GST_PAD_SRC, GST_PAD_ALWAYS, caps);
+  gst_element_class_add_pad_template (element_class, templ);
+}
+
+/* initialize the new element
+ * initialize instance structure
+ */
+static void
+gst_camera_undistort_init (GstCameraUndistort * undist)
+{
+  undist->showUndistorted = DEFAULT_SHOW_UNDISTORTED;
+  undist->alpha = DEFAULT_ALPHA;
+  undist->crop = DEFAULT_CROP;
+
+  undist->doUndistort = false;
+  undist->settingsChanged = false;
+
+  undist->cameraMatrix = 0;
+  undist->distCoeffs = 0;
+  undist->map1 = 0;
+  undist->map2 = 0;
+  //undist->validPixROI = 0;
+
+  undist->settings = NULL;
+}
+
+static void
+gst_camera_undistort_dispose (GObject * object)
+{
+  GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (object);
+
+  g_free (undist->settings);
+  undist->settings = NULL;
+
+  G_OBJECT_CLASS (gst_camera_undistort_parent_class)->dispose (object);
+}
+
+
+static void
+gst_camera_undistort_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (object);
+  const char *str;
+
+  switch (prop_id) {
+    case PROP_SHOW_UNDISTORTED:
+      undist->showUndistorted = g_value_get_boolean (value);
+      undist->settingsChanged = true;
+      break;
+    case PROP_ALPHA:
+      undist->alpha = g_value_get_float (value);
+      undist->settingsChanged = true;
+      break;
+    case PROP_CROP:
+      undist->crop = g_value_get_boolean (value);
+      break;
+    case PROP_SETTINGS:
+      if (undist->settings) {
+        g_free (undist->settings);
+        undist->settings = NULL;
+      }
+      str = g_value_get_string (value);
+      if (str)
+          undist->settings = g_strdup (str);
+      undist->settingsChanged = true;
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_camera_undistort_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (object);
+
+  switch (prop_id) {
+    case PROP_SHOW_UNDISTORTED:
+      g_value_set_boolean (value, undist->showUndistorted);
+      break;
+    case PROP_ALPHA:
+      g_value_set_float (value, undist->alpha);
+      break;
+    case PROP_CROP:
+      g_value_set_boolean (value, undist->crop);
+      break;
+    case PROP_SETTINGS:
+      g_value_set_string (value, undist->settings);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+gboolean
+gst_camera_undistort_set_info (GstOpencvVideoFilter * cvfilter,
+    gint in_width, gint in_height,
+    __attribute__((unused)) gint in_depth, __attribute__((unused)) gint in_channels,
+    __attribute__((unused)) gint out_width, __attribute__((unused)) gint out_height,
+    __attribute__((unused)) gint out_depth, __attribute__((unused)) gint out_channels)
+{
+  GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (cvfilter);
+
+  undist->imageSize = cv::Size(in_width, in_height);
+
+  return TRUE;
+}
+
+//static GstMessage *
+//gst_camera_undistort_message_new (GstCameraUndistort * undist, GstBuffer * buf)
+//{
+//  GstBaseTransform *trans = GST_BASE_TRANSFORM_CAST (undist);
+//  GstStructure *s;
+//  GstClockTime running_time, stream_time;
+//
+//  running_time = gst_segment_to_running_time (&trans->segment, GST_FORMAT_TIME,
+//      GST_BUFFER_TIMESTAMP (buf));
+//  stream_time = gst_segment_to_stream_time (&trans->segment, GST_FORMAT_TIME,
+//      GST_BUFFER_TIMESTAMP (buf));
+//
+//  s = gst_structure_new ("cameracalibration",
+//      "timestamp", G_TYPE_UINT64, GST_BUFFER_TIMESTAMP (buf),
+//      "stream-time", G_TYPE_UINT64, stream_time,
+//      "running-time", G_TYPE_UINT64, running_time,
+//      "duration", G_TYPE_UINT64, GST_BUFFER_DURATION (buf), NULL);
+//
+//  return gst_message_new_element (GST_OBJECT (undist), s);
+//}
+
+/*
+ * Performs the camera calibration
+ */
+static GstFlowReturn
+gst_camera_undistort_transform_frame (GstOpencvVideoFilter * cvfilter,
+    G_GNUC_UNUSED GstBuffer * frame, IplImage * img,
+    G_GNUC_UNUSED GstBuffer * outframe, IplImage * outimg)
+{
+  GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (cvfilter);
+
+  camera_undistort_run(undist, img, outimg);
+
+  return GST_FLOW_OK;
+}
+
+/* entry point to initialize the plug-in
+ * initialize the plug-in itself
+ * register the element factories and other features
+ */
+gboolean
+gst_camera_undistort_plugin_init (GstPlugin * plugin)
+{
+  /* debug category for filtering log messages */
+  GST_DEBUG_CATEGORY_INIT (gst_camera_undistort_debug, "cameraundistort",
+      0,
+      "Performs camera undistortion");
+
+  return gst_element_register (plugin, "cameraundistort", GST_RANK_NONE,
+      GST_TYPE_CAMERA_UNDISTORT);
+}
+
+static void
+camera_undistort_run(GstCameraUndistort *undist, IplImage *img, IplImage *outimg)
+{
+    const cv::Mat view = cv::cvarrToMat(img);
+    cv::Mat outview = cv::cvarrToMat(outimg);
+
+    if (undist->settingsChanged) {
+        undist->doUndistort = false;
+        if (undist->showUndistorted && undist->settings) {
+            //qDebug() << undist->settings;
+            if (camera_deserialize_undistort_settings(
+                    undist->settings, undist->cameraMatrix, undist->distCoeffs)) {
+                undist->doUndistort = camera_undistort_init_undistort_rectify_map(undist);
+            }
+        }
+        undist->settingsChanged = false;
+    }
+
+    if (undist->showUndistorted && undist->doUndistort) {
+
+        QElapsedTimer timer;
+        timer.start();
+
+        cv::remap(view, outview, undist->map1, undist->map2, cv::INTER_LINEAR);
+
+        qDebug() << "remap took" << timer.elapsed() << "ms";
+
+        if (undist->crop) {
+          const cv::Scalar CROP_COLOR(0, 255, 0);
+          cv::rectangle(outview, undist->validPixROI, CROP_COLOR);
+        }
+    }
+    else {
+      // FIXME should use passthrough to avoid this copy...
+      view.copyTo(outview);
+    }
+}
+
+
+//    {
+//        Mat view, rview, map1, map2;
+//
+//        if (undist->useFisheye)
+//        {
+//            Mat newCamMat;
+//            fisheye::estimateNewCameraMatrixForUndistortRectify(cameraMatrix, distCoeffs, imageSize,
+//                                                                Matx33d::eye(), newCamMat, 1);
+//            fisheye::initUndistortRectifyMap(cameraMatrix, distCoeffs, Matx33d::eye(), newCamMat, imageSize,
+//                                             CV_16SC2, map1, map2);
+//        }
+//        else
+//        {
+//            initUndistortRectifyMap(
+//                cameraMatrix, distCoeffs, Mat(),
+//                getOptimalNewCameraMatrix(cameraMatrix, distCoeffs, imageSize, 1, imageSize, 0), imageSize,
+//                CV_16SC2, map1, map2);
+//        }
+//    }
+
+
+static gboolean
+camera_undistort_init_undistort_rectify_map(GstCameraUndistort *undist)
+{
+  QElapsedTimer timer;
+  timer.start();
+
+  cv::Size newImageSize;
+  cv::Rect validPixROI;
+  cv::Mat newCameraMatrix = cv::getOptimalNewCameraMatrix(
+        undist->cameraMatrix, undist->distCoeffs, undist->imageSize,
+        undist->alpha, newImageSize, &validPixROI);
+  undist->validPixROI = validPixROI;
+
+  cv::initUndistortRectifyMap(undist->cameraMatrix, undist->distCoeffs, cv::Mat(),
+        newCameraMatrix, undist->imageSize, CV_16SC2, undist->map1, undist->map2);
+
+  qDebug() << "init rectify took" << timer.elapsed() << "ms";
+
+  return TRUE;
+}
+
+/*
+qDebug() << "imageSize" << imageSize.width << imageSize.height;
+qDebug() << "newImageSize" << imageSize.width << imageSize.height;
+qDebug() << "alpha" << undist->alpha;
+qDebug() << "roi" << undist->validPixROI.x << undist->validPixROI.y << undist->validPixROI.width << undist->validPixROI.height;
+
+cv::FileStorage fs1(".xml", cv::FileStorage::WRITE + cv::FileStorage::MEMORY);
+fs1 << "cameraMatrix" << undist->cameraMatrix;
+const std::string buf1 = fs1.releaseAndGetString();
+qDebug() << "cameraMatrix" << QString::fromStdString(buf1);
+
+cv::FileStorage fs2(".xml", cv::FileStorage::WRITE + cv::FileStorage::MEMORY);
+fs2 << "newCameraMatrix" << newCameraMatrix;
+const std::string buf2 = fs2.releaseAndGetString();
+qDebug() << "newCameraMatrix" << QString::fromStdString(buf2);
+
+cv::FileStorage fs3(".xml", cv::FileStorage::WRITE + cv::FileStorage::MEMORY);
+fs3 << "distCoeffs" << undist->distCoeffs;
+const std::string buf3 = fs3.releaseAndGetString();
+qDebug() << "distCoeffs" << QString::fromStdString(buf3);
+*/
+
+static gboolean camera_undistort_calibration_event(GstCameraUndistort *undist, GstEvent *event)
+{
+  g_free (undist->settings);
+
+  if (!gst_camera_event_parse_calibrated(event, &(undist->settings))) {
+      qDebug() << "Failed to parse";
+      return FALSE;
+  }
+
+  undist->settingsChanged = true;
+
+  return TRUE;
+}
+
+static gboolean
+gst_camera_undistort_sink_event (GstBaseTransform *trans, GstEvent *event)
+{
+    GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (trans);
+    const GstStructure *structure = gst_event_get_structure (event);
+
+    if (GST_EVENT_TYPE (event) == GST_EVENT_CUSTOM_BOTH && structure) {
+
+      if (strcmp (gst_structure_get_name (structure), GST_CAMERA_EVENT_CALIBRATED_NAME) == 0) {
+          qDebug() << "GOT CALIBRATION EVENT FROM UPSTREAM";
+          return camera_undistort_calibration_event(undist, event);
+      }
+    }
+
+    return GST_BASE_TRANSFORM_CLASS (gst_camera_undistort_parent_class)->sink_event (trans, event);
+  }
+
+
+static gboolean
+gst_camera_undistort_src_event (GstBaseTransform *trans, GstEvent *event)
+{
+    GstCameraUndistort *undist = GST_CAMERA_UNDISTORT (trans);
+    const GstStructure *structure = gst_event_get_structure (event);
+
+    if (GST_EVENT_TYPE (event) == GST_EVENT_CUSTOM_BOTH && structure) {
+
+      if (strcmp (gst_structure_get_name (structure), GST_CAMERA_EVENT_CALIBRATED_NAME) == 0) {
+          qDebug() << "GOT CALIBRATION EVENT FROM DOWNSTREAM";
+          return camera_undistort_calibration_event(undist, event);
+      }
+    }
+
+    return GST_BASE_TRANSFORM_CLASS (gst_camera_undistort_parent_class)->src_event (trans, event);
+}
+

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstcameraundistort.h

@@ -0,0 +1,109 @@
+/*
+ * GStreamer
+ * Copyright (C) 2005 Thomas Vander Stichele <thomas@apestaart.org>
+ * Copyright (C) 2005 Ronald S. Bultje <rbultje@ronald.bitfreak.net>
+ * Copyright (C) 2008 Michael Sheldon <mike@mikeasoft.com>
+ * Copyright (C) 2011 Stefan Sauer <ensonic@users.sf.net>
+ * Copyright (C) 2011 Robert Jobbagy <jobbagy.robert@gmail.com>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_CAMERA_UNDISTORT_H__
+#define __GST_CAMERA_UNDISTORT_H__
+
+#include <gst/gst.h>
+
+#include <gst/opencv/gstopencvvideofilter.h>
+//#include "gstopencvvideofilter.h"
+
+#include <opencv2/core.hpp>
+
+G_BEGIN_DECLS
+
+#define GST_TYPE_CAMERA_UNDISTORT \
+  (gst_camera_undistort_get_type())
+#define GST_CAMERA_UNDISTORT(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_CAMERA_UNDISTORT,GstCameraUndistort))
+#define GST_CAMERA_UNDISTORT_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_CAMERA_UNDISTORT,GstCameraUndistortClass))
+#define GST_IS_CAMERA_UNDISTORT(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_CAMERA_UNDISTORT))
+#define GST_IS_CAMERA_UNDISTORT_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_CAMERA_UNDISTORT))
+typedef struct _GstCameraUndistort GstCameraUndistort;
+typedef struct _GstCameraUndistortClass GstCameraUndistortClass;
+
+struct _GstCameraUndistort
+{
+  GstOpencvVideoFilter cvfilter;
+  
+  //GRecMutex stream_lock;
+
+  // settings
+  bool showUndistorted;
+  float alpha;
+  bool crop;
+
+  // obscure string containing opencv calibration settings
+  gchar *settings;
+  // opencv calibration settings
+  cv::Mat cameraMatrix, distCoeffs;
+
+  // state
+  bool doUndistort;
+  bool settingsChanged;
+
+  cv::Size imageSize;
+  cv::Mat map1, map2;
+  cv::Rect validPixROI;
+};
+
+struct _GstCameraUndistortClass
+{
+  GstOpencvVideoFilterClass parent_class;
+};
+
+GType gst_camera_undistort_get_type (void);
+
+gboolean gst_camera_undistort_plugin_init (GstPlugin * plugin);
+
+G_END_DECLS
+
+#endif /* __GST_CAMERA_UNDISTORT_H__ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstopencvutils.cpp

@@ -0,0 +1,178 @@
+/* GStreamer
+ * Copyright (C) <2010> Thiago Santos <thiago.sousa.santos@collabora.co.uk>
+ *
+ * gstopencvutils.c: miscellaneous utility functions
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include "gstopencvutils.h"
+#include <opencv2/core/core_c.h>
+
+/*
+The various opencv image containers or headers store the following information:
+- number of channels (usually 1, 3 or 4)
+- depth (8, 16, 32, 64...); all channels have the same depth.
+The channel layout (BGR vs RGB) is not stored...
+
+This gives us the following list of supported image formats:
+  CV_8UC1, CV_8UC2, CV_8UC3, CV_8UC4
+  CV_8SC1, CV_8SC2, CV_8SC3, CV_8SC4
+  CV_16UC1, CV_16UC2, CV_16UC3, CV_16UC4
+  CV_16SC1, CV_16SC2, CV_16SC3, CV_16SC4
+  CV_32SC1, CV_32SC2, CV_32SC3, CV_32SC4
+  CV_32FC1, CV_32FC2, CV_32FC3, CV_32FC4
+  CV_64FC1, CV_64FC2, CV_64FC3, CV_64FC4
+
+Where the first part of the format name is the depth followed by a digit
+representing the number of channels.
+Note that opencv supports more that 4 channels.
+
+The opencv algorithms don't all support all the image types.
+For example findChessboardCorners() supports only 8 bits formats
+(gray scale and color).
+
+And, typically, this algorithm will convert the image to gray scale before
+proceeding. It will do so with something like this:
+   cvtColor(srcImg, destImg, CV_BGR2GRAY);
+
+The conversion will work on any BGR format (BGR, BGRA, BGRx).
+The extra channel(s) will be ignored.
+It will also produce a result for any RGB format.
+The result will be "wrong" to the human eye and might affect some algorithms
+(not findChessboardCorners() afaik...).
+This is due to how RGB gets converted to gray where each color has a
+different weight.
+
+Another example is the 2D rendering API.
+It work with RGB but the colors will be wrong.
+
+Likewise other layouts like xBGR and ABGR formats will probably misbehave
+with most algorithms.
+
+The bad thing is that it is not possible to change the "default" BGR format.
+Safest is to not assume that RGB will work and always convert to BGR.
+
+That said, the current opencv gstreamer elements all accept BGR and RGB caps !
+Some have restrictions but if a format is supported then both BGR and RGB
+layouts will be supported.
+*/
+
+gboolean
+gst_opencv_parse_iplimage_params_from_caps (GstCaps * caps, gint * width,
+    gint * height, gint * ipldepth, gint * channels, GError ** err)
+{
+  GstVideoInfo info;
+  GstVideoFormat format;
+  int cv_type;
+  gchar *caps_str;
+
+  if (!gst_video_info_from_caps (&info, caps)) {
+    caps_str = gst_caps_to_string (caps);
+    GST_ERROR ("Failed to get video info from caps %s", caps_str);
+    g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_NEGOTIATION,
+        "Failed to get video info from caps %s", caps_str);
+    g_free (caps_str);
+    return FALSE;
+  }
+
+  format = GST_VIDEO_INFO_FORMAT (&info);
+  if (!gst_opencv_cv_image_type_from_video_format (format, &cv_type, err)) {
+    return FALSE;
+  }
+
+  *width = GST_VIDEO_INFO_WIDTH (&info);
+  *height = GST_VIDEO_INFO_HEIGHT (&info);
+
+  *ipldepth = cvIplDepth (cv_type);
+  *channels = CV_MAT_CN (cv_type);
+
+  return TRUE;
+}
+
+gboolean
+gst_opencv_cv_image_type_from_video_format (GstVideoFormat format,
+    int * cv_type, GError ** err)
+{
+  const gchar *format_str;
+
+  switch (format) {
+    case GST_VIDEO_FORMAT_GRAY8:
+      *cv_type = CV_8UC1;
+      break;
+    case GST_VIDEO_FORMAT_RGB:
+    case GST_VIDEO_FORMAT_BGR:
+      *cv_type = CV_8UC3;
+      break;
+    case GST_VIDEO_FORMAT_RGBx:
+    case GST_VIDEO_FORMAT_xRGB:
+    case GST_VIDEO_FORMAT_BGRx:
+    case GST_VIDEO_FORMAT_xBGR:
+    case GST_VIDEO_FORMAT_RGBA:
+    case GST_VIDEO_FORMAT_ARGB:
+    case GST_VIDEO_FORMAT_BGRA:
+    case GST_VIDEO_FORMAT_ABGR:
+      *cv_type = CV_8UC4;
+      break;
+    case GST_VIDEO_FORMAT_GRAY16_LE:
+    case GST_VIDEO_FORMAT_GRAY16_BE:
+      *cv_type = CV_16UC1;
+      break;
+    default:
+      format_str = gst_video_format_to_string (format);
+      g_set_error (err, GST_CORE_ERROR, GST_CORE_ERROR_NEGOTIATION,
+          "Unsupported video format %s", format_str);
+      return FALSE;
+  }
+
+  return TRUE;
+}
+
+GstCaps *
+gst_opencv_caps_from_cv_image_type (int cv_type)
+{
+  GstCaps *c = gst_caps_new_empty ();
+  switch (cv_type) {
+    case CV_8UC1:
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("GRAY8")));
+      break;
+    case CV_8UC3:
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("RGB")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("BGR")));
+      break;
+    case CV_8UC4:
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("RGBx")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("xRGB")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("BGRx")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("xBGR")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("RGBA")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("ARGB")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("BGRA")));
+      gst_caps_append (c, gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("ABGR")));
+      break;
+    case CV_16UC1:
+      gst_caps_append (c,
+          gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("GRAY16_LE")));
+      gst_caps_append (c,
+          gst_caps_from_string (GST_VIDEO_CAPS_MAKE ("GRAY16_BE")));
+      break;
+  }
+  return c;
+}

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstopencvutils.h

@@ -0,0 +1,46 @@
+/* GStreamer
+ * Copyright (C) <2010> Thiago Santos <thiago.sousa.santos@collabora.co.uk>
+ *
+ * gstopencvutils.h: miscellaneous utility functions
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_OPENCV_UTILS__
+#define __GST_OPENCV_UTILS__
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <gst/gst.h>
+#include <gst/video/video.h>
+
+G_BEGIN_DECLS
+
+gboolean gst_opencv_parse_iplimage_params_from_caps
+    (GstCaps * caps, gint * width, gint * height, gint * depth,
+    gint * channels, GError ** err);
+
+gboolean
+gst_opencv_cv_image_type_from_video_format (GstVideoFormat format,
+    int * cv_type, GError ** err);
+
+GstCaps * gst_opencv_caps_from_cv_image_type (int cv_type);
+
+G_END_DECLS
+
+#endif /* __GST_OPENCV_UTILS__ */

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstopencvvideofilter.cpp

@@ -0,0 +1,289 @@
+/*
+ * GStreamer
+ * Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+/* TODO opencv can do scaling for some cases */
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif
+
+#include "gstopencvvideofilter.h"
+#include "gstopencvutils.h"
+
+#include <opencv2/core/core_c.h>
+
+GST_DEBUG_CATEGORY_STATIC (gst_opencv_video_filter_debug);
+#define GST_CAT_DEFAULT gst_opencv_video_filter_debug
+
+/* Filter signals and args */
+enum
+{
+  /* FILL ME */
+  LAST_SIGNAL
+};
+
+enum
+{
+  PROP_0
+};
+
+static GstElementClass *parent_class = NULL;
+
+static void gst_opencv_video_filter_class_init (GstOpencvVideoFilterClass *
+    klass);
+static void gst_opencv_video_filter_init (GstOpencvVideoFilter * cv_filter,
+    GstOpencvVideoFilterClass * klass);
+
+static gboolean gst_opencv_video_filter_set_info (GstVideoFilter * vfilter,
+    GstCaps * incaps, GstVideoInfo * in_info,
+    GstCaps * outcaps, GstVideoInfo * out_info);
+static GstFlowReturn gst_opencv_video_filter_transform_frame_ip (
+    GstVideoFilter * vfilter, GstVideoFrame * frame);
+static GstFlowReturn gst_opencv_video_filter_transform_frame (
+    GstVideoFilter * vfilter,
+    GstVideoFrame * inframe, GstVideoFrame * outframe);
+
+static void gst_opencv_video_filter_set_property (GObject * object,
+    guint prop_id, const GValue * value, GParamSpec * pspec);
+static void gst_opencv_video_filter_get_property (GObject * object,
+    guint prop_id, GValue * value, GParamSpec * pspec);
+
+GType
+gst_opencv_video_filter_get_type (void)
+{
+  static volatile gsize opencv_video_filter_type = 0;
+
+  if (g_once_init_enter (&opencv_video_filter_type)) {
+    GType _type;
+    static const GTypeInfo opencv_video_filter_info = {
+      sizeof (GstOpencvVideoFilterClass),
+      NULL,
+      NULL,
+      (GClassInitFunc) gst_opencv_video_filter_class_init,
+      NULL,
+      NULL,
+      sizeof (GstOpencvVideoFilter),
+      0,
+      (GInstanceInitFunc) gst_opencv_video_filter_init,
+    };
+
+    _type = g_type_register_static (GST_TYPE_VIDEO_FILTER,
+        "GstOpencvVideoFilter", &opencv_video_filter_info,
+        G_TYPE_FLAG_ABSTRACT);
+    g_once_init_leave (&opencv_video_filter_type, _type);
+  }
+  return opencv_video_filter_type;
+}
+
+/* Clean up */
+static void
+gst_opencv_video_filter_finalize (GObject * obj)
+{
+  GstOpencvVideoFilter *cv_filter = GST_OPENCV_VIDEO_FILTER (obj);
+
+  if (cv_filter->cvImage)
+    cvReleaseImage (&cv_filter->cvImage);
+  if (cv_filter->out_cvImage)
+    cvReleaseImage (&cv_filter->out_cvImage);
+
+  G_OBJECT_CLASS (parent_class)->finalize (obj);
+}
+
+static void
+gst_opencv_video_filter_class_init (GstOpencvVideoFilterClass * klass)
+{
+  GObjectClass *gobject_class;
+  GstVideoFilterClass *filter_class;
+
+  gobject_class = (GObjectClass *) klass;
+  filter_class = (GstVideoFilterClass *) klass;
+  parent_class = (GstElementClass *) g_type_class_peek_parent (klass);
+
+  GST_DEBUG_CATEGORY_INIT (gst_opencv_video_filter_debug,
+      "opencvvideofilter", 0, "opencvvideofilter element");
+
+  gobject_class->finalize =
+      GST_DEBUG_FUNCPTR (gst_opencv_video_filter_finalize);
+  gobject_class->set_property = gst_opencv_video_filter_set_property;
+  gobject_class->get_property = gst_opencv_video_filter_get_property;
+
+  filter_class->transform_frame = gst_opencv_video_filter_transform_frame;
+  filter_class->transform_frame_ip =
+      gst_opencv_video_filter_transform_frame_ip;
+  filter_class->set_info = gst_opencv_video_filter_set_info;
+}
+
+static void
+gst_opencv_video_filter_init (GstOpencvVideoFilter * cv_filter,
+    GstOpencvVideoFilterClass * klass)
+{
+}
+
+static GstFlowReturn
+gst_opencv_video_filter_transform_frame (GstVideoFilter * vfilter,
+    GstVideoFrame * inframe, GstVideoFrame * outframe)
+{
+  GstOpencvVideoFilter *cv_filter;
+  GstOpencvVideoFilterClass *fclass;
+  GstFlowReturn ret;
+
+  cv_filter = GST_OPENCV_VIDEO_FILTER (vfilter);
+  fclass = GST_OPENCV_VIDEO_FILTER_GET_CLASS (vfilter);
+
+  g_return_val_if_fail (fclass->cv_transform_frame != NULL, GST_FLOW_ERROR);
+  g_return_val_if_fail (cv_filter->cvImage != NULL, GST_FLOW_ERROR);
+  g_return_val_if_fail (cv_filter->out_cvImage != NULL, GST_FLOW_ERROR);
+
+  cv_filter->cvImage->imageData = (char *) inframe->data;
+  cv_filter->out_cvImage->imageData = (char *) outframe->data;
+
+  ret = fclass->cv_transform_frame (cv_filter, inframe, cv_filter->cvImage,
+      outframe, cv_filter->out_cvImage);
+
+  return ret;
+}
+
+static GstFlowReturn
+gst_opencv_video_filter_transform_frame_ip (GstVideoFilter * vfilter,
+    GstVideoFrame * frame)
+{
+  GstOpencvVideoFilter *cv_filter;
+  GstOpencvVideoFilterClass *fclass;
+  GstFlowReturn ret;
+
+  cv_filter = GST_OPENCV_VIDEO_FILTER (vfilter);
+  fclass = GST_OPENCV_VIDEO_FILTER_GET_CLASS (vfilter);
+
+  g_return_val_if_fail (fclass->cv_transform_frame_ip != NULL, GST_FLOW_ERROR);
+  g_return_val_if_fail (cv_filter->cvImage != NULL, GST_FLOW_ERROR);
+
+  cv_filter->cvImage->imageData = (char *) frame->data;
+
+  ret = fclass->cv_transform_frame_ip (cv_filter, frame, cv_filter->cvImage);
+
+  return ret;
+}
+
+static gboolean
+gst_opencv_video_filter_set_info (GstVideoFilter * vfilter, GstCaps * incaps,
+    GstVideoInfo * in_info, GstCaps * outcaps, GstVideoInfo * out_info)
+{
+  GstOpencvVideoFilter *cv_filter = GST_OPENCV_VIDEO_FILTER (vfilter);
+  GstOpencvVideoFilterClass *klass =
+      GST_OPENCV_VIDEO_FILTER_GET_CLASS (cv_filter);
+  gint in_width, in_height;
+  gint in_depth, in_channels;
+  gint out_width, out_height;
+  gint out_depth, out_channels;
+  GError *in_err = NULL;
+  GError *out_err = NULL;
+
+  if (!gst_opencv_parse_iplimage_params_from_caps (incaps, &in_width,
+          &in_height, &in_depth, &in_channels, &in_err)) {
+    GST_WARNING_OBJECT (cv_filter, "Failed to parse input caps: %s",
+        in_err->message);
+    g_error_free (in_err);
+    return FALSE;
+  }
+
+  if (!gst_opencv_parse_iplimage_params_from_caps (outcaps, &out_width,
+          &out_height, &out_depth, &out_channels, &out_err)) {
+    GST_WARNING_OBJECT (cv_filter, "Failed to parse output caps: %s",
+        out_err->message);
+    g_error_free (out_err);
+    return FALSE;
+  }
+
+  if (klass->cv_set_info) {
+    if (!klass->cv_set_info (cv_filter, in_width, in_height, in_depth,
+            in_channels, out_width, out_height, out_depth, out_channels))
+      return FALSE;
+  }
+
+  if (cv_filter->cvImage) {
+    cvReleaseImage (&cv_filter->cvImage);
+  }
+  if (cv_filter->out_cvImage) {
+    cvReleaseImage (&cv_filter->out_cvImage);
+  }
+
+  cv_filter->cvImage =
+      cvCreateImageHeader (cvSize (in_width, in_height), in_depth, in_channels);
+  cv_filter->out_cvImage =
+      cvCreateImageHeader (cvSize (out_width, out_height), out_depth,
+      out_channels);
+
+  gst_base_transform_set_in_place (GST_BASE_TRANSFORM (cv_filter),
+      cv_filter->in_place);
+  return TRUE;
+}
+
+static void
+gst_opencv_video_filter_set_property (GObject * object, guint prop_id,
+    const GValue * value, GParamSpec * pspec)
+{
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+static void
+gst_opencv_video_filter_get_property (GObject * object, guint prop_id,
+    GValue * value, GParamSpec * pspec)
+{
+  switch (prop_id) {
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+  }
+}
+
+void
+gst_opencv_video_filter_set_in_place (GstOpencvVideoFilter * cv_filter,
+    gboolean ip)
+{
+  cv_filter->in_place = ip;
+  gst_base_transform_set_in_place (GST_BASE_TRANSFORM (cv_filter), ip);
+}

ground/gcs/src/libs/gstreamer/plugins/cameracalibration/gstopencvvideofilter.h

@@ -0,0 +1,110 @@
+/*
+ * GStreamer
+ * Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>
+ * 
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ *
+ * Alternatively, the contents of this file may be used under the
+ * GNU Lesser General Public License Version 2.1 (the "LGPL"), in
+ * which case the following provisions apply instead of the ones
+ * mentioned above:
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Library General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Library General Public License for more details.
+ *
+ * You should have received a copy of the GNU Library General Public
+ * License along with this library; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301, USA.
+ */
+
+#ifndef __GST_OPENCV_VIDEO_FILTER_H__
+#define __GST_OPENCV_VIDEO_FILTER_H__
+
+#include <gst/gst.h>
+#include <gst/video/gstvideofilter.h>
+
+G_BEGIN_DECLS
+
+/* forward declare opencv type to avoid exposing them in this API */
+typedef struct _IplImage IplImage;
+
+/* #defines don't like whitespacey bits */
+#define GST_TYPE_OPENCV_VIDEO_FILTER \
+  (gst_opencv_video_filter_get_type())
+#define GST_OPENCV_VIDEO_FILTER(obj) \
+  (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_OPENCV_VIDEO_FILTER,GstOpencvVideoFilter))
+#define GST_OPENCV_VIDEO_FILTER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_OPENCV_VIDEO_FILTER,GstOpencvVideoFilterClass))
+#define GST_IS_OPENCV_VIDEO_FILTER(obj) \
+  (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_OPENCV_VIDEO_FILTER))
+#define GST_IS_OPENCV_VIDEO_FILTER_CLASS(klass) \
+  (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_OPENCV_VIDEO_FILTER))
+#define GST_OPENCV_VIDEO_FILTER_GET_CLASS(obj) \
+  (G_TYPE_INSTANCE_GET_CLASS((obj),GST_TYPE_OPENCV_VIDEO_FILTER,GstOpencvVideoFilterClass))
+#define GST_OPENCV_VIDEO_FILTER_CAST(obj) ((GstOpencvVideoFilter *) (obj))
+
+typedef struct _GstOpencvVideoFilter GstOpencvVideoFilter;
+typedef struct _GstOpencvVideoFilterClass GstOpencvVideoFilterClass;
+
+typedef GstFlowReturn (*GstOpencvVideoFilterTransformIPFunc)
+    (GstOpencvVideoFilter * cvfilter, GstVideoFrame * frame, IplImage * img);
+typedef GstFlowReturn (*GstOpencvVideoFilterTransformFunc)
+    (GstOpencvVideoFilter * cvfilter, GstVideoFrame * frame, IplImage * img,
+    GstVideoFrame * outframe, IplImage * outimg);
+
+typedef gboolean (*GstOpencvVideoFilterSetInfo)
+    (GstOpencvVideoFilter * cv_filter, gint in_width, gint in_height,
+    gint in_depth, gint in_channels, gint out_width, gint out_height,
+    gint out_depth, gint out_channels);
+
+struct _GstOpencvVideoFilter
+{
+  GstVideoFilter videofilter;
+
+  gboolean in_place;
+
+  IplImage *cvImage;
+  IplImage *out_cvImage;
+};
+
+struct _GstOpencvVideoFilterClass
+{
+  GstVideoFilterClass parent_class;
+
+  GstOpencvVideoFilterTransformFunc cv_transform_frame;
+  GstOpencvVideoFilterTransformIPFunc cv_transform_frame_ip;
+
+  GstOpencvVideoFilterSetInfo cv_set_info;
+};
+
+GType gst_opencv_video_filter_get_type (void);
+
+void gst_opencv_video_filter_set_in_place (GstOpencvVideoFilter * cv_filter,
+    gboolean ip);
+
+G_END_DECLS
+#endif /* __GST_OPENCV_VIDEO_FILTER_H__ */

ground/gcs/src/libs/gstreamer/plugins/plugins.pro

@@ -0,0 +1,33 @@
+DEFINES += GST_PLUGIN_BUILD_STATIC
+
+#CONFIG += link_pkgconfig
+PKGCONFIG += gstreamer-base-1.0
+
+do_not_compile {
+    HEADERS += \
+        plugins/cameracalibration/gstopencvutils.h \
+        plugins/cameracalibration/gstopencvvideofilter.hpp
+
+    SOURCES += \
+        plugins/cameracalibration/gstopencvutils.cpp \
+        plugins/cameracalibration/gstopencvvideofilter.cpp \
+}
+
+opencv {
+    # there is no package for gst opencv yet...
+    GSTREAMER_SDK_DIR = $$system(pkg-config --variable=exec_prefix gstreamer-1.0)
+    LIBS += -L$(GSTREAMER_SDK_DIR)/lib/gstreamer-1.0/opencv
+    LIBS += -lgstopencv-1.0
+
+    HEADERS += \
+        plugins/cameracalibration/camerautils.hpp \
+        plugins/cameracalibration/cameraevent.hpp \
+        plugins/cameracalibration/gstcameracalibration.h \
+        plugins/cameracalibration/gstcameraundistort.h
+
+    SOURCES += \
+        plugins/cameracalibration/camerautils.cpp \
+        plugins/cameracalibration/cameraevent.cpp \
+        plugins/cameracalibration/gstcameracalibration.cpp \
+        plugins/cameracalibration/gstcameraundistort.cpp
+}

ground/gcs/src/libs/gstreamer/readme.txt

@@ -0,0 +1,67 @@
+###############################################################################
+# General
+###############################################################################
+
+Add the following line to your build config file:
+    GCS_EXTRA_CONF += gstreamer
+ or run this command
+    make config_append GCS_EXTRA_CONF+=gstreamer
+
+The build config file is at the root of your source directory.
+
+###############################################################################
+# Windows (msys2)
+###############################################################################
+
+i686:
+$ pacman -S mingw-w64-i686-gst-plugins-base mingw-w64-i686-gst-plugins-good mingw-w64-i686-gst-plugins-bad mingw-w64-i686-gst-plugins-ugly  mingw-w64-i686-gst-libav
+
+x86_64:
+$ pacman -S mingw-w64-x86_64-gst-plugins-base mingw-w64-x86_64-gst-plugins-good mingw-w64-x86_64-gst-plugins-bad mingw-w64-x86_64-gst-plugins-ugly mingw-w64-x86_64-gst-libav
+
+###############################################################################
+# Linux
+###############################################################################
+
+Get all the gstreamer libraries.
+
+This might work:
+
+Add the repository ppa:gstreamer-developers/ppa using Synaptic Package Manager or CLI
+> sudo add-apt-repository ppa:gstreamer-developers/ppa
+> sudo apt-get update
+
+Upgrade to latest version of the packages using Synaptic Package Manager or CLI
+> sudo apt-get install gstreamer1.0-tools gstreamer1.0-plugins-base gstreamer1.0-plugins-good gstreamer1.0-plugins-bad gstreamer1.0-plugins-ugly gstreamer1.0-libav
+> sudo apt-get install gstreamer1.0-dev gstreamer-plugins-base1.0-dev
+
+###############################################################################
+# Mac
+###############################################################################
+
+###############################################################################
+# How to find required libraries (for copydata.pro)
+###############################################################################
+
+use gst-inspect with an element or plugin and look at Filename.
+
+$ gst-inspect-1.0.exe ksvideosrc
+Factory Details:
+  Rank                     none (0)
+  Long-name                KsVideoSrc
+  Klass                    Source/Video
+  Description              Stream data from a video capture device through Windows kernel streaming
+  Author                   Ole André Vadla Ravnås <ole.andre.ravnas@tandberg.com>
+Haakon Sporsheim <hakon.sporsheim@tandberg.com>
+Andres Colubri <andres.colubri@gmail.com>
+
+Plugin Details:
+  Name                     winks
+  Description              Windows kernel streaming plugin
+  Filename                 C:\msys64\mingw64\lib\gstreamer-1.0\libgstwinks.dll
+  Version                  1.6.3
+  License                  LGPL
+  Source module            gst-plugins-bad
+  Source release date      2016-01-20
+  Binary package           GStreamer
+  Origin URL               http://gstreamer.net/

ground/gcs/src/libs/gstreamer/videowidget.cpp

@@ -0,0 +1,851 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videowidget.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "videowidget.h"
+
+#include "gst_util.h"
+#include "overlay.h"
+#include "pipelineevent.h"
+// #include "devicemonitor.h"
+
+#include <gst/gst.h>
+#include <gst/video/videooverlay.h>
+
+#include <QtCore>
+#include <QPainter>
+#include <QDebug>
+#include <QRect>
+#include <QTextDocument>
+
+#include <string>
+
+// TODO find a better way and move away from this file
+static Pipeline::State cvt(GstState state);
+static const char *name(Pipeline::State state);
+static ProgressEvent::ProgressType cvt(GstProgressType type);
+
+class GstOverlayImpl : public Overlay {
+public:
+    GstOverlayImpl(GstVideoOverlay *gst_overlay) :
+        gst_overlay(gst_overlay)
+    {}
+    void expose()
+    {
+        if (gst_overlay) {
+            gst_video_overlay_expose(gst_overlay);
+        }
+    }
+private:
+    GstVideoOverlay *gst_overlay;
+};
+
+class BusSyncHandler {
+public:
+    BusSyncHandler(VideoWidget *widget, WId wid) :
+        widget(widget), wId(wid)
+    {}
+    bool handleMessage(GstMessage *msg);
+private:
+    VideoWidget *widget;
+    WId wId;
+};
+
+static GstElement *createPipelineFromDesc(const char *, QString &lastError);
+
+static GstBusSyncReply gst_bus_sync_handler(GstBus *, GstMessage *, BusSyncHandler *);
+
+VideoWidget::VideoWidget(QWidget *parent) :
+    QWidget(parent), pipeline(NULL), overlay(NULL)
+{
+    qDebug() << "VideoWidget::VideoWidget";
+
+    // initialize gstreamer
+    gst::init(NULL, NULL);
+
+    // foreach(Device d, m.devices()) {
+    // qDebug() << d.displayName();
+    // }
+
+    // make the widget native so it gets its own native window id that we will pass to gstreamer
+    setAttribute(Qt::WA_NativeWindow);
+    // setAttribute(Qt::WA_DontCreateNativeAncestors);
+
+    // set black background
+    QPalette pal(palette());
+    pal.setColor(backgroundRole(), Qt::black);
+    setPalette(pal);
+
+    // calling winId() will realize the window if it is not yet realized
+    // so we need to call winId() here and not later from a gstreamer thread...
+    WId wid = winId();
+    qDebug() << "VideoWidget::VideoWidget - video winId :" << (gulong)wid;
+    handler = new BusSyncHandler(this, wid);
+
+    // init widget state (see setOverlay() for more information)
+    // setOverlay(NULL);
+    setAutoFillBackground(true);
+    setAttribute(Qt::WA_OpaquePaintEvent, false);
+    setAttribute(Qt::WA_PaintOnScreen, false);
+
+    // init state
+    lastError = "";
+}
+
+VideoWidget::~VideoWidget()
+{
+    if (pipeline) {
+        dispose();
+    }
+    if (handler) {
+        delete handler;
+        handler = NULL;
+    }
+}
+
+bool VideoWidget::isPlaying()
+{
+    return pipeline && (GST_STATE(pipeline) == GST_STATE_PLAYING);
+}
+
+QString VideoWidget::pipelineDesc()
+{
+    return m_pipelineDesc;
+}
+
+void VideoWidget::setPipelineDesc(QString pipelineDesc)
+{
+    qDebug() << "VideoWidget::setPipelineDesc -" << pipelineDesc;
+    stop();
+    this->m_pipelineDesc = pipelineDesc;
+}
+
+void VideoWidget::start()
+{
+    qDebug() << "VideoWidget::start -" << m_pipelineDesc;
+    init();
+    update();
+    if (pipeline) {
+        gst_element_set_state(GST_ELEMENT(pipeline), GST_STATE_PLAYING);
+    }
+}
+
+void VideoWidget::pause()
+{
+    qDebug() << "VideoWidget::pause -" << m_pipelineDesc;
+    init();
+    update();
+    if (pipeline) {
+        if (GST_STATE(pipeline) == GST_STATE_PAUSED) {
+            gst_element_set_state(GST_ELEMENT(pipeline), GST_STATE_PLAYING);
+        } else if (GST_STATE(pipeline) == GST_STATE_PLAYING) {
+            gst_element_set_state(GST_ELEMENT(pipeline), GST_STATE_PAUSED);
+        }
+    }
+}
+
+void VideoWidget::stop()
+{
+    qDebug() << "VideoWidget::stop -" << m_pipelineDesc;
+    if (pipeline) {
+        dispose();
+    } else {
+        // emit fake state change event. this is needed by the UI...
+        emit stateChanged(Pipeline::Null, Pipeline::Null, Pipeline::VoidPending);
+    }
+    update();
+}
+
+void VideoWidget::init()
+{
+    if (pipeline) {
+        // if pipeline is already created, reset some state and return
+        qDebug() << "VideoWidget::init - reseting pipeline state :" << m_pipelineDesc;
+        lastError = "";
+        return;
+    }
+
+    // reset state
+    lastError = "";
+
+    // create pipeline
+    qDebug() << "VideoWidget::init - initializing pipeline :" << m_pipelineDesc;
+    pipeline = createPipelineFromDesc(m_pipelineDesc.toStdString().c_str(), lastError);
+    if (pipeline) {
+        gst_pipeline_set_auto_flush_bus(GST_PIPELINE(pipeline), true);
+
+        // register bus synchronous handler
+        GstBus *bus = gst_pipeline_get_bus(GST_PIPELINE(pipeline));
+        gst_bus_set_sync_handler(bus, (GstBusSyncHandler)gst_bus_sync_handler, handler, NULL);
+        gst_object_unref(bus);
+    } else {
+        // emit fake state change event. this is needed by the UI...
+        emit stateChanged(Pipeline::Null, Pipeline::Null, Pipeline::VoidPending);
+    }
+}
+
+void VideoWidget::dispose()
+{
+    qDebug() << "VideoWidget::dispose -" << m_pipelineDesc;
+
+    setOverlay(NULL);
+
+    if (pipeline) {
+        gst_element_set_state(pipeline, GST_STATE_NULL);
+        gst_object_unref(pipeline);
+        pipeline = NULL;
+    }
+}
+
+void VideoWidget::paintEvent(QPaintEvent *event)
+{
+    if (overlay) {
+        overlay->expose();
+    } else {
+        QWidget::paintEvent(event);
+        paintStatus(event);
+    }
+}
+
+void VideoWidget::paintStatus(QPaintEvent *event)
+{
+    Q_UNUSED(event);
+
+    QTextDocument doc;
+    doc.setDefaultStyleSheet("* { color:red; }");
+
+    QString html     = "<p align=center><font size=+2>" + getStatusMessage() + "</font></p>";
+
+    QRect widgetRect = QWidget::rect();
+    int x      = 0;
+    int w      = widgetRect.width();
+    int hh     = widgetRect.height() / 4;
+    int y      = (widgetRect.height() - hh) / 2;
+    int h      = widgetRect.height() - y;
+    QRect rect = QRect(x, y, w, h);
+
+    doc.setHtml(html);
+    doc.setTextWidth(rect.width());
+
+    QPainter painter(this);
+    painter.save();
+    painter.translate(rect.topLeft());
+    doc.drawContents(&painter, rect.translated(-rect.topLeft()));
+    painter.restore();
+    // painter.drawRect(rect);
+
+    // QBrush brush( Qt::yellow );
+    // painter.setBrush( brush );		// set the yellow brush
+    // painter.setPen( Qt::NoPen );		// do not draw outline
+    // painter.drawRect(0, 0, width(), height());	// draw filled rectangle
+    // painter.end();
+
+    // QFont font = QApplication::font();
+    // font.setPixelSize( rect.height() );
+    // painter.setFont( font );
+}
+
+QString VideoWidget::getStatus()
+{
+    if (!lastError.isEmpty()) {
+        return "ERROR";
+    } else if (!pipeline && m_pipelineDesc.isEmpty()) {
+        return "NO PIPELINE";
+    }
+    return "";
+}
+
+QString VideoWidget::getStatusMessage()
+{
+    if (!lastError.isEmpty()) {
+        return lastError;
+    } else if (!pipeline && m_pipelineDesc.isEmpty()) {
+        return "No pipeline";
+    }
+    return "";
+}
+
+void VideoWidget::mouseDoubleClickEvent(QMouseEvent *event)
+{
+    Q_UNUSED(event);
+}
+
+void VideoWidget::resizeEvent(QResizeEvent *event)
+{
+    if (overlay) {
+        overlay->expose();
+    } else {
+        QWidget::resizeEvent(event);
+    }
+}
+
+QPaintEngine *VideoWidget::paintEngine() const
+{
+    // bypass double buffering, see setOverlay() for explanation
+    return overlay ? NULL : QWidget::paintEngine();
+}
+
+static Pipeline::State cvt(GstState state)
+{
+    switch (state) {
+    case GST_STATE_VOID_PENDING:
+        return Pipeline::VoidPending;
+
+    case GST_STATE_NULL:
+        return Pipeline::Null;
+
+    case GST_STATE_READY:
+        return Pipeline::Ready;
+
+    case GST_STATE_PAUSED:
+        return Pipeline::Paused;
+
+    case GST_STATE_PLAYING:
+        return Pipeline::Playing;
+    }
+    return Pipeline::Null;
+}
+
+static const char *name(Pipeline::State state)
+{
+    switch (state) {
+    case Pipeline::VoidPending:
+        return "VoidPending";
+
+    case Pipeline::Null:
+        return "Null";
+
+    case Pipeline::Ready:
+        return "Ready";
+
+    case Pipeline::Paused:
+        return "Paused";
+
+    case Pipeline::Playing:
+        return "Playing";
+    }
+    return "<unknown>";
+}
+
+// static StreamStatusEvent::StreamStatusType cvt(GstStreamStatusType type)
+// {
+// switch (type) {
+// case GST_STREAM_STATUS_TYPE_CREATE:
+// return StreamStatusEvent::Create;
+//
+// case GST_STREAM_STATUS_TYPE_ENTER:
+// return StreamStatusEvent::Enter;
+//
+// case GST_STREAM_STATUS_TYPE_LEAVE:
+// return StreamStatusEvent::Leave;
+//
+// case GST_STREAM_STATUS_TYPE_DESTROY:
+// return StreamStatusEvent::Destroy;
+//
+// case GST_STREAM_STATUS_TYPE_START:
+// return StreamStatusEvent::Start;
+//
+// case GST_STREAM_STATUS_TYPE_PAUSE:
+// return StreamStatusEvent::Pause;
+//
+// case GST_STREAM_STATUS_TYPE_STOP:
+// return StreamStatusEvent::Stop;
+// }
+// return StreamStatusEvent::Null;
+// }
+
+static ProgressEvent::ProgressType cvt(GstProgressType type)
+{
+    switch (type) {
+    case GST_PROGRESS_TYPE_START:
+        return ProgressEvent::Start;
+
+    case GST_PROGRESS_TYPE_CONTINUE:
+        return ProgressEvent::Continue;
+
+    case GST_PROGRESS_TYPE_COMPLETE:
+        return ProgressEvent::Complete;
+
+    case GST_PROGRESS_TYPE_CANCELED:
+        return ProgressEvent::Cancelled;
+
+    case GST_PROGRESS_TYPE_ERROR:
+        return ProgressEvent::Error;
+    }
+    return ProgressEvent::Error;
+}
+
+bool VideoWidget::event(QEvent *event)
+{
+    if (event->type() == PipelineEvent::PrepareWindowId) {
+        PrepareWindowIdEvent *pe = static_cast<PrepareWindowIdEvent *>(event);
+        // we take ownership of the overlay object
+        setOverlay(pe->getOverlay());
+        QString msg = QString("PrepareWindowId: element %0 prepare window id").arg(pe->src);
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::StateChange) {
+        StateChangedEvent *sce = static_cast<StateChangedEvent *>(event);
+        QString msg = QString("StateChange: element %0 changed state from %1 to %2")
+                      .arg(sce->src).arg(name(sce->getOldState())).arg(name(sce->getNewState()));
+        emitEventMessage(msg);
+        emit stateChanged(sce->getOldState(), sce->getNewState(), sce->getPendingState());
+
+        if (sce->getNewState() == Pipeline::Playing) {
+            if (pipeline) {
+                toDotFile("pipeline");
+            }
+        }
+
+        return true;
+    } else if (event->type() == PipelineEvent::StreamStatus) {
+        StreamStatusEvent *sse = static_cast<StreamStatusEvent *>(event);
+        QString msg = QString("StreamStatus: %0 %1 (%2)").arg(sse->src).arg(sse->getStatusName()).arg(sse->getOwner());
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::NewClock) {
+        NewClockEvent *nce = static_cast<NewClockEvent *>(event);
+        QString msg = QString("NewClock : element %0 has new clock %1").arg(nce->src).arg(nce->getName());
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::ClockProvide) {
+        ClockProvideEvent *cpe = static_cast<ClockProvideEvent *>(event);
+        QString msg = QString("ClockProvide: element %0 clock provide %1 ready=%2").arg(cpe->src).arg(cpe->getName()).arg(cpe->isReady());
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::ClockLost) {
+        ClockLostEvent *cle = static_cast<ClockLostEvent *>(event);
+        QString msg = QString("ClockLost: element %0 lost clock %1").arg(cle->src).arg(cle->getName());
+        emitEventMessage(msg);
+
+        // PRINT ("Clock lost, selecting a new one\n");
+        // gst_element_set_state (pipeline, GST_STATE_PAUSED);
+        // gst_element_set_state (pipeline, GST_STATE_PLAYING);
+
+        return true;
+    } else if (event->type() == PipelineEvent::Progress) {
+        ProgressEvent *pe = static_cast<ProgressEvent *>(event);
+        QString msg = QString("Progress: element %0 sent progress event: %1 %2 (%3)").arg(pe->src).arg(pe->getProgressType()).arg(
+            pe->getCode()).arg(pe->getText());
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::Latency) {
+        LatencyEvent *le = static_cast<LatencyEvent *>(event);
+        QString msg  = QString("Latency: element %0 sent latency event").arg(le->src);
+        emitEventMessage(msg);
+
+        bool success = gst_bin_recalculate_latency(GST_BIN(pipeline));
+        if (!success) {
+            qWarning() << "Failed to recalculate latency";
+        }
+
+        return true;
+    } else if (event->type() == PipelineEvent::Qos) {
+        QosEvent *qe = static_cast<QosEvent *>(event);
+        QString msg  = QString("Qos: element %0 sent QOS event: %1 %2 %3").arg(qe->src).arg(qe->getData().timestamps()).arg(
+            qe->getData().values()).arg(qe->getData().stats());
+        emitEventMessage(msg);
+
+        if (pipeline) {
+            toDotFile("pipeline_qos");
+        }
+
+        return true;
+    } else if (event->type() == PipelineEvent::Eos) {
+        QString msg = QString("Eos: element %0 sent EOS event");
+        emitEventMessage(msg);
+
+        if (pipeline) {
+            toDotFile("pipeline_eos");
+        }
+
+        return true;
+    } else if (event->type() == PipelineEvent::Error) {
+        ErrorEvent *ee = static_cast<ErrorEvent *>(event);
+        QString msg    = QString("Error: element %0 sent error event: %1 (%2)").arg(ee->src).arg(ee->getMessage()).arg(
+            ee->getDebug());
+        emitEventMessage(msg);
+        if (lastError.isEmpty()) {
+            // remember first error only (usually the most useful)
+            lastError = QString("Pipeline error: %0").arg(ee->getMessage());
+            // stop pipeline...
+            stop();
+        } else {
+            // TODO record subsequent errors separately
+        }
+        return true;
+    } else if (event->type() == PipelineEvent::Warning) {
+        WarningEvent *we = static_cast<WarningEvent *>(event);
+        QString msg = QString("Warning: element %0 sent warning event: %1 (%2)").arg(we->src).arg(we->getMessage()).arg(
+            we->getDebug());
+        emitEventMessage(msg);
+        return true;
+    } else if (event->type() == PipelineEvent::Info) {
+        InfoEvent *ie = static_cast<InfoEvent *>(event);
+        QString msg   = QString("Info: element %0 sent info event: %1 (%2)").arg(ie->src).arg(ie->getMessage()).arg(
+            ie->getDebug());
+        emitEventMessage(msg);
+        return true;
+    }
+    return QWidget::event(event);
+}
+
+void VideoWidget::emitEventMessage(QString msg)
+{
+    // qDebug() << "VideoWidget::event -" << msg;
+    emit message(msg);
+}
+
+void VideoWidget::setOverlay(Overlay *overlay)
+{
+    if (this->overlay != overlay) {
+        Overlay *oldOverlay = this->overlay;
+        this->overlay = overlay;
+        if (oldOverlay) {
+            delete oldOverlay;
+        }
+    }
+
+    bool hasOverlay = overlay ? true : false;
+
+    setAutoFillBackground(!hasOverlay);
+
+    // disable background painting to avoid flickering when resizing
+    setAttribute(Qt::WA_OpaquePaintEvent, hasOverlay);
+    // setAttribute(Qt::WA_NoSystemBackground, hasOverlay); // not sure it is needed
+
+    // disable double buffering to avoid flickering when resizing
+    // for this to work we also need to override paintEngine() and make it return NULL.
+    // see http://qt-project.org/faq/answer/how_does_qtwa_paintonscreen_relate_to_the_backing_store_widget_composition_
+    // drawback is that this widget won't participate in composition...
+    setAttribute(Qt::WA_PaintOnScreen, hasOverlay);
+}
+
+
+void VideoWidget::toDotFile(QString name)
+{
+    if (!pipeline) {
+        return;
+    }
+    GST_DEBUG_BIN_TO_DOT_FILE_WITH_TS(GST_BIN(pipeline), GST_DEBUG_GRAPH_SHOW_VERBOSE, name.toStdString().c_str());
+}
+
+static GstElement *createPipelineFromDesc(const char *desc, QString &lastError)
+{
+    qDebug() << "VideoWidget::createPipelineFromDesc - creating pipeline :" << desc;
+    GError *error = NULL;
+    GstElement *pipeline = gst_parse_launch_full(desc, NULL, GST_PARSE_FLAG_FATAL_ERRORS, &error);
+    if (!pipeline) {
+        if (error) {
+            // no pipeline and error...
+            // report error to user
+            QString msg = QString("Failed to create pipeline: %0").arg(error->message);
+            qCritical() << "VideoWidget::createPipelineFromDesc -" << msg;
+            lastError = msg;
+        } else {
+            // no pipeline and no error...
+            // report generic error
+            QString msg = QString("Failed to create pipeline (no error reported!)");
+            qCritical() << "VideoWidget::createPipelineFromDesc -" << msg;
+            lastError = msg;
+        }
+    } else if (error) {
+        // pipeline and error...
+        // report error to user?
+        // warning?
+        QString msg = QString("Created pipeline with error: %0").arg(error->message);
+        qWarning() << "VideoWidget::createPipelineFromDesc -" << msg;
+    } else {
+        // qDebug() << gst_bin_get_by_name(GST_BIN(pipeline), "videotestsrc0");
+    }
+    if (error) {
+        g_error_free(error);
+    }
+    return pipeline;
+}
+
+bool BusSyncHandler::handleMessage(GstMessage *message)
+{
+    // this method is called by gstreamer as a callback
+    // and as such is not necessarily called on the QT event handling thread
+
+    bool handled = false;
+
+    switch (GST_MESSAGE_TYPE(message)) {
+    case GST_MESSAGE_ELEMENT:
+    {
+        if (gst_is_video_overlay_prepare_window_handle_message(message)) {
+            qDebug().noquote() << QString("VideoWidget::handleMessage - element %0 prepare window with id #%1").arg(GST_OBJECT_NAME(message->src)).arg((gulong)wId);
+            // prepare-xwindow-id must be handled synchronously in order to have gstreamer use our window
+            GstVideoOverlay *gst_video_overlay = GST_VIDEO_OVERLAY(GST_MESSAGE_SRC(message));
+            gst_video_overlay_set_window_handle(gst_video_overlay, (gulong)wId);
+            // and now post event asynchronously
+            Overlay *overlay = new GstOverlayImpl(gst_video_overlay);
+            QString src(GST_OBJECT_NAME(message->src));
+            QCoreApplication::postEvent(widget, new PrepareWindowIdEvent(src, overlay));
+            // notify that the message was handled
+            handled = true;
+        }
+        break;
+    }
+    case GST_MESSAGE_STATE_CHANGED:
+    {
+        if (GST_IS_PIPELINE(message->src)) {
+            GstState old_state, new_state, pending_state;
+            gst_message_parse_state_changed(message, &old_state, &new_state, &pending_state);
+
+            QString src(GST_OBJECT_NAME(message->src));
+            QCoreApplication::postEvent(widget, new StateChangedEvent(src, cvt(old_state), cvt(new_state), cvt(pending_state)));
+        }
+        break;
+    }
+    case GST_MESSAGE_STREAM_STATUS:
+    {
+        GstStreamStatusType type;
+        GstElement *owner;
+        gst_message_parse_stream_status(message, &type, &owner);
+
+        // QString src(GST_OBJECT_NAME(message->src));
+        // QString name(GST_OBJECT_NAME(owner));
+        // QCoreApplication::postEvent(widget, new StreamStatusEvent(src, cvt(type), name));
+        break;
+    }
+    case GST_MESSAGE_NEW_CLOCK:
+    {
+        if (GST_IS_PIPELINE(message->src)) {
+            GstClock *clock;
+
+            gst_message_parse_new_clock(message, &clock);
+
+            QString src(GST_OBJECT_NAME(message->src));
+            QString name(GST_OBJECT_NAME(clock));
+            QCoreApplication::postEvent(widget, new NewClockEvent(src, name));
+        }
+        break;
+    }
+    case GST_MESSAGE_CLOCK_PROVIDE:
+    {
+        if (GST_IS_PIPELINE(message->src)) {
+            GstClock *clock;
+            gboolean ready;
+
+            gst_message_parse_clock_provide(message, &clock, &ready);
+
+            QString src(GST_OBJECT_NAME(message->src));
+            QString name(GST_OBJECT_NAME(clock));
+            QCoreApplication::postEvent(widget, new ClockProvideEvent(src, name, ready));
+        }
+        break;
+    }
+    case GST_MESSAGE_CLOCK_LOST:
+    {
+        if (GST_IS_PIPELINE(message->src)) {
+            GstClock *clock;
+
+            gst_message_parse_clock_lost(message, &clock);
+
+            QString src(GST_OBJECT_NAME(message->src));
+            QString name(GST_OBJECT_NAME(clock));
+            QCoreApplication::postEvent(widget, new ClockLostEvent(src, name));
+        }
+        break;
+    }
+    case GST_MESSAGE_PROGRESS:
+    {
+        GstProgressType type;
+        gchar *code;
+        gchar *text;
+        gst_message_parse_progress(message, &type, &code, &text);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new ProgressEvent(src, cvt(type), QString(code), QString(text)));
+
+        g_free(code);
+        g_free(text);
+        break;
+    }
+    case GST_MESSAGE_SEGMENT_START:
+    {
+        GstFormat format;
+        gint64 position;
+        gst_message_parse_segment_start(message, &format, &position);
+
+        // QString src(GST_OBJECT_NAME(message->src));
+        // QCoreApplication::postEvent(widget, new InfoEvent(src, QString("Segment start %0").arg(position), ""));
+
+        break;
+    }
+    case GST_MESSAGE_SEGMENT_DONE:
+    {
+        GstFormat format;
+        gint64 position;
+        gst_message_parse_segment_done(message, &format, &position);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new InfoEvent(src, QString("Segment done %0").arg(position), ""));
+
+        break;
+    }
+    case GST_MESSAGE_LATENCY:
+    {
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new LatencyEvent(src));
+        break;
+    }
+    case GST_MESSAGE_BUFFERING:
+    {
+        gint percent;
+        gst_message_parse_buffering(message, &percent);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new InfoEvent(src, QString("%0%").arg(percent), ""));
+
+        break;
+    }
+    case GST_MESSAGE_QOS:
+    {
+        QosData data;
+        gboolean live;
+        guint64 running_time;
+        guint64 stream_time;
+        guint64 timestamp;
+        guint64 duration;
+        gst_message_parse_qos(message, &live, &running_time, &stream_time, &timestamp, &duration);
+        data.live = (live == true);
+        data.running_time = running_time;
+        data.stream_time  = stream_time;
+        data.timestamp    = timestamp;
+        data.duration     = duration;
+
+        gint64 jitter;
+        gdouble proportion;
+        gint quality;
+        gst_message_parse_qos_values(message, &jitter, &proportion, &quality);
+        data.jitter     = jitter;
+        data.proportion = proportion;
+        data.quality    = quality;
+
+        guint64 processed;
+        guint64 dropped;
+        gst_message_parse_qos_stats(message, NULL, &processed, &dropped);
+        data.processed = processed;
+        data.dropped   = dropped;
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new QosEvent(src, data));
+
+        break;
+    }
+    case GST_MESSAGE_EOS:
+    {
+        /* end-of-stream */
+        // g_main_loop_quit (loop);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new EosEvent(src));
+
+        break;
+    }
+    case GST_MESSAGE_ERROR:
+    {
+        GError *err;
+        gchar *debug;
+        gst_message_parse_error(message, &err, &debug);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new ErrorEvent(src, QString(err->message), QString(debug)));
+
+        g_error_free(err);
+        g_free(debug);
+        break;
+    }
+    case GST_MESSAGE_WARNING:
+    {
+        GError *err;
+        gchar *debug;
+        gst_message_parse_warning(message, &err, &debug);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new WarningEvent(src, QString(err->message), QString(debug)));
+
+        g_error_free(err);
+        g_free(debug);
+        break;
+    }
+    case GST_MESSAGE_INFO:
+    {
+        GError *err;
+        gchar *debug;
+        gst_message_parse_info(message, &err, &debug);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new InfoEvent(src, QString(err->message), QString(debug)));
+
+        g_error_free(err);
+        g_free(debug);
+        break;
+    }
+    case GST_MESSAGE_TAG:
+    {
+        GstTagList *tags = NULL;
+        gst_message_parse_tag(message, &tags);
+
+        // QString src(GST_OBJECT_NAME(message->src));
+        // QCoreApplication::postEvent(widget, new InfoEvent(src, QString(err->message), QString(debug)));
+
+        gst_tag_list_unref(tags);
+        break;
+    }
+    default:
+    {
+        // const GstStructure *s;
+        // const gchar *name;
+        //
+        // s = gst_message_get_structure (message);
+        //
+        // name = gst_structure_get_name(s);
+
+        QString src(GST_OBJECT_NAME(message->src));
+        QCoreApplication::postEvent(widget, new InfoEvent(src, "Unhandled message", QString("%0").arg(GST_MESSAGE_TYPE_NAME(message))));
+
+        break;
+    }
+    }
+    return handled;
+}
+
+static GstBusSyncReply gst_bus_sync_handler(GstBus *bus, GstMessage *message, BusSyncHandler *handler)
+{
+    Q_UNUSED(bus);
+    // qDebug().noquote() << QString("VideoWidget::gst_bus_sync_handler (%0) : %1 : %2")
+    // .arg((long)QThread::currentThreadId())
+    // .arg(GST_MESSAGE_SRC_NAME(message))
+    // .arg(GST_MESSAGE_TYPE_NAME(message));
+    if (handler->handleMessage(message)) {
+        gst_message_unref(message);
+        return GST_BUS_DROP;
+    }
+    return GST_BUS_PASS;
+}

ground/gcs/src/libs/gstreamer/videowidget.h

@@ -0,0 +1,94 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetwidget.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @brief
+ * @see        The GNU Public License (GPL) Version 3
+ * @defgroup
+ * @{
+ *
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#ifndef VIDEOWIDGET_H_
+#define VIDEOWIDGET_H_
+
+#include "gst_global.h"
+#include "pipeline.h"
+#include "overlay.h"
+
+#include <QWidget>
+#include <QResizeEvent>
+#include <QPaintEvent>
+#include <QMouseEvent>
+
+typedef struct _GstElement GstElement;
+
+class BusSyncHandler;
+
+class GST_LIB_EXPORT VideoWidget : public QWidget {
+    Q_OBJECT
+
+public:
+    VideoWidget(QWidget *parent = 0);
+    ~VideoWidget();
+
+    QString pipelineDesc();
+    void setPipelineDesc(QString pipelineDesc);
+    bool isPlaying();
+
+public slots:
+    void start();
+    void pause();
+    void stop();
+
+signals:
+    void message(QString);
+    void stateChanged(Pipeline::State oldState, Pipeline::State newState, Pipeline::State pendingState);
+
+protected:
+    QString getStatus();
+    QString getStatusMessage();
+    void paintStatus(QPaintEvent *);
+    // QWidget overrides
+    void paintEvent(QPaintEvent *);
+    void resizeEvent(QResizeEvent *);
+    void mouseDoubleClickEvent(QMouseEvent *);
+
+private:
+    void init();
+    void dispose();
+    void setOverlay(Overlay *);
+
+    void emitEventMessage(QString msg);
+
+    void toDotFile(QString name);
+
+    // QWidget overrides
+    bool event(QEvent *);
+    QPaintEngine *paintEngine() const;
+
+    QString m_pipelineDesc;
+    QString lastError;
+    GstElement *pipeline;
+    Overlay *overlay;
+    BusSyncHandler *handler;
+
+    // DeviceMonitor m;
+};
+
+#endif /* VIDEOWIDGET_H_ */

ground/gcs/src/libs/libs.pro

@@ -11,6 +11,6 @@ SUBDIRS = \
     qwt \
     sdlgamepad
 
-osg {
+gstreamer:SUBDIRS += gstreamer
-    SUBDIRS += osgearth
+
-}
+osg:SUBDIRS += osgearth

ground/gcs/src/plugins/plugins.pro

@@ -231,6 +231,13 @@ plugin_flightlog.depends += plugin_uavobjects
 plugin_flightlog.depends += plugin_uavtalk
 SUBDIRS += plugin_flightlog
 
+# Video plugin
+gstreamer {
+    plugin_video.subdir = video
+    plugin_video.depends = plugin_coreplugin
+    SUBDIRS += plugin_video
+}
+
 # Usage Tracker plugin
 plugin_usagetracker.subdir = usagetracker
 plugin_usagetracker.depends = plugin_coreplugin

ground/gcs/src/plugins/video/VideoGadget.pluginspec

@@ -0,0 +1,10 @@
+<plugin name="VideoGadget" version="1.0.0" compatVersion="1.0.0">
+    <vendor>The LibrePilot Project</vendor>
+    <copyright>(C) 2017 The LibrePilot Project</copyright>
+    <license>The GNU Public License (GPL) Version 3</license>
+    <description>A video gadget</description>
+    <url>http://www.librepilot.org</url>
+    <dependencyList>
+        <dependency name="Core" version="1.0.0"/>
+    </dependencyList>
+</plugin>    

ground/gcs/src/plugins/video/helpdialog.cpp

@@ -0,0 +1,86 @@
+/**
+ ******************************************************************************
+ *
+ * @file       helpdialog.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "helpdialog.h"
+
+#include "ui_helpdialog.h"
+
+#include <QDebug>
+#include <QPushButton>
+
+HelpDialog::HelpDialog(QWidget *parent, const QString &elementId)
+    : QDialog(parent),
+    m_windowWidth(0),
+    m_windowHeight(0)
+{
+    Q_UNUSED(elementId)
+
+    m_helpDialog = new Ui_HelpDialog();
+    m_helpDialog->setupUi(this);
+
+    setWindowTitle(tr("GStreamer Help"));
+
+    if (m_windowWidth > 0 && m_windowHeight > 0) {
+        resize(m_windowWidth, m_windowHeight);
+    }
+
+    m_helpDialog->buttonBox->button(QDialogButtonBox::Close)->setDefault(true);
+
+    connect(m_helpDialog->buttonBox->button(QDialogButtonBox::Close), SIGNAL(clicked()), this, SLOT(close()));
+
+    m_helpDialog->splitter->setCollapsible(0, false);
+    m_helpDialog->splitter->setCollapsible(1, false);
+
+    connect(m_helpDialog->elementListWidget, SIGNAL(currentItemChanged(QListWidgetItem *, QListWidgetItem *)),
+            this, SLOT(pageSelected()));
+
+    QList<QString> plugins; // = gst::pluginList();
+
+// foreach(QString pluginName, plugins) {
+// new QListWidgetItem(pluginName, m_helpDialog->elementListWidget);
+// }
+}
+
+HelpDialog::~HelpDialog()
+{
+// foreach(QString category, m_categoryItemsMap.keys()) {
+// QList<QTreeWidgetItem *> *categoryItemList = m_categoryItemsMap.value(category);
+// delete categoryItemList;
+// }
+}
+
+void HelpDialog::itemSelected()
+{}
+
+void HelpDialog::close()
+{}
+
+bool HelpDialog::execDialog()
+{
+    exec();
+    return true;
+}

ground/gcs/src/plugins/video/helpdialog.h

@@ -0,0 +1,60 @@
+/**
+ ******************************************************************************
+ *
+ * @file       helpdialog.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef HELPDIALOG_H
+#define HELPDIALOG_H
+
+#include <QDialog>
+#include <QList>
+
+class Ui_HelpDialog;
+
+class HelpDialog : public QDialog {
+    Q_OBJECT
+
+public:
+    HelpDialog(QWidget *parent, const QString &initialElement = QString());
+    ~HelpDialog();
+
+    // Run the dialog and return true if 'Ok' was choosen or 'Apply' was invoked
+    // at least once
+    bool execDialog();
+
+private slots:
+    void itemSelected();
+    void close();
+
+private:
+    Ui_HelpDialog *m_helpDialog;
+
+    QList<QString> m_elements;
+
+    int m_windowWidth;
+    int m_windowHeight;
+};
+
+#endif // HELPDIALOG_H

ground/gcs/src/plugins/video/helpdialog.ui

@@ -0,0 +1,82 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>HelpDialog</class>
+ <widget class="QDialog" name="HelpDialog">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>697</width>
+    <height>476</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Options</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QSplitter" name="splitter">
+     <property name="orientation">
+      <enum>Qt::Vertical</enum>
+     </property>
+     <widget class="QWidget" name="layoutWidget">
+      <layout class="QHBoxLayout" name="horizontalLayout">
+       <item>
+        <widget class="QListWidget" name="pluginListWidget"/>
+       </item>
+       <item>
+        <widget class="QListWidget" name="elementListWidget"/>
+       </item>
+      </layout>
+     </widget>
+     <widget class="QTextBrowser" name="textBrowser"/>
+    </widget>
+   </item>
+   <item>
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="orientation">
+      <enum>Qt::Horizontal</enum>
+     </property>
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Close</set>
+     </property>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>accepted()</signal>
+   <receiver>HelpDialog</receiver>
+   <slot>accept()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>297</x>
+     <y>361</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>297</x>
+     <y>193</y>
+    </hint>
+   </hints>
+  </connection>
+  <connection>
+   <sender>buttonBox</sender>
+   <signal>rejected()</signal>
+   <receiver>HelpDialog</receiver>
+   <slot>reject()</slot>
+   <hints>
+    <hint type="sourcelabel">
+     <x>297</x>
+     <y>361</y>
+    </hint>
+    <hint type="destinationlabel">
+     <x>297</x>
+     <y>193</y>
+    </hint>
+   </hints>
+  </connection>
+ </connections>
+</ui>

ground/gcs/src/plugins/video/video.pro

@@ -0,0 +1,37 @@
+TEMPLATE = lib 
+TARGET = VideoGadget
+
+QT += widgets
+
+include(../../plugin.pri)
+include(../../plugins/coreplugin/coreplugin.pri)
+include(../../libs/gstreamer/gstreamer.pri)
+
+HEADERS += \
+    helpdialog.h \
+    videoplugin.h \
+    videogadgetconfiguration.h \
+    videogadget.h \
+    videogadgetwidget.h \
+    videogadgetfactory.h \
+    videogadgetoptionspage.h
+
+SOURCES += \
+    helpdialog.cpp \
+    videoplugin.cpp \
+    videogadgetconfiguration.cpp \
+    videogadget.cpp \
+    videogadgetfactory.cpp \
+    videogadgetwidget.cpp \
+    videogadgetoptionspage.cpp
+
+OTHER_FILES += \
+    VideoGadget.pluginspec
+
+FORMS += \
+    helpdialog.ui \
+    video.ui \
+    videooptionspage.ui
+
+RESOURCES += \
+    video.qrc

ground/gcs/src/plugins/video/video.qrc

@@ -0,0 +1,33 @@
+<RCC>
+    <qresource prefix="/video" >
+        <file>resources/22x22/media-eject.png</file>
+        <file>resources/32x32/media-eject.png</file>
+
+        <file>resources/22x22/media-playback-pause.png</file>
+        <file>resources/32x32/media-playback-pause.png</file>
+
+        <file>resources/22x22/media-playback-start.png</file>
+        <file>resources/32x32/media-playback-start.png</file>
+
+        <file>resources/22x22/media-playback-stop.png</file>
+        <file>resources/32x32/media-playback-stop.png</file>
+
+        <file>resources/22x22/media-record.png</file>
+        <file>resources/32x32/media-record.png</file>
+
+        <file>resources/22x22/media-seek-backward.png</file>
+        <file>resources/32x32/media-seek-backward.png</file>
+
+        <file>resources/22x22/media-seek-forward.png</file>
+        <file>resources/32x32/media-seek-forward.png</file>
+
+        <file>resources/22x22/media-skip-backward.png</file>
+        <file>resources/32x32/media-skip-backward.png</file>
+
+        <file>resources/22x22/media-skip-forward.png</file>
+        <file>resources/32x32/media-skip-forward.png</file>
+
+        <file>resources/22x22/utilities-terminal.png</file>
+        <file>resources/32x32/utilities-terminal.png</file>
+    </qresource>
+</RCC>

ground/gcs/src/plugins/video/video.ui

@@ -0,0 +1,204 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>Form</class>
+ <widget class="QWidget" name="Form">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>400</width>
+    <height>572</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <property name="autoFillBackground">
+   <bool>false</bool>
+  </property>
+  <layout class="QVBoxLayout">
+   <property name="spacing">
+    <number>0</number>
+   </property>
+   <property name="leftMargin">
+    <number>0</number>
+   </property>
+   <property name="topMargin">
+    <number>0</number>
+   </property>
+   <property name="rightMargin">
+    <number>0</number>
+   </property>
+   <property name="bottomMargin">
+    <number>0</number>
+   </property>
+   <item>
+    <widget class="VideoWidget" name="video" native="true">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Preferred" vsizetype="Expanding">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <widget class="QTextBrowser" name="consoleTextBrowser">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Expanding" vsizetype="Minimum">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="lineWrapMode">
+      <enum>QTextEdit::NoWrap</enum>
+     </property>
+    </widget>
+   </item>
+   <item>
+    <layout class="QVBoxLayout" name="verticalLayout">
+     <property name="spacing">
+      <number>0</number>
+     </property>
+     <property name="leftMargin">
+      <number>0</number>
+     </property>
+     <property name="topMargin">
+      <number>0</number>
+     </property>
+     <property name="rightMargin">
+      <number>0</number>
+     </property>
+     <property name="bottomMargin">
+      <number>0</number>
+     </property>
+     <item>
+      <layout class="QHBoxLayout" name="horizontalLayout">
+       <property name="leftMargin">
+        <number>6</number>
+       </property>
+       <property name="topMargin">
+        <number>6</number>
+       </property>
+       <property name="rightMargin">
+        <number>6</number>
+       </property>
+       <property name="bottomMargin">
+        <number>6</number>
+       </property>
+       <item>
+        <layout class="QHBoxLayout" name="horizontalLayout_3">
+         <item>
+          <widget class="QPushButton" name="startButton">
+           <property name="text">
+            <string/>
+           </property>
+           <property name="icon">
+            <iconset>
+             <normaloff>:/video/resources/22x22/media-playback-start.png</normaloff>
+             <normalon>:/video/resources/22x22/media-playback-start.png</normalon>:/video/resources/22x22/media-playback-start.png</iconset>
+           </property>
+           <property name="iconSize">
+            <size>
+             <width>22</width>
+             <height>22</height>
+            </size>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QPushButton" name="pauseButton">
+           <property name="text">
+            <string/>
+           </property>
+           <property name="icon">
+            <iconset>
+             <normaloff>:/video/resources/22x22/media-playback-pause.png</normaloff>
+             <normalon>:/video/resources/22x22/media-playback-pause.png</normalon>:/video/resources/22x22/media-playback-pause.png</iconset>
+           </property>
+           <property name="iconSize">
+            <size>
+             <width>22</width>
+             <height>22</height>
+            </size>
+           </property>
+          </widget>
+         </item>
+         <item>
+          <widget class="QPushButton" name="stopButton">
+           <property name="mouseTracking">
+            <bool>true</bool>
+           </property>
+           <property name="text">
+            <string/>
+           </property>
+           <property name="icon">
+            <iconset>
+             <normaloff>:/video/resources/22x22/media-playback-stop.png</normaloff>
+             <normalon>:/video/resources/22x22/media-playback-stop.png</normalon>:/video/resources/22x22/media-playback-stop.png</iconset>
+           </property>
+           <property name="iconSize">
+            <size>
+             <width>22</width>
+             <height>22</height>
+            </size>
+           </property>
+          </widget>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <spacer name="horizontalSpacer">
+         <property name="orientation">
+          <enum>Qt::Horizontal</enum>
+         </property>
+         <property name="sizeHint" stdset="0">
+          <size>
+           <width>40</width>
+           <height>20</height>
+          </size>
+         </property>
+        </spacer>
+       </item>
+       <item>
+        <layout class="QHBoxLayout" name="horizontalLayout_2">
+         <item>
+          <widget class="QPushButton" name="consoleButton">
+           <property name="mouseTracking">
+            <bool>true</bool>
+           </property>
+           <property name="text">
+            <string/>
+           </property>
+           <property name="icon">
+            <iconset>
+             <normaloff>:/video/resources/22x22/utilities-terminal.png</normaloff>
+             <normalon>:/video/resources/22x22/utilities-terminal.png</normalon>:/video/resources/22x22/utilities-terminal.png</iconset>
+           </property>
+           <property name="iconSize">
+            <size>
+             <width>22</width>
+             <height>22</height>
+            </size>
+           </property>
+          </widget>
+         </item>
+        </layout>
+       </item>
+      </layout>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <customwidgets>
+  <customwidget>
+   <class>VideoWidget</class>
+   <extends>QWidget</extends>
+   <header>videowidget.h</header>
+   <container>1</container>
+  </customwidget>
+ </customwidgets>
+ <resources/>
+ <connections/>
+</ui>

ground/gcs/src/plugins/video/videogadget.cpp

@@ -0,0 +1,46 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadget.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "videogadgetconfiguration.h"
+#include "videogadgetwidget.h"
+#include "videogadget.h"
+
+VideoGadget::VideoGadget(QString classId, VideoGadgetWidget *widget, QWidget *parent) :
+    IUAVGadget(classId, parent),
+    m_widget(widget)
+{}
+
+VideoGadget::~VideoGadget()
+{
+    delete m_widget;
+}
+
+void VideoGadget::loadConfiguration(IUAVGadgetConfiguration *config)
+{
+    VideoGadgetConfiguration *m = qobject_cast<VideoGadgetConfiguration *>(config);
+
+    m_widget->setConfiguration(m);
+}

ground/gcs/src/plugins/video/videogadget.h

@@ -0,0 +1,70 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadget.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOGADGET_H_
+#define VIDEOGADGET_H_
+
+#include <coreplugin/iuavgadget.h>
+#include "videogadgetwidget.h"
+
+namespace Core {
+class IUAVGadget;
+}
+
+class IUAVGadget;
+class QWidget;
+class QString;
+class VideoGadgetWidget;
+
+using namespace Core;
+
+class VideoGadget : public Core::IUAVGadget {
+    Q_OBJECT
+public:
+    VideoGadget(QString classId, VideoGadgetWidget *widget, QWidget *parent = 0);
+    ~VideoGadget();
+
+    QList<int> context() const
+    {
+        return m_context;
+    }
+    QWidget *widget()
+    {
+        return m_widget;
+    }
+    void loadConfiguration(IUAVGadgetConfiguration *config);
+    QString contextHelpId() const
+    {
+        return QString();
+    }
+
+private:
+    VideoGadgetWidget *m_widget;
+    QList<int> m_context;
+};
+
+#endif // VIDEOGADGET_H_

ground/gcs/src/plugins/video/videogadgetconfiguration.cpp

@@ -0,0 +1,73 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetconfiguration.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "videogadgetconfiguration.h"
+
+VideoGadgetConfiguration::VideoGadgetConfiguration(QString classId, QSettings &settings, QObject *parent) :
+    IUAVGadgetConfiguration(classId, parent)
+{
+    m_displayVideo       = settings.value("displayVideo").toBool();
+    m_autoStart          = settings.value("autoStart").toBool();
+    m_displayControls    = settings.value("displayControls").toBool();
+    m_respectAspectRatio = settings.value("respectAspectRatio").toBool();
+    m_pipelineDesc       = settings.value("pipelineDesc").toString();
+    m_pipelineInfo       = settings.value("pipelineInfo").toString();
+}
+
+VideoGadgetConfiguration::VideoGadgetConfiguration(const VideoGadgetConfiguration &obj) :
+    IUAVGadgetConfiguration(obj.classId(), obj.parent())
+{
+    m_displayVideo       = obj.m_displayVideo;
+    m_autoStart          = obj.m_autoStart;
+    m_displayControls    = obj.m_displayControls;
+    m_respectAspectRatio = obj.m_respectAspectRatio;
+    m_pipelineDesc       = obj.m_pipelineDesc;
+    m_pipelineInfo       = obj.m_pipelineInfo;
+}
+
+/**
+ * Clones a configuration.
+ *
+ */
+IUAVGadgetConfiguration *VideoGadgetConfiguration::clone() const
+{
+    return new VideoGadgetConfiguration(*this);
+}
+
+/**
+ * Saves a configuration.
+ *
+ */
+void VideoGadgetConfiguration::saveConfig(QSettings &settings) const
+{
+    settings.setValue("displayVideo", m_displayVideo);
+    settings.setValue("autoStart", m_autoStart);
+    settings.setValue("displayControls", m_displayControls);
+    settings.setValue("respectAspectRatio", m_respectAspectRatio);
+    settings.setValue("pipelineDesc", m_pipelineDesc);
+    settings.setValue("pipelineInfo", m_pipelineInfo);
+}

ground/gcs/src/plugins/video/videogadgetconfiguration.h

@@ -0,0 +1,104 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetconfiguration.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOGADGETCONFIGURATION_H
+#define VIDEOGADGETCONFIGURATION_H
+
+#include <coreplugin/iuavgadgetconfiguration.h>
+
+using namespace Core;
+
+class VideoGadgetConfiguration : public IUAVGadgetConfiguration {
+    Q_OBJECT
+public:
+    explicit VideoGadgetConfiguration(QString classId, QSettings &Settings, QObject *parent = 0);
+    explicit VideoGadgetConfiguration(const VideoGadgetConfiguration &obj);
+
+    IUAVGadgetConfiguration *clone() const;
+    void saveConfig(QSettings &settings) const;
+
+    bool displayVideo() const
+    {
+        return m_displayVideo;
+    }
+    void setDisplayVideo(bool displayVideo)
+    {
+        m_displayVideo = displayVideo;
+    }
+    bool displayControls() const
+    {
+        return m_displayControls;
+    }
+    void setDisplayControls(bool displayControls)
+    {
+        m_displayControls = displayControls;
+    }
+    bool autoStart() const
+    {
+        return m_autoStart;
+    }
+    void setAutoStart(bool autoStart)
+    {
+        m_autoStart = autoStart;
+    }
+    bool respectAspectRatio() const
+    {
+        return m_respectAspectRatio;
+    }
+    void setRespectAspectRatio(bool respectAspectRatio)
+    {
+        m_respectAspectRatio = respectAspectRatio;
+    }
+    QString pipelineDesc() const
+    {
+        return m_pipelineDesc;
+    }
+    void setPipelineDesc(QString pipelineDesc)
+    {
+        m_pipelineDesc = pipelineDesc;
+    }
+    QString pipelineInfo() const
+    {
+        return m_pipelineInfo;
+    }
+    void setPipelineInfo(QString pipelineInfo)
+    {
+        m_pipelineInfo = pipelineInfo;
+    }
+
+private:
+    // video
+    bool m_displayVideo;
+    bool m_respectAspectRatio;
+    // controls
+    bool m_displayControls;
+    bool m_autoStart;
+    QString m_pipelineDesc;
+    QString m_pipelineInfo;
+};
+
+#endif // VIDEOGADGETCONFIGURATION_H

ground/gcs/src/plugins/video/videogadgetfactory.cpp

@@ -0,0 +1,57 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetfactory.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "videogadgetfactory.h"
+#include "videogadgetwidget.h"
+#include "videogadget.h"
+#include "videogadgetconfiguration.h"
+#include "videogadgetoptionspage.h"
+#include <coreplugin/uavgadgetoptionspagedecorator.h>
+#include <coreplugin/iuavgadget.h>
+
+VideoGadgetFactory::VideoGadgetFactory(QObject *parent) :
+    IUAVGadgetFactory(QString("VideoGadget"), tr("Video"), parent)
+{}
+
+VideoGadgetFactory::~VideoGadgetFactory()
+{}
+
+Core::IUAVGadget *VideoGadgetFactory::createGadget(QWidget *parent)
+{
+    VideoGadgetWidget *gadgetWidget = new VideoGadgetWidget(parent);
+
+    return new VideoGadget(QString("VideoGadget"), gadgetWidget, parent);
+}
+
+IUAVGadgetConfiguration *VideoGadgetFactory::createConfiguration(QSettings &settings)
+{
+    return new VideoGadgetConfiguration(QString("VideoGadget"), settings);
+}
+
+IOptionsPage *VideoGadgetFactory::createOptionsPage(IUAVGadgetConfiguration *config)
+{
+    return new VideoGadgetOptionsPage(qobject_cast<VideoGadgetConfiguration *>(config));
+}

ground/gcs/src/plugins/video/videogadgetfactory.h

@@ -0,0 +1,51 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetfactory.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOGADGETFACTORY_H_
+#define VIDEOGADGETFACTORY_H_
+
+#include <coreplugin/iuavgadgetfactory.h>
+
+namespace Core {
+class IUAVGadget;
+class IUAVGadgetFactory;
+}
+
+using namespace Core;
+
+class VideoGadgetFactory : public IUAVGadgetFactory {
+    Q_OBJECT
+public:
+    VideoGadgetFactory(QObject *parent = 0);
+    ~VideoGadgetFactory();
+
+    IUAVGadget *createGadget(QWidget *parent);
+    IUAVGadgetConfiguration *createConfiguration(QSettings &settings);
+    IOptionsPage *createOptionsPage(IUAVGadgetConfiguration *config);
+};
+
+#endif // VIDEOGADGETFACTORY_H_

ground/gcs/src/plugins/video/videogadgetoptionspage.cpp

@@ -0,0 +1,82 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetoptionspage.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "videogadgetoptionspage.h"
+#include "videogadgetconfiguration.h"
+#include "helpdialog.h"
+
+#include "ui_videooptionspage.h"
+
+VideoGadgetOptionsPage::VideoGadgetOptionsPage(VideoGadgetConfiguration *config, QObject *parent) :
+    IOptionsPage(parent), m_config(config)
+{
+    m_page = 0;
+}
+
+QWidget *VideoGadgetOptionsPage::createPage(QWidget *parent)
+{
+    m_page = new Ui::VideoOptionsPage();
+    QWidget *w = new QWidget(parent);
+    m_page->setupUi(w);
+
+    // TODO
+    m_page->respectAspectRatioCheckBox->setVisible(false);
+    m_page->helpButton->setVisible(false);
+
+    m_page->displayVideoCheckBox->setChecked(m_config->displayVideo());
+    m_page->displayControlsCheckBox->setChecked(m_config->displayControls());
+    m_page->autoStartCheckBox->setChecked(m_config->autoStart());
+    m_page->respectAspectRatioCheckBox->setChecked(m_config->respectAspectRatio());
+    m_page->descPlainTextEdit->setPlainText(m_config->pipelineDesc());
+    m_page->infoPlainTextEdit->setPlainText(m_config->pipelineInfo());
+
+    connect(m_page->helpButton, SIGNAL(clicked()), this, SLOT(openHelpDialog()));
+
+    return w;
+}
+
+void VideoGadgetOptionsPage::apply()
+{
+    m_config->setDisplayVideo(m_page->displayVideoCheckBox->isChecked());
+    m_config->setDisplayControls(m_page->displayControlsCheckBox->isChecked());
+    m_config->setAutoStart(m_page->autoStartCheckBox->isChecked());
+    m_config->setRespectAspectRatio(m_page->respectAspectRatioCheckBox->isChecked());
+    m_config->setPipelineDesc(m_page->descPlainTextEdit->toPlainText());
+    m_config->setPipelineInfo(m_page->infoPlainTextEdit->toPlainText());
+}
+
+void VideoGadgetOptionsPage::finish()
+{
+    delete m_page;
+}
+
+void VideoGadgetOptionsPage::openHelpDialog()
+{
+    HelpDialog dlg(0);
+
+    dlg.execDialog();
+}

ground/gcs/src/plugins/video/videogadgetoptionspage.h

@@ -0,0 +1,80 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetoptionspage.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOGADGETOPTIONSPAGE_H
+#define VIDEOGADGETOPTIONSPAGE_H
+
+#include "coreplugin/dialogs/ioptionspage.h"
+
+#include <QLabel>
+#include <QPlainTextEdit>
+
+class VideoGadgetConfiguration;
+
+namespace Ui {
+class VideoOptionsPage;
+}
+
+using namespace Core;
+
+class VideoGadgetOptionsPage : public IOptionsPage {
+    Q_OBJECT
+public:
+    explicit VideoGadgetOptionsPage(VideoGadgetConfiguration *config, QObject *parent = 0);
+    QString id() const
+    {
+        return "";
+    }
+    QString trName() const
+    {
+        return "";
+    }
+    QString category() const
+    {
+        return "";
+    }
+    QString trCategory() const
+    {
+        return "";
+    }
+
+    QWidget *createPage(QWidget *parent);
+    void apply();
+    void finish();
+
+// private signals:
+
+// public slots:
+private slots:
+    void openHelpDialog();
+
+private:
+    VideoGadgetConfiguration *m_config;
+    Ui::VideoOptionsPage *m_page;
+};
+
+#endif // VIDEOGADGETOPTIONSPAGE_H

ground/gcs/src/plugins/video/videogadgetwidget.cpp

@@ -0,0 +1,170 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetwidget.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "videogadgetconfiguration.h"
+#include "videogadgetwidget.h"
+#include "pipeline.h"
+
+#include <QtCore>
+#include <QDebug>
+#include <QStringList>
+#include <QTextEdit>
+#include <QPushButton>
+#include <QWidget>
+
+VideoGadgetWidget::VideoGadgetWidget(QWidget *parent) :
+    QFrame(parent)
+{
+    m_ui = new Ui_Form();
+    m_ui->setupUi(this);
+
+    m_ui->consoleTextBrowser->setVisible(false);
+
+    connect(videoWidget(), &VideoWidget::stateChanged, this, &VideoGadgetWidget::onStateChanged);
+    connect(videoWidget(), &VideoWidget::message, this, &VideoGadgetWidget::msg);
+
+    connect(m_ui->startButton, &QPushButton::clicked, this, &VideoGadgetWidget::start);
+    connect(m_ui->pauseButton, &QPushButton::clicked, this, &VideoGadgetWidget::pause);
+    connect(m_ui->stopButton, &QPushButton::clicked, this, &VideoGadgetWidget::stop);
+
+    connect(m_ui->consoleButton, &QPushButton::clicked, this, &VideoGadgetWidget::console);
+
+    onStateChanged(Pipeline::Null, Pipeline::Null, Pipeline::Null);
+}
+
+VideoGadgetWidget::~VideoGadgetWidget()
+{
+    m_ui = 0;
+}
+
+void VideoGadgetWidget::setConfiguration(VideoGadgetConfiguration *config)
+{
+    videoWidget()->setVisible(config->displayVideo());
+    // m_ui->control->setEnabled(config->displayControls());
+    bool restart = false;
+    if (videoWidget()->pipelineDesc() != config->pipelineDesc()) {
+        if (videoWidget()->isPlaying()) {
+            restart = true;
+            stop();
+        }
+        msg(QString("setting pipeline %0").arg(config->pipelineDesc()));
+        videoWidget()->setPipelineDesc(config->pipelineDesc());
+    }
+    if (restart || (!videoWidget()->isPlaying() && config->autoStart())) {
+        start();
+    }
+}
+
+void VideoGadgetWidget::start()
+{
+    msg(QString("starting..."));
+    m_ui->startButton->setEnabled(false);
+    videoWidget()->start();
+}
+
+void VideoGadgetWidget::pause()
+{
+    msg(QString("pausing..."));
+    m_ui->pauseButton->setEnabled(false);
+    videoWidget()->pause();
+}
+
+void VideoGadgetWidget::stop()
+{
+    msg(QString("stopping..."));
+    videoWidget()->stop();
+}
+
+void VideoGadgetWidget::console()
+{
+    m_ui->consoleTextBrowser->setVisible(!m_ui->consoleTextBrowser->isVisible());
+}
+
+void VideoGadgetWidget::onStateChanged(Pipeline::State oldState, Pipeline::State newState, Pipeline::State pendingState)
+{
+    Q_UNUSED(oldState);
+
+    // msg(QString("state changed: ") + VideoWidget::name(oldState) + " -> " + VideoWidget::name(newState) + " / " + VideoWidget::name(pendingState));
+
+    bool startEnabled = true;
+    bool pauseEnabled = true;
+    bool stopEnabled  = true;
+
+    bool startVisible = false;
+    bool pauseVisible = false;
+    bool stopVisible  = true;
+
+    switch (newState) {
+    case Pipeline::Ready:
+        // start & !stop
+        startVisible = true;
+        stopEnabled  = false;
+        break;
+    case Pipeline::Paused:
+        if (pendingState == Pipeline::Playing) {
+            // !pause & stop
+            pauseVisible = true;
+            pauseEnabled = false;
+        } else if (pendingState == Pipeline::Ready) {
+            // start & !stop
+            startVisible = true;
+            stopEnabled  = false;
+        } else {
+            // start & stop
+            startVisible = true;
+        }
+        break;
+    case Pipeline::Playing:
+        // pause & stop
+        pauseVisible = true;
+        break;
+    default:
+        // start & !stop
+        startVisible = true;
+        stopEnabled  = false;
+        break;
+    }
+    m_ui->startButton->setVisible(startVisible);
+    m_ui->startButton->setEnabled(startEnabled);
+
+    m_ui->pauseButton->setVisible(pauseVisible);
+    m_ui->pauseButton->setEnabled(pauseEnabled);
+
+    m_ui->stopButton->setVisible(stopVisible);
+    m_ui->stopButton->setEnabled(stopEnabled);
+}
+
+void VideoGadgetWidget::msg(const QString &str)
+{
+    if (m_ui) {
+        m_ui->consoleTextBrowser->append(str);
+    }
+}
+
+VideoWidget *VideoGadgetWidget::videoWidget()
+{
+    return m_ui->video;
+}

ground/gcs/src/plugins/video/videogadgetwidget.h

@@ -0,0 +1,68 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videogadgetwidget.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOGADGETWIDGET_H_
+#define VIDEOGADGETWIDGET_H_
+
+#include "pipeline.h"
+#include "ui_video.h"
+
+#include <QFrame>
+#include <QtCore/QEvent>
+#include <QtGui/QResizeEvent>
+#include <QtGui/QPaintEvent>
+
+class VideoWidget;
+class VideoGadgetConfiguration;
+
+class VideoGadgetWidget : public QFrame {
+    Q_OBJECT
+
+public:
+    VideoGadgetWidget(QWidget *parent = 0);
+    ~VideoGadgetWidget();
+
+    void setConfiguration(VideoGadgetConfiguration *config);
+
+private slots:
+    void start();
+    void pause();
+    void stop();
+    void console();
+
+    void onStateChanged(Pipeline::State oldState, Pipeline::State newState, Pipeline::State pendingState);
+
+private:
+    Ui_Form *m_ui;
+    VideoGadgetConfiguration *config;
+
+    void msg(const QString &str);
+
+    VideoWidget *videoWidget();
+};
+
+#endif /* VIDEOGADGETWIDGET_H_ */

ground/gcs/src/plugins/video/videooptionspage.ui

@@ -0,0 +1,96 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>VideoOptionsPage</class>
+ <widget class="QWidget" name="VideoOptionsPage">
+  <property name="geometry">
+   <rect>
+    <x>0</x>
+    <y>0</y>
+    <width>378</width>
+    <height>300</height>
+   </rect>
+  </property>
+  <property name="windowTitle">
+   <string>Form</string>
+  </property>
+  <layout class="QGridLayout" name="gridLayout">
+   <property name="margin">
+    <number>0</number>
+   </property>
+   <item row="6" column="0">
+    <widget class="QLabel" name="descLabel">
+     <property name="text">
+      <string>Pipeline:</string>
+     </property>
+    </widget>
+   </item>
+   <item row="6" column="1">
+    <widget class="QPlainTextEdit" name="descPlainTextEdit"/>
+   </item>
+   <item row="1" column="1">
+    <widget class="QCheckBox" name="displayVideoCheckBox">
+     <property name="text">
+      <string>Display video</string>
+     </property>
+    </widget>
+   </item>
+   <item row="2" column="1">
+    <widget class="QCheckBox" name="displayControlsCheckBox">
+     <property name="text">
+      <string>Display controls</string>
+     </property>
+    </widget>
+   </item>
+   <item row="7" column="1">
+    <widget class="QPlainTextEdit" name="infoPlainTextEdit"/>
+   </item>
+   <item row="7" column="0">
+    <widget class="QLabel" name="infoLabel">
+     <property name="text">
+      <string>Info:</string>
+     </property>
+    </widget>
+   </item>
+   <item row="3" column="1">
+    <widget class="QCheckBox" name="autoStartCheckBox">
+     <property name="text">
+      <string>Auto Start</string>
+     </property>
+    </widget>
+   </item>
+   <item row="4" column="1">
+    <widget class="QCheckBox" name="respectAspectRatioCheckBox">
+     <property name="text">
+      <string>Respect aspect ratio</string>
+     </property>
+    </widget>
+   </item>
+   <item row="8" column="1">
+    <layout class="QHBoxLayout" name="horizontalLayout">
+     <item>
+      <spacer name="horizontalSpacer">
+       <property name="orientation">
+        <enum>Qt::Horizontal</enum>
+       </property>
+       <property name="sizeHint" stdset="0">
+        <size>
+         <width>40</width>
+         <height>20</height>
+        </size>
+       </property>
+      </spacer>
+     </item>
+     <item>
+      <widget class="QPushButton" name="helpButton">
+       <property name="text">
+        <string>Help</string>
+       </property>
+      </widget>
+     </item>
+    </layout>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>

ground/gcs/src/plugins/video/videoplugin.cpp

@@ -0,0 +1,64 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videoplugin.cpp
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+#include "videoplugin.h"
+#include "videogadgetfactory.h"
+
+#include <extensionsystem/pluginmanager.h>
+
+#include <QDebug>
+#include <QtPlugin>
+#include <QStringList>
+
+VideoPlugin::VideoPlugin()
+{
+    // Do nothing
+}
+
+VideoPlugin::~VideoPlugin()
+{
+    // Do nothing
+}
+
+bool VideoPlugin::initialize(const QStringList & args, QString *errMsg)
+{
+    Q_UNUSED(args);
+    Q_UNUSED(errMsg);
+    mf = new VideoGadgetFactory(this);
+    addAutoReleasedObject(mf);
+
+    return true;
+}
+
+void VideoPlugin::extensionsInitialized()
+{
+    // Do nothing
+}
+
+void VideoPlugin::shutdown()
+{
+    // Do nothing
+}

ground/gcs/src/plugins/video/videoplugin.h

@@ -0,0 +1,51 @@
+/**
+ ******************************************************************************
+ *
+ * @file       videoplugin.h
+ * @author     The LibrePilot Project, http://www.librepilot.org Copyright (C) 2017.
+ * @addtogroup GCSPlugins GCS Plugins
+ * @{
+ * @addtogroup VideoGadgetPlugin Video Gadget Plugin
+ * @{
+ * @brief A video gadget plugin
+ *****************************************************************************/
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef VIDEOPLUGIN_H_
+#define VIDEOPLUGIN_H_
+
+#include <extensionsystem/iplugin.h>
+
+class VideoGadgetFactory;
+
+class VideoPlugin : public ExtensionSystem::IPlugin {
+    Q_OBJECT
+                                            Q_PLUGIN_METADATA(IID "OpenPilot.Video")
+public:
+
+    VideoPlugin();
+    ~VideoPlugin();
+
+    void extensionsInitialized();
+    bool initialize(const QStringList &arguments, QString *errorString);
+    void shutdown();
+
+private:
+    VideoGadgetFactory *mf;
+};
+
+#endif /* VIDEOPLUGIN_H_ */

ground/gcs/src/share/configurations/default.xml

@@ -2785,6 +2785,128 @@
         </data>
       </default>
     </UAVObjectBrowser>
+    <VideoGadget>
+      <Default>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>true</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>videotestsrc ! autovideosink</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>false</respectAspectRatio>
+        </data>
+      </Default>
+      <Screen__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file__PCT__20__PCT__28fast__PCT__20__PCT__26__PCT__20big__PCT__29>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>false</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>dx9screencapsrc monitor=0 cursor=true ! tee name=t
+  t. ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 ! timeoverlay ! autovideosink
+  t. ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 ! videoconvert ! x264enc interlaced=true pass=quant quantizer=0 speed-preset=ultrafast byte-stream=true ! mpegpsmux ! filesink location=capture_fast.mpg</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>true</respectAspectRatio>
+        </data>
+      </Screen__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file__PCT__20__PCT__28fast__PCT__20__PCT__26__PCT__20big__PCT__29>
+      <Screen__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>false</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>dx9screencapsrc monitor=0 cursor=true ! tee name=t
+    t. ! queue ! timeoverlay ! autovideosink
+    t. ! queue ! videoconvert ! x264enc tune=zerolatency tune=zerolatency bitrate=498 ! mpegpsmux ! filesink location=capture.mpg</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>true</respectAspectRatio>
+        </data>
+      </Screen__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file>
+      <Screen__PCT__20-__PCT__20Play__PCT__20__PCT__28640x480__PCT__29>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>false</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>dx9screencapsrc monitor=0 cursor=true x=0 y=0 width=640 height=480 ! autovideosink</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>false</respectAspectRatio>
+        </data>
+      </Screen__PCT__20-__PCT__20Play__PCT__20__PCT__28640x480__PCT__29>
+      <Screen__PCT__20-__PCT__20Play>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>true</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>dx9screencapsrc monitor=0 cursor=true ! autovideosink</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>false</respectAspectRatio>
+        </data>
+      </Screen__PCT__20-__PCT__20Play>
+      <USB__PCT__20Camera__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file__PCT__20__PCT__28fast__PCT__20__PCT__26__PCT__20big__PCT__29>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>false</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>ksvideosrc device-index=0 ! tee name=t
+  t. ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 ! timeoverlay ! autovideosink
+  t. ! queue max-size-buffers=0 max-size-time=0 max-size-bytes=0 ! videoconvert ! x264enc interlaced=true pass=quant quantizer=0 speed-preset=ultrafast byte-stream=true ! mpegpsmux ! filesink location=capture_fast.mpg</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>true</respectAspectRatio>
+        </data>
+      </USB__PCT__20Camera__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file__PCT__20__PCT__28fast__PCT__20__PCT__26__PCT__20big__PCT__29>
+      <USB__PCT__20Camera__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>false</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>ksvideosrc device-index=0 ! tee name=t
+    t. ! queue ! timeoverlay ! autovideosink
+    t. ! queue ! videoconvert ! x264enc tune=zerolatency tune=zerolatency bitrate=498 ! mpegpsmux ! filesink location=capture.mpg</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>true</respectAspectRatio>
+        </data>
+      </USB__PCT__20Camera__PCT__20-__PCT__20Capture__PCT__20to__PCT__20file>
+      <USB__PCT__20Camera__PCT__20-__PCT__20Play>
+        <configInfo>
+          <locked>false</locked>
+          <version>0.0.0</version>
+        </configInfo>
+        <data>
+          <autoStart>true</autoStart>
+          <displayControls>false</displayControls>
+          <displayVideo>true</displayVideo>
+          <pipelineDesc>ksvideosrc device-index=0 ! autovideosink</pipelineDesc>
+          <pipelineInfo></pipelineInfo>
+          <respectAspectRatio>false</respectAspectRatio>
+        </data>
+      </USB__PCT__20Camera__PCT__20-__PCT__20Play>
+    </VideoGadget>
     <configInfo>
       <locked>false</locked>
       <version>1.2.0</version>