module-combine-sink causes playback problems
I am experiencing several sound issues on my system:
-
When I open pavucontrol playback of whatever is being played at the moment completely stops for several seconds, and when it finally resumes there are several more short pauses that sound a bit like buffer underruns.
-
When I open a video in VLC I experience similar "underruns", i.e. several short pauses when the playback starts. Similarly after resuming paused playback, though not always.
-
Ocasionally the sound is played too fast when resuming paused playback in xine-based applications. In addition, when the pause has been long there is often a short "underrun" several seconds after resuming playback.
These problems only happen when module-combine-sink is loaded.
I am on Debian Buster with kernel 5.6 and Starship/Matisse HD Audio Controller handled by snd_hda_intel
kernel module. By default Debian Buster ships with PulseAduio 12.2 and on that version there were numerous other sound glitches not described above (also specific to module-combine-sink). I upgraded PulseAudio to 13.0 (provided by Debian Backports) and there is a lot of improvement but the above problems remain.
UPDATE 14/08/2020: I have to take back what I said above about upgrade from 12.2 to 13.0 being helpful - it seems I just got lucky after restarting PA server, but the problems are just as intense. Regarding problem (3) above, the problem happens always when starting playback using a xine-based player. Around 0.5 second of the recording is being played too fast. Here's an example of how it sounds (there are two seconds of leading and trailing silence): bug And here's what it should sound like: correct Depending on the player the problem might also happen when unpausing a paused track, but it does not happen for all players. Also, if I restart PA server then the first time I start playback this problem never happens.
Additionaly, some of the games running under Wine have their sound completely messed up for the first 20-30 seconds.
Again, the above problems only happen with module-combine-sink.