[pulseaudio-discuss] synchronous over IP network

[Colin Guthrie]

'Twas brillig, and Michael Dressel at 21/06/10 16:43 did gyre and gimble:
> Is it possible that the choppy sound I still get is due to mismatch between
> the rate and number of channels on the net to the rate and channels used
> by pulseaudio or alsa?

Unlikely I reckon. If you can play OK directly on the remote machine
(PULSE_SERVER=foo paplay /path/to/some/sound.wav) then that part of it
should be fine. Likewise if you can play locally then all should
ultimately be well.

Tunnels can be a bit tricky at times and I'm not really certain that
they've had all that much love recently. They probably need some kind of
dynamic buffer support to prevent dropouts on some networks types (e.g.
WiFi) and it will also be affected by the client application (e.g.
clients that request large latencies - gstreamer media player
applications for example) will likely fare well, but applications not
designed for this (i.e. most of them) or those that specifically want
short latencies will not function as well (as they don't pump much data
into the buffers).

> Anyway is it fair to say that pulseaudio is not designed to provide
> synchronous audio distributed over networks?

Well I'd say pulse has all the necessary pre-requisite designs to enable
a "good enough" version of synchronous audio distributed over local
networks, but problems from client applications' requesting short
latencies and the lack of a more dynamic buffer in the tunnel module
could contribute to making it less than ideal in some scenarios. Having
not really given it much thought, it could be the former rather than the
latter that is most to blame here (although the discontinuity sometimes
seen between a direct remote connection and a tunnelled connection does
point to some degree at the latter being involved too).

These problems can be fixed.


Col



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Colin Guthrie
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http://colin.guthr.ie/

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