[pulseaudio-discuss] Pulse audio echo module problem with Alsa

[Alexander E. Patrakov]

16.05.2014 11:47, Dheeraj Kumar Dodda wrote:
> Hi All,
>
> I'm trying to use the echo cancellation module on my embedded platform,To make voip call ,
>
> These are the steps i followed,
> pulseaudio -v
> pactl load-module module-echo-cancel
> export pulse_prop=filter.apply=echo-cancel
>
> I started voip, These are the errors I am getting
>
> module-echo-cancel.c: Playback after capture (-1589177), drop sink 101726
> module-echo-cancel.c: Playback after capture (-1699880), drop sink 108812
> module-echo-cancel.c: Playback after capture (-1721343), drop sink 110184
> asyncq.c: q overrun, queuing locally
> asyncq.c: q overrun, queuing locally
> asyncq.c: q overrun, queuing locally

> W: [alsa-source-SGTL5000 SGTL5000-0] asyncq.c: q overrun, queuing locally
> W: [alsa-source-SGTL5000 SGTL5000-0] asyncq.c: q overrun, queuing locally
> W: [alsa-source-SGTL5000 SGTL5000-0] asyncq.c: q overrun, queuing locally
> E: [alsa-source-SGTL5000 SGTL5000-0] module-echo-cancel.c: Playback after capture (-2082849), drop sink 133322
> W: [alsa-source-SGTL5000 SGTL5000-0] asyncq.c: q overrun, queuing locally
> E: [alsa-source-SGTL5000 SGTL5000-0] module-echo-cancel.c: Playback after capture (-1621593), drop sink 103800
> E: [alsa-source-SGTL5000 SGTL5000-0] module-echo-cancel.c: Playback after capture (-1538404), drop sink 98476
> E: [alsa-source-SGTL5000 SGTL5000-0] module-echo-cancel.c: Playback after capture (-1618386), drop sink 103596

Hello.

This might happen if the CPU is not fast enough to do echo cancellation 
at the full sample rate that the hardware supports. To test the theory:

1. pacmd load-module module-echo-cancel rate=8000 channels=1
2. don't export pulse_prop
3. Run your application as you would normally do, use pavucontrol or 
"pacmd move-sink-input + pacmd move-source-output" to make sure it uses 
the echo-cancelled sink & source.

If the problem does not go away, let's hope someone else has a better 
idea what's going on.

-- 
Alexander E. Patrakov