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Code Issues Releases Activity

Make it able to read stdin if no file provided.

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This commit is contained in:
Richard Hirst 2012-12-17 22:13:03 +00:00
parent 2a8e0b8f5f
commit a4ee68bb3f
1 changed files with 41 additions and 10 deletions
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51
PiFmDma/PiFmDma.c
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@ -36,6 +36,23 @@
* ACCEPT NO LIABILITY OR RESPONSIBILITY FOR ANYTHING THAT HAPPENS AS A RESULT
* OF YOU RUNNING THIS CODE. IF IT BREAKS, YOU GET TO KEEP ALL THE PIECES.
*
* NOTE ALSO: THIS MAY BE ILLEGAL IN YOUR COUNTRY. HERE ARE SOME COMMENTS
* FROM MORE KNOWLEDGEABLE PEOPLE ON THE FORUM:
*
* "Just be aware that in some countries FM broadcast and especially long
* distance FM broadcast could get yourself into trouble with the law, stray FM
* broadcasts over Airband aviation is also strictly forbidden."
*
* "A low pass filter is really really required for this as it has strong
* harmonics at the 3rd, 5th 7th and 9th which sit in licensed and rather
* essential bands, ie GSM, HAM, emergency services and others. Polluting these
* frequencies is immoral and dangerous, whereas "breaking in" on FM bands is
* just plain illegal."
*
* "Don't get caught, this GPIO use has the potential to exceed the legal
* limits by about 2000% with a proper aerial."
*
*
* As for the original code, this code is released under the GPL.
*
* Richard Hirst <richardghirst@gmail.com> December 2012
@ -338,15 +355,22 @@ main(int argc, char **argv)
dma_reg[DMA_CS] = 0x10880001; // go, mid priority, wait for outstanding writes
// Nearly there.. open the .wav file specified on the cmdline
int fp = open(argv[1], 'r');
fd = 0;
if (fp < 0)
fatal("Failed to open .wav file\n");
int sz = lseek(fp, 0L, SEEK_END);
lseek(fp, 0L, SEEK_SET);
if (argc > 1) {
fd = open(argv[1], 'r');
short* data = (short*)malloc(sz);
read(fp, data, sz);
if (fd < 0)
fatal("Failed to open .wav file\n");
}
short data[1024];
int data_len = read(fd, data, sizeof(data));
if (data_len < 0)
fatal("Failed to read .wav file\n");
data_len /= 2;
if (data_len < 23)
fatal("Initial read of .wav file too short\n");
uint32_t last_cb = (uint32_t)ctl->cb;
int data_index = 22;
@ -377,9 +401,16 @@ main(int argc, char **argv)
last_sample = 0;
}
free_slots -= 10;
// Should really wait for outstanding samples to be processed here..
if (++data_index >= sz/2)
terminate(0);
if (++data_index >= data_len) {
data_len = read(fd, data, sizeof(data));
data_index = 0;
if (data_len < 0)
fatal("Error reading data: %m\n");
// Should really wait for outstanding samples to be processed here..
data_len /= 2;
if (data_len == 0)
terminate(0);
}
}
last_cb = (uint32_t)virtbase + last_sample * sizeof(dma_cb_t) * 2;
}