[FFmpeg-devel] [PATCH] pngdec: set correct range

[wm4]

On Fri, 8 May 2015 10:30:34 +0000 (UTC)
Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> wm4 <nfxjfg <at> googlemail.com> writes:
> 
> > > > > I believe this is slightly misleading: gray8 and 
> > > > > gray16 are interpreted as full-range by default 
> > > > > since years.
> > > > 
> > > > Really? Where?
> > > 
> > > In the software scaler.
> > 
> > Doesn't matter much from the API user point of view. 
> > Not everyone uses libswscale.
> 
> As said, I had no objections against your patch (on 
> the contrary) but I wonder why you want to set a field 
> that is mostly useful when using libswscale if you 
> don't use libswscale.

Uh, what?

Do you think libswscale is the only thing that processes video?

> > There is the (unwritten?) convention that YUV is 
> > limited range, and RGB is full range. GRAY is 
> > somewhat both, but at least the pixdesc tables
> > do not mark it as RGB.
> 
> I don't think the issue is related to (current) 
> pixdesc but I may miss something.
> 
> > What is your opinion about this?
> 
> I committed part of the change making gray full range...
> 
> Whoever wants to use frame->data[0] should use it;-)

What do you even mean?

So what is the API user supposed to do? Special-case by codec? Just
what is it?