[FFmpeg-devel] RTP mark bit not passed to parse_packet

Alexandre FERRIEUX - FT/RD/SIRP/ASF/SOFTL alexandre.ferrieux
Thu Jan 15 18:53:45 CET 2009

Michael Niedermayer wrote:
>>>> However, I'm still struggling to understand why the command:
>>>> doesn't even create "out.263" nor prints any of the hex dumps...
>>> a few printf()/av_log() should tell you where it gets stuck an why
>> See my answer to Luca: we never get past av_find_stream_info, never 
>> calling my code. Please answer there.
> the thing is ffplay/ffmpeg file.h263 has to get past it if it plays the file,
> what is different?
> A few printf/av_log in av_find_stream_info() should show what is different ...

Indeed, thanks !

Further investigation (printing the incremented counter of frames in 
av_find_stream_info()) shows that it takes a fairly large number of 
frames to decide, unless an EOF occurs I guess. But in RTP/UDP there's 
no EOF of course, and I was repeatedly streaming the same short 
sequence, so when the seqnum/timestamps had a discontinuity, maybe the 
guessing work was reset...

Anyway, streaming a longer sequence works.

A few ancillary questions:

1) This means all those frames are accumulated in memory, right ?

2) What extra info could I have provided (eithr in the SDP or in 
command-line options) so that this guessing work be avoided ?


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