[MPlayer-dev-eng] Problem decoding a H.263+ stream

[Ross Finlayson]

Michael,

Thanks for taking a look at this.

> > The error is occuring in the call to get_vlc2() at line 2696 of
> > "h263.c".  This call is returning -1, which causes the macroblock decode to
> > fail, which subsequently triggers the error concealment code (which then
> > causes a crash, because this is the first frame, and there's no 'previous'
> > frame at this point).
>hmm, i thought i fixed that (first frame=NULL thing)

I just upgraded to the latest CVS version of "libavcodec", and still get a 
crash.  (I'm not sure yet if it's for the same reason, though.)

> > If you build the LIVE.COM libraries and "mplayer" (following the
> > instructions at <http://www.live.com/mplayer/>), and run
> >      mplayer -fps 15
> > rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov
> > you should see the error occur.
>doesnt seem to work, no audio/video shown at all, see attached log

I suspect that you're behind a firewall that is blocking UDP, in which case 
none of the audio or video packets will reach your computer.  To test this, 
try running
         mplayer rtsp://media.schreiner.edu/realmp3.mp3
which is known to work OK.  This should play a MP3 stream.  Please let me 
know if you hear the MP3 audio OK.  If you hear *no* audio, then you need 
to fix your firewall to allow UDP packets to pass through.

>and
>mplayer -fps 15
>rtsp://darwin.horizonlive.com:554/finlayson/sample-h263-ulaw-8000.mov -v
>-dumpstream crashed see attached log

Ahh - don't use "-dumpstream"; it won't work with a RTP stream, because - 
unlike other kinds of stream - there's no file descriptor sitting behind 
it.  That's probably what caused the crash.  (The "-cache" option used to 
have the same problem.)

         Ross.