[FFmpeg-user] Another odd colourspace issue

[Phil Rhodes]

> I believe that the colour space is generally decided solely on the frame  
> size.

I'm pretty sure you're right; at least, I've never been able to exactly  
figure it out. Coders?

It is of course cack. This problem has been under discussion for quite  
some time and it is easy to define how the solution should work, although  
actually implementing it requires a proper transform-based colour  
management system to be grafted on to ffmpeg, which might have some fairly  
far-reaching implications (although it could also be fairly simple,  
depending on how ffmpeg is actually laid out internally, which is not  
information to which we have easy access).

I suspect the reasons it has not been fixed are as follows:

- Fixing it might be a pain
- It's an extremely common problem in software (particularly if you  
include studio/full swing issues) and therefore having this problem is not  
as stigmatised as it should be.
- Most of the software people who work on ffmpeg are not video engineers  
and don't have a very complete knowledge of this area, and don't really  
understand why it's a problem or how to solve it and certainly won't take  
advice from the likes of us, and finally:
- Well, you sort of get a kind-of picture that has, broadly speaking, red  
green and blue in it, give or take, so that's pretty much, more or less,  
roughly, okayish, isn't it?

Remember this stuff is used mainly to feed Youtube, where people just  
assume that oranges and reds going super-neon-bright is cool.

P