YUV Mixing ModeI used the Video Mixing Renderer 9 to test this. Needed the mixing renderer to support input from multiple pins, one movie and one subtitles. That did work. To be honest I've not checked the complete graph pins to check output though. I do know the movie was YUV, I double checked the output of the VobSub filter and it's mediatype was ARGB32.But did you try it with EVR or VMR9 (with YUV mixing mode enabled, not sure if this can be enabled in GraphEdit) as video renderers?? I'm not sure what you mean by that? I tried it in graphedit and the alpha thing did work, blending the subtitles over the movie.
# The other inputs pins can only accept per-pixel alpha YUV formats, such as AYUV, AI44 and IA44.
# None of the VMR's input pins can accept any RGB formats.