[Live-devel] dump h264 video problem

[Ross Finlayson]

>]I've found an h264 video stream that I'm able to dump and play correctly
>rtsp://media.lscube.org/tests/tc.mov
>
>This one suffers the problems I was talking about:
>  rtsp://streaming1.osu.edu/media2/ufsap/ufsap.mov
>
>Both have been dumped with
>./openRTSP -t -d 20 -q
>command line (no fps and w/h has to be specified for firts one, for
>second none worked)

The second stream's video has width 320 pixels, and height 240 
pixels, so you should specify those if you're trying to record it 
using "openRTSP -q".  (I'm not sure about the frame rate.)


>I'm not sure about one thing. H264VideoFileSink class that inserts 4
>bytes long delimiter between NAL units, is used only when streaming not
>when receiving a strem, right?

Wrong.  Because it's a 'FileSink', it's used only when *receiving* a 
stream.  If "openRTSP" is used to receive a H.264/RTP stream normally 
- without using the "-q" or "-4"  options - then the 
"H264VideoFileSink" class is used for the output.  If, however, 
"openRTSP" is used with the "-q" or "-4" options, then a different 
'FileSink' class - "QuickTimeFileSink" - is used.  Because you're 
using the "-q" option, this is what you are using.


>If so, the problem must be container related (QuickTime or mp4 does't
>matter for me) not codec related, since libraries are just dumping an
>encoded stream that is not touched or modified when saved to a file (or
>printed to stdout) inside the choosen container...
>Am I totaly missing the point?

I'm not sure.  But the basic problem here is that the ".mov" (or 
".mp4") file format was very badly designed, and is especially 
ill-suited for what we are trying to do: Record incoming media 
streams into a file.  The "QuickTimeFileSink" class tries to do this 
as well as it can, but the basic flaws of the file format makes it 
difficult.  Nonethess, it's possible that the "QuickTimeFileSink" 
implementation can be improved, so feel free to take a look at it, 
and let us know if you have any suggestions for improvements/bug 
fixes.  Remember, You Have Complete Source Code.
-- 

Ross Finlayson
Live Networks, Inc.
http://www.live555.com/