вт, 3 сент. 2024 г., 21:36 Andrew Randrianasulu <[email protected]>:
вт, 3 сент. 2024 г., 21:10 Andrew Randrianasulu <[email protected]>:
вт, 3 сент. 2024 г., 20:13 Tarantas via Cin <[email protected]>:
Since you're already fighting color banding, the good thing is to 32-bit colors in Settings -> Format -> Color model: RGB(A)-FLOAT. Note this could slow down your playback and rendering.
Guys, hold on a second. Unfortunately I just discovered the RGB color model is required for this recipe. The YUV model causes big color shifts for an unknown reason. Moreover, I found JPEG mode completely incompatible with YUV color mode, even without any filters or hacks, and I lost the track of what's going on already.
Must be just a bug because nobody tested JPEG mode in years.
Could you please advise me any tool to detect shifts in color channels in order to compose a proper bug report?
one technique from
https://news.ycombinator.com/item?id=20037013
make all-white png in say gimp (so each point reads as 255 in all channels) then convert it via tool in question (cinelerra-gg in our case) then measure colour values during playback (via colorpicker).
it may be that bt709 conversion does not allow full range by definition? (comment from that thread).
you can also try non-default pix-fmt (non yuv420p) for final encoding ?
cingg use 4:4:4 non-subsampled YUV in YUV mode, may be swscale lib having trouble doing its job here?
I also found two possible sources of full range video -Playstation 5 (at least back in 2023) and some GoPROs and other modern h264 based cameras
https://forum.shotcut.org/t/questions-about-color-range/38647/3
https://github.com/HandBrake/HandBrake/issues/2561
but may be sticking with artificial images is easier for debugging full => full encoding, then with full = > limited conversion step added on top of that.
and a bit more, apparently (at least in 2021) ffmpeg's prores encoder was able to stuff full range yuv data, but official apple decoders might assume tv range anyway ... https://www.liftgammagain.com/forum/index.php?threads/full-range-or-head-ran... so, while prores in general might be good idea, for full range workflow it may not work with official decoders?
All I could do now is just to
screenshot the difference between the compose window and render results. -- Cin mailing list [email protected] https://lists.cinelerra-gg.org/mailman/listinfo/cin