[pulseaudio-discuss] Test and Evaluate Echo Cancellation in an Embedded Device

Arun Raghavan arun at arunraghavan.net
Mon Jul 25 03:54:16 UTC 2016

On Mon, 13 Jun 2016, at 08:08 PM, Caio wrote:
> Hello Arun,
> Finally I got some good results.
> I'm loading the AEC echo cancell module using this cmd line.
> pactl load-module module-echo-cancel source_name=echosource
> sink_name=echosink aec_method=webrtc channels=1 rate=8000
> sink_properties=device.description="Noise_Reduction"
> aec_args="analog_gain_control=0\ digital_gain_control=0\
> drift_compensation=1 save_aec=1"
> OBS: I tried to use save_aec but I did not  succeed, the files are
> created
> in the /tmp but all the files were with lenght=0 bytes.
> @Arun
> These underflows sound bad. Does capture work fine without AEC?
> The capture works good without AEC, I fix the capture with AEC using
> tsched=0.
> I configured the rate and audio format in gstreamer and pulse to
> format=S16LE and rate=8000. I used the tsched=0 to "fix" the audio
> crackling, I don't know if is the best option to do, but works. I would
> like to know if is a good choice.

That sounds like your CPU isn't able to keep up at higher rates. Worth
checking whether that's the case, and whether that is expected on your
hardware. If not, maybe make sure you've compiled with the appropriate
optimisations (for speex and webrtc-audio-processing).

-- Arun

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