Hello Tanu, that's a nice catch! Indeed this is exactly what I have, just that volume changing triggers it way more noticably, because of the high frequency of triggers. And indeed it's also there when recording from an alsa-sink.monitor. I just thought this would be fine, because the audio out of the speakers is fine, but the recorded result is broken just as with a null-sink. I could reproduce that on 3 different machines, so it's reproducable anytime. Record any audio from any sink.monitor and change volume of the stream input or the sink itself and watch it happen. I am able to grab source code out of a VCS, I can patch and I can compile, I can package and I can test and analyze. The only thing I cannot do, is writing code :( Anyway: Thank you very much. Best, Daniel 2013/11/22 Tanu Kaskinen <tanu.kaskinen at linux.intel.com> > On Fri, 2013-11-22 at 13:56 +0100, Daniel wrote: > > Dear list, > > > > I ask you for some assistance with null-sink and skipping/stutter. > > > > On client connect/disconnect and volume changes and many more things, > > pulseaudio does a buffer rewind to let the changes take effect > immediately. > > So far,s o good, on all my soundcards this works like a charm. > > > > Now I have some audio stream setup where I play audio to a null-sink and > > record it from null.monitor. This works really great, until some action > > like pause/play, volume change, or connecting another audio client is > > causing a rewind. Then the recorded audio hangs for approx 200ms or even > > more. On soft volume changes, there are many many rewinds done, and so I > > have many of these skips. > > > > The skipping audio is actually hanging, it does not drop any data. There > is > > just a silent break of about 200ms inserted into the stream. > > > > Of course it would be great to make rewinding on null sink just work as > it > > does on alsa sinks, but in case this is inevitable, I would be fine with > > some possibility to disable rewinding. I know that all action then are > > delayed, but that would be okay for me as the stream is delayed about 8 > > seconds anyway, until it reaches the receiver. > > There's no reason why those glitches should be inevitable, so probably > module-null-sink or the rewind handling of monitor sources in general > has some bug. Now we just need someone to send a fix for the bug... > > Not that this will help you much, but this bug might have the same root > cause: https://bugs.freedesktop.org/show_bug.cgi?id=68107 > > -- > Tanu > > -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.freedesktop.org/archives/pulseaudio-discuss/attachments/20131122/ef39de0d/attachment.html>
