Colors Are Darker Converting from MPEG2 to XVID

[Soopafresh]

Apologies if this has been asked before, but is there a way to accurately compensate for the color shift ? I know there are brightness/contrast controls and plugins for Vdub, but is there an automatic way to fix it ?

TIA

[celtic_druid]

There shouldn't be any colour shift. If you are using VDub filters though then you are converting to RGB24 which could be the cause. Use AVISynth so as to keep the entire process in YV12.

Another possibility is that it is purely a playback issue. For instance a video displayed via a hardware overlay might look darker or lighter than one using a software overlay, etc.

[Soopafresh]

Thanks, Celt. I've been playing around with some Avisynth settings and it seems to be more accurate.

ColorYUV(levels="PC->TV") seems to help when it is in the AVS script.

Man, once you learn a little, you realize how much you don't know.

[ulapines]

I have the same experience.
Using various tools with same xvid settings, when converting to xvid always yields same results e.g. darker color.
No optional filtering.
Both mpeg2 and xvid files are played back on computer with Media Player Classic.

Is this some shortcome in XVID codec?

[celtic_druid]

If you feed XviD YV12 then it will output YV12 at the same colour levels. It doesn't change them.

Converting to RGB24 and then back to YV12 may all effect brightness.

Playing two files at once may also effect brightness as one uses a hardware overlay and the doesn't.

Not exactly related, but XviD by default outputs YUY2 and the internal upsampling is not the best. Shouldn't effect brightness though, but you may get some artifacts.