Hello.

I ran into a similar issue when trying to retrieve a remote audio stream via 
PeerConnection, filter it through web audio, and then send the resulting stream 
to another peer. I know I may be asking for too much conjecture, but do you 
have any kind of time frame for when this issue might be fixed? Alternatively, 
is there a good workaround I can try (note: it has to be in Firefox)? Thank you.

On Thursday, January 9, 2014 11:21:50 AM UTC-5, Randell Jesup wrote:
> On 1/9/2014 8:29 AM, [email protected] wrote:
> 
> > I am developing a multi peer audio conferencing software (of sorts) and 
> > since using the Web Audio API handles playback better (faster) than an HTML 
> > 5 audio element. I would like to use it. Firefox is currently supporting 
> > Web Audio (AudioContext) and so I am working on migrating my software over 
> > to playing back both local and remote streams using AudioContext for 
> > Firefox (because Chrome does not support "createMediaStreamSource" on 
> > remote streams... yet)
> 
> >
> 
> > Additionally, for those browsers that support WebRTC and Web Audio we give 
> > them the possibility to use effects (such as distortion and reverb) on 
> > their stream. Here is where I am running into problems and I can't find 
> > exactly where the problem lies... so I'm having difficulty in coming up 
> > with a solution.
> 
> >
> 
> > If a peer using Chrome(31) sends a stream that has effects applied to it 
> > using Web Audio both Firefox(26-29) and Chrome can playback the stream. If 
> > a peer is using Firefox and applies effects using Web Audio neither can 
> > playback the stream.
> 
> >
> 
> > There is no apparent difference in SDP offers/answers. The only real 
> > difference, that I discovered, is that the Firefox stream taken directly 
> > from getUserMedia is labeled as [object LocalMediaStream] and if I pass it 
> > through AudioContext it is then labeled as [object MediaStream]... even 
> > after using "addStream" to set it as my local stream when setting up the 
> > peer connection.
> 
> 
> 
> To reduce latency and avoid latency buildup in clock rate mismatch cases 
> 
> between the internal streams and the microphone input, audio going from 
> 
> a getUserMedia MediaStream (LocalMediaStream) to a PeerConnection 
> 
> 'bypasses' the MediaStreamGraph itself (PeerConnection uses direct 
> 
> notification of data being added to the stream as its source, instead of 
> 
> the processed output of the stream).  This needs to be fixed for cases 
> 
> where the stream added to the PeerConnection isn't a LocalMediaStream, 
> 
> though that also means that there's a possibility that microphone 
> 
> sources processed with WebAudio will drift (more delay or occasional 
> 
> underflows/glitches), which also needs to be resolved with resampling 
> 
> (bug 908834 and 818822)
> 
> 
> 
> I filed a bug to track this, bug 958090.  Note that while it can be 
> 
> fixed on it's own, as mentioned it will cause problems when used until 
> 
> the resampling bugs are fixed.
> 
> 
> 
> -- 
> 
> Randell Jesup, Mozilla

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