We should report echo levels in the AEC. Note that calculating them can cost CPU; so we don't want to blindly enable this all the time. We need to consider what the options are. Also, it can take a while to get results after enabling. Right now, I've made it depend on NSPR_LOG_MODULES=mediamanager:5 -- we likely should change this. Currently the patch I have dumps the stats once every few second or so. We should add it to about:webrtc (note: this will be complicated by the cost of measuring it/enabling/etc)

I did some profiling, and on a debug build it used <0.1% of the CPU used in an audio-only call on linux ... i.e. very little, so we can likely leave it on. On the downside: it is *very* hard to interpret ERLE in a vacuum; it depends heavily on the input signals, noise, volume, etc. So telemetry on ERLE may be very hard to interpret/misleading. Also, if used with telemetry we'd want to segregate it so headphone and speakerphone uses don't get mixed (we could segregate roughly based on ERL as a stand-in for knowing if it's a headset or not). Jean-Marc - do you know any good automated metrics beyond ERL/ERLE we could use? I'll also consult my Voice Quality for mobile book by Perry.

I think ERLE is probably a good metric here. OTOH, ERL is completely meaningless. The problem is that turning the volume up by X dB on your external speakers while turning it down X dB in the mixer will increase the ERL by X dB even though nothing actually changed in practice. The only metric I could think of would be a signal-to-echo ratio (SER). Since the signal power is fixed, then the ERLE also happens to be the improvement in SER.

Comment on attachment 8394951 [details] [diff] [review] Monitor AEC echo levels (ERLE/etc) in gUM Review of attachment 8394951 [details] [diff] [review]: ----------------------------------------------------------------- lgtm, with the caveat that I haven't seen the patch that this patch depends on (there's no update_echo or mStarted in the tree), so bear in mind when landing. ::: content/media/webrtc/MediaEngineWebRTCAudio.cpp @@ +589,5 @@ > > +#ifdef PR_LOGGING > + mSamples += length; > + if (mSamples > samplingFreq) { > + mSamples -= samplingFreq; Is length ever > 2*samplingFreq? If so then you fall behind here. Maybe a while(>) -=, an assert, or mSamples %= samplingFreq?

Backed out for perma-orange on b2g emulator M10 unrelated to this patch https://tbpl.mozilla.org/?tree=Mozilla-Inbound&rev=cb894b5d342f http://hg.mozilla.org/integration/mozilla-inbound/rev/c0eaa844f2f0

Backed out of central: https://hg.mozilla.org/mozilla-central/rev/ac6cbaa47f34

backed out: https://hg.mozilla.org/integration/mozilla-inbound/rev/206169eef995