[FFmpeg-devel] [PATCH]Fix pix_fmt detection in jpeg2000

[Carl Eugen Hoyos]

Nicolas Bertrand <nicoinattendu <at> gmail.com> writes:

> Le 17/07/2013 11:19, Carl Eugen Hoyos a écrit :
> > But imo, the important question are not valid
> > samples but why do you think that the decoder
> > should depend with its MCT decision on the
> > colour space (especially if the specification
> > does not mention colour space at all).
>
> Because, as MCT is defined, if the input color 
> space is YUV, there are no need to do the MCT.

Isn't this completely up to the encoder to decide?
(Unrelated to the fact that it probably makes no 
sense.)

> If the MCT is done with a YUV color space, we 
> will do YUV --> RGB --> YUV. so useless.

Or in other words:
If the encoder decided (because of an error or 
another reason) to run its yuv input through 
the RGB -> YUV conversion, wouldn't the MCT be 
necessary to produce correct output?

Carl Eugen