[FFmpeg-devel] [PATCH] better detection of available streams for flv

[Michael Niedermayer]

On Mon, Apr 14, 2008 at 12:51:15AM +0200, Michael Niedermayer wrote:
> On Mon, Apr 14, 2008 at 12:09:03AM +0200, Reimar D?ffinger wrote:
> > On Sun, Apr 13, 2008 at 09:19:40PM +0200, Michael Niedermayer wrote:
> > > On Sun, Apr 13, 2008 at 09:04:52PM +0200, Reimar D?ffinger wrote:
> > > > On Sun, Apr 13, 2008 at 07:57:44PM +0200, Michael Niedermayer wrote:
> > > > > On Sun, Apr 13, 2008 at 06:06:00PM +0200, Reimar D?ffinger wrote:
> > > > > > Hello,
> > > > > > with e.g. http://eurovision.tv/upload/video/2008/WELCOMETOBELGRADE.flv
> > > > > > the flv demuxer thinks that there is no video stream.
> > > > > > Attached code changes the code to create a audio/video stream if the
> > > > > > metadata-parsing code finds a key starting with "audio" or "video" and
> > > > > > there is not yet such a stream.
> > > > > > Obviously, there are many other ways to do this, and if such a change is
> > > > > > done the hack in flv_read_header should probably be removed.
> > > > > > Instead of checking for any key starting with audio/video this could of
> > > > > > course be restricted to those we actually handle, namely audiocodecid,
> > > > > > videocodecid, audiosamplesize, audiosamplerate and stereo.
> > > > > 
> > > > > We support flv with invalid headers since r10887. Which does not depend on
> > > > > metadata. Why does this not suffice?
> > > > 
> > > > I think you mean the hack in flv_read_header?
> > > 
> > > no i mean:
> > > 
> > >     if(i == s->nb_streams){
> > >         av_log(NULL, AV_LOG_ERROR, "invalid stream\n");
> > >         st= create_stream(s, is_audio);
> > >     }
> > > 
> > > that is if this packet belongs to a stream which we dont have create it.
> > 
> > I have no idea how this is supposed to work even remotely, the metadata
> > that contains the codec id etc. is long past and has been ignored.
> 
> The metadata is not needed to identify the codec.
> grep for flv_set_video_codec
> 
> 
> > It might also not work well if the second stream starts rather late in
> > the file, I doubt all lavf users can handle a stream appearing during
> > playback well.
> 
> av_find_stream_info() will check if the demuxer can add streams later
> (AVFMTCTX_NOHEADER) and if so preread a little.

> Though i see now AVFMTCTX_NOHEADER is missing in flvdec.c ...

And that was why it didnt work
problem fixed :)

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

I hate to see young programmers poisoned by the kind of thinking
Ulrich Drepper puts forward since it is simply too narrow -- Roman Shaposhnik
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