[pulseaudio-discuss] How to control latency with CLI?

[Tanu Kaskinen]

On Tue, 2017-09-19 at 19:07 +0930, Steven Wawryk wrote:
> Hello,
> 
> I'm trying to work out how to control latency with pulseaudio CLI scripts.
> 
> We're finding that latency varies between a few seconds to about 80 seconds.
> 
> We have a system which uses a dedicated embedded board for many channels 
> of audio I/O.  Workstations
> connect with the I/O board using RTP over a network.
> 
> Pulseaudio 8.0 is used on both I/O board and workstation platforms, both 
> using pulseaudio CLI scripts.
> Modules explicitly loaded include instances of module-rtp-send, 
> module-rtp-recv, module-null-sink,
> module-remap-source, module-remap-sink and module-loopback.
> 
> This all works as far as it goes, but with VoIP (using 1 channel in each 
> direction), we're finding
> that the latencies make it pretty much unusable.  Ideally, I need to be 
> able to put a reasonable
> upper limit on total latency.
> 
> The link 
> https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/LatencyControl/
> provides instructions for use with the API, but I can't find much about 
> controlling latency with CLI.
> A few modules appear to have latency-related parameters I can tweak, but 
> this seems to be pointless
> because other modules are adding latency that I haven't worked out how 
> to control.
> 
> Is there any way to do this?

If you're seeing 80 second latencies, I think the only place in which
that amount could accumulate is module-loopback. PulseAudio 11.0 has a
big improvement in the module-loopback latency regulation, so I
recommend upgrading.

-- 
Tanu

https://www.patreon.com/tanuk