hallo, i tried to play rgba video with alpha in gem. IOhannes proposed PNGA video, so i got one using 'ffmpeg -i %4d.png -vcodec png rgba_png.mov||' you can find it here (13Mb): http://kubriel.servus.at/uploads/rgba_png.avi
i tested [pix_film] enabling alpha with [alpha] without succes, background is not transparent. i tested video in resolume with nice transparent background result.
Jakub