[Galene] Re: Experimental outbound activity detection

[Juliusz Chroboczek <jch@irif.fr>]

> I was trying to understand what's missing for outbound activity detection
> (aka "Is this thing on?"), and learned that there is a "totalAudioEnergy"
> property for outgoing WebRTC streams as well, but it's not yet implemented
> in Firefox:
> https://developer.mozilla.org/en-US/docs/Web/API/RTCAudioSourceStats/totalAudioEnergy

Yes.  Firefox's support for WebRTC is unfortunately incomplete, there are
a number of workarounds in the code for Firefox's bugs.  I really need to
check if they are still needed in recent versions (and display a warning
if the user is running an old version of Firefox).

A workaround would be to push the output through a WebAudio component,
I hear that WebAudio is well supported under Firefox.  I don't know if it
would increase CPU usage by much.

(WebAudio is a lot of fun, by the way, it's what's used on the login page
for the Fourier transform.  It could be used for implementing audio
filters, it's extremely flexible if you don't care about CPU and battery
usage.)

> https://github.com/jech/galene/compare/master...alxndr42:galene:outbound-activity

I don't think you need maxAudioEnergy, there should be only one audio track.

> It does seem to work in Chromium, using largely the existing code. Here's
> an experimental branch, please let me know what you think:
> https://github.com/jech/galene/compare/master...alxndr42:galene:outbound-activity

I haven't looked yet, but one thing comes to mind: we currently use
different intervals for up and down stats, so the appearance will be
different.  Should we make the intervals equal, now that the up connection
stats are no longer visible by default?

> So right now the code detects no activity in Firefox, but "should" start
> to work if they eventually implement the missing parts.

Don't count on it.  I fear there's nobody working on WebRTC at Firefox.

-- Juliusz