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):
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.