[pulseaudio-discuss] [PATCH] module-combine: limit the size of the rate adjustments

[pl bossart]

Hi Maarten,

> In the attached piece of log output this can be clearly seen. The rate
> of the stream for the null-sink varies between 47300 and 48700. I
> think this is because every time module-combine wakes up to look at
> the latencies of the slave sink inputs, it finds the null-sink with a
> different latency. I'm not sure how to fix this, may be some sort of
> avering (or even a smoother on the latency for each slave sink input)
>
> Another way of fixing it (at least getting rid of the symptoms) is by
> limiting the adjustments module-combine is doing every 10 (by default)
> seconds. The attached patch does this. The patch is roughly the fix
> proposed in http://pulseaudio.org/ticket/288

Yes the same issue happens with the loopback when capturing data from
BT or some RTP source. The latency on a standard ALSA device varies
less wildly but the adjustments are still arguable in terms of audio
quality.
I posted a rate adjustment as well a while ago which was never merged,
but that's not enough. We'd need some averaging to prevent jittery
adjustments. It's been on my TODO list for some time but if you want
to go ahead feel free :-)
-Pierre