backward compatiblity problem ?

[Maurizio]

A friend of mine today showed me a film made
the 10 May 2002.
In such days the film was completely enjoyable, now
it's horribly covered by randomly colored blocks, 16x16 pixels,
making it completely unviewable.
Such blocks appear only in delta frames, not in key frames.
(Verified with VDub).
The problem exists on several other films, made few days after.
I've seen it also on my own comp, using the last stable version
of XVid and ffdshow.
My friend made any possible test, removing and reinstalling xvid, ffdshow,
Nic decoder, and so on, without being able to solve the
problem.
The only thing he didn't do was to reinstall an older version
of XVID. He will try this evening.
Anyone experiencing a similar problem ?
Any suggestion ?

Regards
Maurizio

[sysKin]

Perhaps interlaceing was used for this film?
Mpeg4 changed it's mind about interlaced bitstreams some time ago, and XviD had to change encoding/decoding rules.

Find a thread named "bad news for interlacing" (or something like this) in this forum.

Use ffdhow to decode this movie, and in it's configuration set Miscellaneous -> Workaround encoder bugs -> Old XviD interlaced bug.

Don't decode using XviD then (codecs-> use xvid off).

I hope it helps

Radek

[Maurizio]

Thank you very much.
Your suggestions solved my friend's problem.
Maurizio