[pulseaudio-discuss] Latency bug when module-tunnel-source and module-loopback are loaded dynamically

[Georg Chini]

On 16.10.2015 15:10, Olivier Delbeke wrote:
> Hi all,
>
> I'm bumping into a very strange issue : setting-up a tunnel between 
> two devices is OK (thanks to Georg), but only when the configuration 
> is static (=stored in the /etc/pulse/* configuration files), not when 
> the same modules are loaded after pulseaudio's start-up. In the second 
> case, all modules are loaded correctly, BUT the calculated latency of 
> the tunnel is obviously wrong, for example "current latency: 
> 26695333.53 ms". And no audio can be heard.
>
> The log is full of these :
> module-loopback.c: Loopback overall latency is 107.15 ms + 220.18 ms + 
> 13395537.50 ms = 13395864.83 ms
> module-loopback.c: Loopback overall latency is 107.34 ms + 0.00 ms + 
> 26188232.17 ms = 26188339.51 ms
> module-loopback.c: Loopback overall latency is 106.28 ms + 206.58 ms + 
> 13395547.45 ms = 13395860.31 ms
>
> On my source unit, I have a module-null-sink "default" and a 
> module-native-protocol-tcp.
>
> On the destination unit, I have the following configuration
>   load-module module-udev-detect
>   load-module module-suspend-on-idle
>   load-module module-cli-protocol-tcp
>   load-module module-tunnel-source source_name=my-tunnel  
> server=192.168.100.1 source=default.monitor
>   load-module module-loopback source=my-tunnel sink=my-alsa-sink
>
> When I start pulseaudio with this configuration, it works. But if I 
> comment the last two lines and execute them manually using "pacmd", I 
> get no audio, the messages in the log and the huge latency.
>
> Does anybody know why this happens ? And how to get rid of this (I 
> need the dynamic behavior) ?
>
> By the way, I'm using pulseaudio 6.0 . Any chance that this would be 
> fixed in pulseaudio 7.0 ?
>
> Thank you and best regards,
>
> Olivier
>
Is there some reason why you do not use the default default.pa? I would 
at least test it with
a standard setup and clean the modules later. Just to be on the safe 
side. When I tested it,
I loaded the modules manually and it worked fine.
There are a few latency issues in module-loopback and I sent a patch set 
a while ago which
is addressing them, but I doubt that those patches would help in your 
situation. You can try
them however.  See 
http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/22956
If you have problems downloading I can also send them via mail.

Regards
              Georg