DGIndex: only YUV output, no RGB conversion

[varunb]

Is it possible to prevent the yuv to rgb conversion in dgindex while creating a d2v file ? If its not can this option b incorporated in newer versions of dgindex ? cos i do most of my work in yv12 only & unnecessary conversion(yuv->rgb->yuv) causes some quality loss in color.

[squid_80]

AFAIK it only decodes to RGB if you use the upConv parameter in your mpeg2source line. That is, unless you're frameserving with VFAPI in which case the conversion to RGB is unavoidable.

[varunb]

upconv parameter ? Sorry squid_80 but i didn't understand what u were trying to say.

[Didée]

How do you come to the conclusion there would be a YUV->RGB conversion happening?

the yuv to rgb conversion in dgindex while creating a d2v file
During creation of the d2v file, sure as anything there is no conversion happening. DGIndex does what it's name says: it's writing an index. Thats all.

Later on in the Avisynth script, decoding is done by DGDecode.dll ("Mpeg2Source()"). Here you have the possibility to decode the source to RGB, by adding "upconv=true" to the source() call. "upconv" is defaulted to "false", so if it is not explicitely specified, decoding will be done to native colorspace of the source (usually YV12), without conversion.

In case you're working with an application that's using the Stoneage VFAPI interface, conversion to RGB can't be avoided, like squid_80 noted. (What in that case should be avoided is ... the application.)

[check]

You aren't thinking of the iDCT algorithm are you? This, at least, is completely unrelated to RGB/YUV. Read more in the manual: DGIndexManual.html#iDCT_Algorithm