what is difference XviD 12 bit, 24 bit?

[blackdiamond]

I encoded movie using Koepi Xvid codec.
AVI header says: XviD MPEG-4 codec, 12 bit
Other movies I have says: XviD MPEG-4 codec, 24 bit

What is the difference?

[mf]

Simply a header issue. Both are 12-bits. Search the forum for it.

[drebel]

If other movies are in fact older movies ,this could also mean YUY2 colorspace with older avisynth versions, no?

[Assault]

I think it doesn't matter if there are any colorspace conversions during the encoding process. All mpeg4 codecs save the data internally as YV12.

Assault

[mf]

Originally posted by drebel
If other movies are in fact older movies ,this could also mean YUY2 colorspace with older avisynth versions, no?
Assault is right. It's always YV12 and thus it's always 12bpp. Simple as that.

[unmei]

agree. but if the avi header says 12 it means VDmod used fast repack mode else it would get higher numbers. 24 means the file was encoded in full processing (probably VD filters). Well this is just what i saw from my files , could be other people's setup behave differently.

[Acaila]

There are actually more scenarios:

VDub on fast recompress, Avisynth version 2.0x --> 16 bit (because VDub gets fed 16 bit YUY2 data)
VDub on fast recompress, Avisynth version 2.5x --> 12 bit (because VDub gets fed 12 bit YV12 data)
VDub on full processing --> 24 bit (because VDub uses 24 bit RGB, this is also the case for DivX 3 videos made through Nandub)

But in all cases it's the codec that determines the actual color depth, not the program you use to encode.

[drebel]

Thx Acaila.That's the bit value I couldn't remember correctly.It's been a while since we stopped messing with YUY2 and RGB,isn't it? :D