[MPlayer-users] Re: Bugs in MPEG-2 pack header and system header

[Alex Beregszaszi]

Hi,

> I ran a VOB file through an MPEG-2 stream analyzer and found some errors 
> in the headers, specifically the pack header and the packet header.  The 
> packet header bug is that the stuffing bytes appear in the wrong place. 
>    They should be just before the payload, not in the middle of the 
> header. Note: the stuffing is correct for MPEG-1.  If you play back the 
> VOB in RealPlayer, you'll see the effect -- a frame will be dropped and 
> the video jerks.
> 
> There are 2 pack header bugs for MPEG-2.  One is an extraneous marker 
> bit following the MPEG-2 clock extension field.  The other is a missing 
> marker bit right before the reserved field.  These bugs cause no 
> playback error; however, they cause an MPEG-2 stream analyzer to 
> complain that the mux rate exceeds the rate bound in the system headers.
> 
> If anybody is interested, let me know and I'll send you a patchfile for 
> libavformat/mpeg.c.  Maybe someone from the developer's list??
Subscribe to ffmpeg-devel and post those patches there.
Maybe these could fix some VCD/SVCD creation issues.

--
alex