[Libav-user] Questions about ColorSpace conversion in swscale
Carl Eugen Hoyos
cehoyos at ag.or.at
Mon Aug 18 19:39:57 CEST 2014
Markus Pfundstein <markuspfundstein86 at ...> writes:
> Assume I have YUV422 BT 601 input and I want my output
> to be YUV444 FullRange. Is this possible without telling
> SwsContext that my input source is BT 601?
How is this supposed to work?
(Assuming libswscale is a black box and without discussing
its internals: How would it know what you want if you
don't set the appropriate options?)
> Also, does swscale first transform the input color
> space to XYZ and then transform it further into the
> target color space?
(Sorry if I misunderstand XYZ)
This sounds very slow, some conversions use yuv420p as
intermediate format (this is what is generally needed
for video). It is possible to use yuv444p instead, at
least for some conversions.
> And why is there no yuv2rgb function but only a
> rgb2yuv function?
I believe many such functions exist.
> If I want my output color space to be rgb, such a
> function would be needed or not?
Does yuv->rgb conversion not work for you?
I cannot answer some of your questions: If no 16 bit
path exist for a conversion you need, it should be
possible to add it but currently your information
about what you need is very vague.
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