[Cin] threaded swscale in blender

[Andrew Randrianasulu]

вс, 27 апр. 2025 г., 20:55 Andrew Randrianasulu <randrianasulu at gmail.com>:

> Interesting diff, may be cingg can use something like this for speeding up
> swscale conversions?
>

another link from Blender:

https://projects.blender.org/blender/blender/pulls/116008

====

Whenever movie frame encoding needs to be in non-RGBA format (pretty much
always, e.g. H.264 uses YUV etc.), the ffmpeg code has been using
sws_scale() since 2007. But that one is completely single threaded.

It can be multi-threaded by passing "threads" option to SwsContext (in a
cumbersome way), combined with sws_scale_frame API. Which however requires
frame data buffers to be allocated via AVBuffer machinery.


===


and indeed, simple replacing of sws_scale by sws_scale_frame() in our
ffmpeg.C broke it ;)




>
> https://projects.blender.org/blender/blender/pulls/116309/commits/4647c80f52ead89524e429584c517831a5f6f04c
>
> But it seems that only upcoming ffmpeg version will allow to set transfer
> characteristics directly on avframe during scaling.
>
> So may be until this day our colorspace plugin should grow some knowledge
> about various gamma systems and also white points?
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.cinelerra-gg.org/pipermail/cin/attachments/20250427/a19c2dce/attachment.htm>