[pulseaudio-discuss] Playback pauses

[David Henningsson]

On 02/11/2013 11:03 AM, Dmitri Paduchikh wrote:
> Hello,
>
> When I play a sound using paplay (or aplay with ALSA configured to use
> PulseAudio) there is a big pause between two successive runs. For
> example:
>
> $ paplay sound1.wav; paplay sound2.wav
>
> The pause between these sounds is something about two seconds. I've
> tried to adjust latency (through --latency-msec=50) but this doesn't
> seem to change much.
>
> Couldn't you explain what is the cause of this pause? Is it possible to
> eliminate it?
>

This is a well-known issue which we discussed briefly at PulseConf. 
Fixing it is not trivial, unfortunately.

I did a quick test here; and for me the delay is 250 - 500 ms, which is 
consistent with the output of pacmd list-sinks:

	configured latency: 0.00 ms; range is 0.50 .. 371.52 ms

Is your maximum latency going up to about 2000 ms? What distro are you 
running?

There was some effort a while ago to try to increase this to 2000 ms in 
order to reduce power consumption, and I think we had that in Ubuntu too 
at some point? I don't know why this is now down to 371 ms, but given 
that gstreamer has a latency or similar magnitude (200 - 400 ms, IIRC) 
for media playback anyway, I see little reason to investigate it 
further. And in addition, it helps a bit against this bug. :-)


-- 
David Henningsson, Canonical Ltd.
https://launchpad.net/~diwic