вт, 2 авг. 2022 г., 20:10 Einar Rünkaru <[email protected]>:
> Hi. > > On 02/08/2022 11:37, Andrea paz wrote: > > > Thanks for the responses; glad to hear from you again. > > In the CVE readme you mention the internal 16-bit color model. Since > > you remain the only deep Cinelerra expert (besides Adam, with whom it > > is difficult to interact), may I ask you to explain how color works in > > Cinelerra? Is it converted continuously as needed? > > Video is decoded to internal representation (look at settings/format). > Internal format is unpacked 3..4 values every pixel. CVE has only > RGBA-16 and AYUV-16 pixel formats. All values are 16 bit. > > CVO (and probably CGG) have 6 internal pixel formats (8-bit and float) > > > Does each plugin > > make the conversions it needs? > > All plugins see the frames only in internal format and modify this as > needed. > > > What do the color model settings affect > > and what are they affected by? > > Color model describes internal pixel format > > > Is it possible to implement ICC > > profiles? > > Probably. How? > Good question. I was looking into mplayer2's code for display part https://github.com/astiob/mplayer2/blob/all/libvo/vo_gl3.c Then I found news from yesteryear about lcms2 plugin https://littlecms.com/plugin/ "Little CMS floating point plug-in accelerates 8 bit and floating point color transforms, ".." The speedup is accomplished by implementing new interpolation kernels, adding optimizations and re-arranging memory layouts. Additionally, it can use SIMD instructions if present." Then there is new infrastructure in ffmpeg git: http://ffmpeg.org/pipermail/ffmpeg-devel/2022-July/299438.html https://git.ffmpeg.org/gitweb/ffmpeg.git/commit/61ffa23c2e42887b32d469d9e69e9eb887b29e9c "avcodec/codec_internal: add cap for ICC profile support" As far as I understand it only works with webp, tiff, png and mjpeg as video format but hopefully can be extended in future? > > In short, I am not clear about anything related to color > > treatment in Cinelerra. This is an issue that we have been dragging > > around for years (for example see the thread: > > > https://www.cinelerra-gg.org/forum/help-video/yuv-to-rgb-conversion-issues/ > ) > > but the confusion is total and we can't figure it out. > > Few mentions were made many years ago: > > https://lists.cinelerra-cv.org/pipermail/cinelerra/2018q4/009903.html > > https://www.mail-archive.com/[email protected]/msg13761.html > > Original Cinelerra does not care about colorspaces. It uses what comes > out from decoder. Some effects work differenlly depending on colorspace. > Sometimes pixel values are converted to float, sometimes to 8-bit for an > effect. Fixing it takes couple of man-years. > > CVE converts color to full-scale (0..65565). All effects work with full > scale values. Encoding converts to colorspace required by the codec. > > Einar > > PS Removed CinGG ML - it does not accept my mails - I am not subscribed. > > >
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