playing video backwards Re: [MEncoder-users] Quick question - advice appreciated

Dieter freebsd at
Wed Aug 2 10:15:28 CEST 2006

>  Is there any codec out there by itself that would be suitable for this? 
> If not, it's mine mine mine you hear me!! I call it! Patent patent 
> patent!  :D

The video part is trivial.  Convert to DV.  Seek to end (or whereever).
Display a frame.  Seek back 'n' bytes.  Display a frame.  Seek back 'n'
bytes.  Repeat.  'N' is constant in DV format, but different for NTSC vs PAL.

The audio is more difficult.  The method above will play it backwards,
sort of.  You'll get 1 frame played forwards, then the previous frame
played forwards.  Very very choppy.

You'd really want to reverse the audio one sample at a time rather than
one video frame at a time.  Pick a suitable format (PCM?) and lookup
where the sample boundaries are, reverse them, recombine with video.

Good luck having the video and audio in sync.  Sometimes the source
isn't in sync.

While you're at it, find out where they buried Paul.

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