On Sun, Apr 17, 2016 at 09:41:32PM +0300, Jan Ekstrom wrote: > On Sun, Apr 17, 2016 at 9:21 PM, Reimar Döffinger > <reimar.doeffin...@gmx.de> wrote: > > In particular, I have an uncomfortable suspicion that > > PGS might be designed to match the movie's colour space, > > in which case neither variant would give correct results > > but instead it would have to depend on what format the > > corresponding video track uses (and it probably would > > be more than just the 255/224 factor that would differ). > > Yes, the YCbCr values in palettes are matched accordingly against the > video stream. As per the specification: > "Y, Cr and Cb shall have the same color matrix as the associated HDMV > Video stream: 525-60/625-50 (Rec.601); 1080i, 720p (ITU-709)" > > Otherwise the specification notes that valid values in palettes are: > -Y: 16-235 > -Cr: 16-240 > -Cb: 16-240
?!??? These two kind of contradict each other, at least if the HDMV video stream uses a full range color matrix (or is that not allowed?). However with that additional information about the valid ranges I believe Carl's patch is correct, though we are not handling the exact coefficients correctly. As I don't really expect PGS to be used much with PAL/NTSC resolution, using ITU-709 would probably be a safe assumption in practice. I think the PGS stream does however contain the movie resolution, so switching between Rec.601 and ITU-709 based on that should probably be possible. In which case the dependency on the video stream does not really exist in practice. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
