[Opalvoip-devel] ALSA glithches

[Alexander S. <ale...@gm...>]

   I've discovered current trunk produce a lot of sounds artifacts on my 
system.
I see buffer underruns on write and buffer overruns on read from sound 
system.
And sound become quite "clicky".
I've tweak buffer size inside sound_alsa.cxx up to m_bufferSize(12800) 
and underruns/overruns go away.
But new with changes conopal starts acts differently. conopal start read 
and write sound in big batches.
Like this:
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.040    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.041    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.041    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.041    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.120    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.120    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.120    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.120    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.120    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.121    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.121    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.121    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.210    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.210    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.210    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.210    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.211    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.211    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.211    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.211    Media Patc...cff9df9700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.287    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.288    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640
   0:37.288    Media Patc...cff930d700      sound_alsa.cxx(412) 
ALSA          Buffer read 640 640

Same time codectest start working flawlessly (there was a lot of 
clicking also) and still read/write by one per operation.

   0:01.418       Audio:0x7f4a24e31700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:01.418       Audio:0x7f4a24e31700      sound_alsa.cxx(412) 
ALSA          Buffer read 320 320
   0:01.419       Audio:0x7f4a24e31700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:01.419       Audio:0x7f4a24e31700      sound_alsa.cxx(412) 
ALSA          Buffer read 320 320
   0:01.582       Audio:0x7f4a24e31700      sound_alsa.cxx(355) 
ALSA          Buffer write 320 320
   0:01.583       Audio:0x7f4a24e31700      sound_alsa.cxx(412) 
ALSA          Buffer read 320 320

So the logic behind those batch operations must be somethere on a higher 
levels than ALSA plugin.
My question is next: Is it ok for conopal to read in batches? Is there a 
possibility of time lag for audio?
Any thoughts?

I will try to play with buffers size next week. See if there is some 
balance for buffer size between it's size and possible lag.