[Live-devel] wrong timestamping for MPEG-4 ES

[Ross Finlayson]

>for a MPEG-4 video stream, generated with ffmpeg,  we found out that 
>the timestamps were not generated always correcctly. The timestamps 
>are not increasing monoton.

Note that - if the video contains "B" frames, then the frames' 
presentation times - and thus the RTP timestamps - will not be 
increasing monotonically.  This is expected.

>Without having fully understood the parsing of the MPEG-4 stream, I 
>found out that the problem disappeares when the variable 
>fPrevNewTotalTicks is reseted when a new time code is parsed from 
>the file. (see code below)

The "fPrevNewTotalTicks" variable is intended to detect (and, ideally 
correct for) certain types of buggy MPEG-4 video streams.  Perhaps 
your stream is buggy in this way??  You can detect this by adding
         #define DEBUG 1
to the start of "MPEG4VideoStreamFramer.cpp", and recompiling (after 
reverting the change that you made).

If the debugging error messages don't help you, then please place a 
copy of your MPEG-4 Elementary Stream video online, and send us the 
URL, so we can take a look at it.


	Ross Finlayson
	Live Networks, Inc. (LIVE555.COM)
	<http://www.live555.com/>