[pulseaudio-discuss] a question about audio synchronization between local sink and tunnel sink

[Tanu Kaskinen]

On Wed, 2012-10-10 at 20:45 +0000, Sun, Xiaodong wrote:
> Hi,
> 
> I have a pulseaudio daemon running on one PC (with my music songs
> stored and played on this PC, let's call it PC-1). And then I setup
> another PC (let's call it PC-2) running pulseaudio daemon on it and
> enabled native TCP protocol. Then I configured (by using pacmd) PC-1
> pulseaudio to load a tunnel sink pointing to PC-2, and then loaded a
> combine sink which combines PC-2 tunnel sink and PC-1 local analog
> audio sink. Now I can hear audio from both PC-1 and PC-2 at the same
> time. But the audio playing are not synchronized between PC-1 and
> PC-2. There is a delay on PC-2 comparing with PC-1.
> 
> Now my question is, is pulseaudio designed for synchronized playback
> between local sink and tunnel sink? If yes, what kinds of parameters
> should I tune?

I had a look, and it seems like module-tunnel is tries to report pretty
accurate latency, and module-combine-sink in turn is supposed to
synchronize the outputs if they provide valid latency information. So it
looks like this should work, without any parameter tuning.
Unfortunately, if it doesn't work, I don't have much ideas for making it
work. How big is the delay between the two outputs? If you let it play
for a while, does it get better?

-- 
Tanu