On Wed, 28.10.09 18:14, pl bossart (bossart.nospam at gmail.com) wrote: > Hi all, > I have lost the afternoon chasing an audio quality issue with PA > configured with tsched=0 and small fragments (<30ms). I am doing this > on purpose to profile the behavior of PulseAudio with lots of wakeups > and samples provided in chunks at once. > With the latest 0.9.19 version I have cracking noise but no reports of > underflows, it works fine maybe once in 20 trials. With 0.9.15, no > issue at all, I can even go down to fragments of 2ms without any > issue. This is on a Atom board with classic HDAudio. I have no problem > at all in both cases with aplay -Dhw. What I noticed though is that > aplay seems to select a period size and buffer size that are multiples > of 128 bytes. For example a period of 5ms at 48kHz is actually > configured as 5.33ms and 256 frames; I suspect an alignement issue > that would cause these noises. > > I have an intuition that the regression was introduced by the ALSA > configuration rewrite > SHA:557c4295107dc7374c850b0bd5331dd35e8fdd0f , > but before I go on with a dichotomy and try to fix the issue I wanted > to check if others faced the same problem. I wonder if the issues raised by Alexandre Savard on the ML here recently might actually be the same issue. If you compare the output of snd_pcm_dump() for 0.9.15 and 0.9.19 on your card, is there any obvious difference? (snd_pcm_dump() is called as part of the normal setup these days and dumped to stderr when debug logging is on. the snd_pcm_dump() output looks like this: http://fpaste.org/X9Vh/) Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net http://0pointer.net/lennart/ GnuPG 0x1A015CC4
