I have a question about YUV processing in Premiere Pro, especially about the blending modes.
Does Premiere Pro process blending modes on two YUV clips in YUV color space, or does it perform YUV->RGB->YUV conversion, and all the blending happens to be in RGB?
Also, if such a conversion is taking place, what matrix is being used for YUV->RGB conversion? REC601 or REC709? If both, then how is the choice determined?
Thanks for your help.
It depends on the blending mode. Normal compositing may be done in either RGB or YUV, but the more artistic blend modes are done one RGB. Converting from YUV will be done from either Rec601 or Rec709 depending on the encoding with which the source tagged its data for that layer.