[MPlayer-dev-eng] Re: Problems playing non-MPEG streams using RTSP

[Ross Finlayson]

> > I'm still having trouble receiving GSM audio streams, however.  Can you
> > tell me what the various WAVEFORMATEX fields should be for GSM?
> >
> > (Recall that GSM compresses each block of 160 samples into a resulting
> > 33-byte frame, and that there are 8000 samples/second - so that each
> > 33-byte frame corresponds to 20 ms (i.e., 50 frames.second).)
> >
> > Here's what I've been trying:
> > wf->nChannels = 1;
> > wf->nSamplesPerSec = 8000;
> > wf->nAvgBytesPerSec = 1650;  // == 33*50
> > wf->nBlockAlign = 33;  // IS THIS CORRECT???
> > wf->wBitsPerSample = 16; // CORRECT??? - the samples have been compressed
> > wf->cbSize = 0;  // IS THIS CORRECT???
>
>hmm, they are ok for the standard GSM, but not the MS one.
>afair no standard gsm decoder in mplayer, at least not finished (xa_gsm
>contains the decoder). could you upload a .mov file using this format, so 
>i can
>fix it?

Yes, I've left a .mov file online as:
         http://www.live.com/mplayer/sample-gsm-8000.mov
(for the next day or two)
This contains two tracks.  The audio track is the only one of importance 
(that contains the GSM).
I've also left the raw GSM data online as:
         http://www.live.com/mplayer/sample-gsm-8000.gsm

I hope this helps!

         Ross.