Avidemux cannot deal with changing a/v sync, that is correct.
        At least with MPEG2 files?


        My question is, what exactly is rebuilding the B-frames doing?
Is it avidemux's way of generating the indexing offset information on a
per-GOP basis?  It's certainly not manipulating the actual video stream,
is it?

Avidemux needs to know if a frame is I, P or B. For mpeg it is written in the index file For avi, it uses an unused bit in the flags section

Upon loading the mpeg_inside_avi file, it checks and sees that some frames are B
frames but the index does not contain the flag saying it is a B frame.

Rebuilding the bframe quickly decodes each image (very fast for mpeg4, slow for
mpeg1/2), just enough to see if it is a P or B frame and updates the flags.

Good to know.... it's basically "rebuilding the index," but just for an AVI format (where it's contained within the file).

After that it can properly handle reordering and PTS/DTS sequencing.
HTH

So once it's an "mpeg in an avi" file, avidemux *can* handle changing PTS/DTS offsets then? If one were to export this out of avidemux as an MPEG_A+V, does it still have varying PTS/DTS offsets as the stream progresses or does it fix those?

Thanks!
-Cory

*************************************************************************
* Cory Papenfuss                                                        *
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University                   *
*************************************************************************



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