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

Carl Eugen Hoyos cehoyos at ag.or.at
Fri May 8 12:30:34 CEST 2015

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.

> 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;-)

Carl Eugen

More information about the ffmpeg-devel mailing list