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Whilst reading from my cs46xx sound card in a
while(1) loop, I have noticed that my program hangs up without giving any error
message (after making several successful reads) if I use a buffer size of 256 or
greater. If I keep the buffer size down to 128 my program doesn't
hang.
256 doesn't seem excessively large for a buffer
so I was surprised by this revalation. Is there a way around this or
it a limitation of ALSA ? Should there be a predefined upper and lower
limit for buffer sizes?
Here is a snippet of the code which hang ups after
making some successful transitions round the loop (the number varies from about
10 to 50 for each time I run the program). I am using a 16000 sampling rate and
buf contains 16 bit shorts. Any help appreciated as I am fairly new to ALSA and
sound servers in general. Regards, Pete
while(1)
{ if ((err = snd_pcm_readi (capture_handle, buf, 256)) != 256) { cout << "read from audio interface failed " << snd_strerror(err) << endl; exit (1); } cout << "out of
loop\n"; // this line never happens - so the hangup is still within
the loop
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