Webrtcdsp stereo echo cancellation

Application Development
1

Hi,

I’ve encountered an unusual issue with echo cancellation. When the webrtcdsp is enabled, the stereo functionality seems to be impaired. I’ve isolated the problem to the following examples:

gst-launch-1.0 alsasrc ! webrtcdsp echo-cancel=false ! webrtcechoprobe ! audioconvert ! alsasink

The microphone output is directed to the left speaker, and similarly for the right speaker.
However, with this command:

gst-launch-1.0 alsasrc ! webrtcdsp echo-cancel=true ! webrtcechoprobe ! audioconvert ! alsasink

The microphone output is limited to only one channel, being played through both the left and right speakers.

Is there a specific option or capability setting I need to adjust to resolve this?

Thanks!

2

I observed that the above command works under Debian 12 with the provided gstreamer package (1.22.0) and libwebrtc-audio-processing (v0.3.1)

$ gst-inspect-1.0 webrtcdsp
[...]
Plugin Details:
  Name                     webrtcdsp
  Description              Voice pre-processing using WebRTC Audio Processing Library
  Filename                 /lib/x86_64-linux-gnu/gstreamer-1.0/libgstwebrtcdsp.so
  Version                  1.22.0
  License                  LGPL
  Source module            gst-plugins-bad
  Documentation            https://gstreamer.freedesktop.org/documentation/webrtcdsp/
  Source release date      2023-01-23
  Binary package           GStreamer Bad Plugins (Debian)
  Origin URL               https://tracker.debian.org/pkg/gst-plugins-bad1.0

But it does not with the gstreamer compiled from the sources (1.23.0.1), with libwebrtc-audio-processing (v1.3)

Plugin Details:
  Name                     webrtcdsp
  Description              Voice pre-processing using WebRTC Audio Processing Library
  Filename                 /usr/local/lib/x86_64-linux-gnu/gstreamer-1.0/libgstwebrtcdsp.so
  Version                  1.23.0.1
  License                  LGPL
  Source module            gst-plugins-bad
  Documentation            https://gstreamer.freedesktop.org/documentation/webrtcdsp/
  Binary package           GStreamer Bad Plug-ins git
  Origin URL               Unknown package origin
3

Related issue: webrtcdsp: echo cancellation issue with stereo signal (#3220) · Issues · GStreamer / gstreamer · GitLab