Gerd Knorr (kraxel@xxxxxxxxxxx): > > > Just use 4:2:2 and skip the chroma scanlines you don't want. > > > > Why is it that the bt848 can't just be programmed to skip the > > appropriate scan lines? That would be more efficient. > > [...] > > And how exactly the interleave should look like? One chroma scanline > is used for two luma scanlines, one from the even field and one from > odd field. No matter whenever I use the even or odd field for the > chroma scanline, it would match for one of the two luma scanline only. > I can make the bt848 interleave chroma too, but I don't see how this > improves the situation. It is still wrong for 50% of the luma > scanlines. If you're not filtering and instead just dropping scanlines, well, this sucks. However, it's better than dropping the chroma completely for the other field. Let me describe what I'd like. Say we have 4 scanlines (a,b,c,d). Let field 1 be (a,c) and field 2 be (b,d). I want chroma from (a,b) instead of (a,c). That way, I can look at each field as a separate image and have correct colour. Again, this is important when recompressing to formats such as MPEG which use 4:2:0 sampling. If I play back a field-encoded MPEG2 stream, it looks really really messed up if every second frame displayed has the colour wrong. -Billy -- Billy Biggs vektor@xxxxxxxxxxxx
