WebRTC AEC Tuning

Recent changes to the cubeb backend reduced latency, and this broke assumptions in the AEC setup code and caused high-volume echoes. bug 974537 fixed this and made it platform-specific, but more tuning may be needed.

If you have a problem with bad echo in a webrtc call please follow these steps: (Note: the pref is available on all versions even if not visible in about:config - just add it as new and start at a value of 50)

• Have the person *not* hearing their own echo (and who likely is not using a headset) do this:
  • Try halving the value of media.peerconnection.capture_delay and make a new call
  • If that didn't solve it, try setting it to 0
  • If that didn't solve it, try setting it to double the original value.

Remember: if you hear an echo, the problem is at the other person's end!

Once you've either resolved the issue or given up, Please update bug 974537 with your results, and as much detail on your hardware and software setup as possible.