PDA

View Full Version : Why isnt there a luma-inverted block checker?


Zarxrax
21st February 2002, 21:22
Why hasn't anyone out that made a program that can check a divx for luma-inverted blocks yet? It seems like it would be pretty easy to do...
Just have it take the source video, and convert each frame to a luma-inverted state. Now compare this luma-inverted frame to the original, and discard any blocks that are the same. Now compare the blocks in this frame to the frame of your divx encode. If any blocks match, then its writes the frame number into an ecf file for you to reencode with.

-h
25th February 2002, 14:30
Whilst I'm not familiar with the codec's internals, it sounds like this problem is just a simple coefficient range issue, or motion vector range bug. It should be possible to alter ffmpeg so that it scans a DivX 3.11 encode for any frames which have bad values and flag them automatically. Much much faster than comparing with the source.

But I have no spare time :(

And I also think it's easier to just use a codec which doesn't have such problems ;)

-h