[Ffmpeg-devel] MPEG-1 Decoder

Matthew Gertner matthew
Thu Sep 29 17:04:13 CEST 2005

Michel Bardiaux wrote:

> I have run the file thru a demuxer of mine that is designed to follow 
> the MPEG standard very strictly rather than be effective and 
> permissive as mplayer is. The diagnostic is clear:
> *** expect_bits: horoMpkCorruptionError: Expecting 0000 0000 0000 0000 
> 0000 0001 1011 1010 at bitpos 0, got 0101 0010 0100 1001 0100 0110 
> 0100 0110
> This is definitely not a standard MPEG-1 system stream (aka PS). How 
> was the file encoded in the first place?

I don't know. This is just a random file that was added to our testsuite 
to ensure that we can handle video files that are users might want to 
import into our software. If this is just an isolated case of a bad 
file, then it shouldn't be of much concern. However, it does seem to me 
that there is an argument for trying to handle files that are out there 
but don't conform strictly to the MPEG-1 standard. From Nico's comments 
it sounded like this might actually be quite common. We could go the 
route of using libmpeg2 as well as the ffmpeg libraries, like MPlayer 
does, but it would be preferable to keep dependencies on external 
projects to a minimum.


More information about the ffmpeg-devel mailing list