WMV9 - Colorspace conversion

[Stavr0s]

Hi,
does anyone know the colorspace conversions with which the WMV9-codec works? The standard just mentions that VC-1 uses Y Cb Cr, but not how the actual conversion RGB->YUV happens. I found a link http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dnwmt/html/yuvformats.asp which mentions the two possible ITU Rec.'s (601 and 709) and in which case they 'should be considered the preferred format', but it doesn't acknowledge if that's what Microsoft uses themselves in the Windows Media Encoder.

On another note, is it possible to make the RGB->YV12 conversion in advance and force WMV9 to accept this?

Thx,
Steven

[lcx]

The standard says that 709 is the default value.

Can't you use HuffYUV for the encoder input?

[Stavr0s]

Thanks for your answer. It made me dig through the SMPTE-draft again and finally I think I found the relevant passage. The chromacity coordinates for color primaries (this is something opto-electronic) are defined as in ITU-R BT. 709-5, but the MATRIX_COEF-element (which defines the color conversion) is defaulted to ITU-R BT. 601-5 (although 709-5 should be possible).

I was planning on using the ffdshow-huffyuv (in YV12-mode), but I just wanted to be certain that the WM Encoder doesn't perform any other internal color conversion. I guess (and hope) it doesn't.

Thanks again,
Steven