What's the difference between MPEG-2 and H.263 quantization ?

[lovecraft25]

I looked into the WinME registry at [HKEY_USERS\.DEFAULT\Software\DivXNetworks\DivX4Windows] and I saw :
MPEG-2 Quantization = 0

So, it is possible to use MPEG-2 quantization with DivX 5...
But tell me why and when should I set "MPEG-2 Quantization" on ?
Has this any consequense on the size oh my AVI-files ?

[-h]

MPEG quantization in DivX 5 is not MPEG-4 compliant, due to a very very old bug which it seems will never be fixed.

The difference between MPEG and H.263 has been discussed quite a bit in the XviD forum.

-h

[lovecraft25]

Yes, but, even if it's not MPEP-4 compilant (I watch my DivX's on computers only), can I use it ? You say there is a bug...

[-h]

Yes, but, even if it's not MPEP-4 compilant (I watch my DivX's on computers only), can I use it ?

Of course. You just might have trouble playing it.

You say there is a bug...

There is an error in its rounding during dequant, I believe. It might not even be able to decode its own content, hence its presence as a registry hack.

-h

[lovecraft25]

Originally posted by -h

Of course. You just might have trouble playing it.

-h [/B]

I'tried to encode a movie : no problem during encoding, but the playback was slow-motioned : it was like a 20 FPS movie... Doh !
So, I will never use MPEG-2 quantization...