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
Then I found news from yesteryear about lcms2 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:
"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?