Is the newest Virtualdub capable for BT.709 colors

[Stears555]

HI!

Is the newest Virtualdub capable for BT.709 colors?

Thank you for the reply!

[jagabo]

In general, no, it uses a rec.601 matrix to convert between YUV and RGB. It has some support for rec.709 but it doesn't seem to work properly (at least in version 1.10.3 that I'm currently using). If you go to Video -> Color Depth... you'll see "other..." at the bottom of the lists. If you click on those you'll get another dialog that lists rec.709 options. But with many of those as the Decompression Format VirtualDub crashes. And with (at least some) of those as the Output Format you'll get a complaint that VFW doesn't support that colorspace when you try to save.

On the other hand, in many cases it doesn't matter that VirtualDub doesn't explicitly support rec.709. If you use Fast Recompress mode, incoming YUV video passes through to the compression codec. If it was rec.709 coming in it's still rec.709 coming out (though the compression codec may not flag it as such). In Full Processing mode VirtualDub will use a rec.601 matrix to convert incoming YUV to RGB for display and filtering, but if VirtualDub is set to convert back to YUV it will use a rec.601 matrix again. If the incoming video was rec.709 it's rec.709 on output too -- but the colors you saw on-screen while working were wrong (rec.709 converted to RGB as if it were rec.601).

[Stears555]

Why do people use such a backward software? It is inconceivable!

[El Heggunte]

Why do people use such a backward software?

Because it's free.
Because it often is better than Avidemux.
Because not every noob is "incurable"

[sanlyn]

Well...I have fiddled with some Rec709 sources and used ColorMatrix to get it to Rec609 for RGB color work in VDub, then converted back to Rec709 in Avisynth for HD encoding. If RGB work wasn't required, I just used fast recompress. I don't know that ColorMatrix was the best method. Maybe others can suggest?

In early usage of TMPGEnc Video Mastering Works, I noticed that upsized rec601 input was encoded by that software to HD formats as BT709. So it appears that TVMW5 is automatically making that 601-709 conversion. Some of this is still new to me. I'm sure someone has some insight into the best ways of handling it.