Re: [Linphone-developers] Mediastreamer newbie seeks clue.

[Herb Peyerl]

On Tue, Aug 31, 2010 at 11:45:21AM -0600, Matt Gilg wrote:
> I believe that generally, you need to create a new set of objects for each
> stream.  You can attach the streams to the same ticker, but you do need
> separate sessions & filters.  To create two streams and use them
> simultaneously, you'll also need to use a sound driver that supports the
> mixing of multiple audio sources.
>
> Hope this helps.

I must really be misunderstanding this ... It appears as though there's an 
audio mixer in mediastream2/src/audiomixer.c:

static void mixer_process(MSFilter *f){
 .
 .
 .
}

which appears to be able to sum linear PCM streams:

static void accumulate(int32_t *sum, int16_t* contrib, int nwords){
        int i;
        for(i=0;i<nwords;++i){
                sum[i]+=contrib[i];
        }
}


...and it also looks like oRTP is able to manage multiple RTP sessions using 
multiple RtpSession* objects with a custom select() ...

I think it should be able to mix multiple RTP sessions together and present a 
single unified LPCM stream to Alsa...

So it seems all the pieces are there but my little brain is failing to see how 
to put them all together ...