[FFmpeg-devel] [PATCH 01/24] avcodec: add color_range to AVCodec struct

[wm4]

On Wed, 2 May 2018 17:49:05 +0100
Rostislav Pehlivanov <atomnuker at gmail.com> wrote:

> On 2 May 2018 at 17:39, wm4 <nfxjfg at googlemail.com> wrote:
> 
> > On Wed, 2 May 2018 13:44:48 +0200
> > Nicolas George <george at nsup.org> wrote:
> >  
> > > Vittorio Giovara (2018-05-01):  
> > > > Well no, let's step back a little.
> > > >
> > > > First of all there is no stigma about adding fields to AVCodecContext,
> > > > in fact, the more, the merrier, right?
> > > >
> > > > Secondly, there _is_ concern about adding a field to AVCodec (not  
> > avctx),  
> > > > since is a delicate point of entry, and very sensitive to ABI (which  
> > in fact  
> > > > was broken in the first iteration of this patch).
> > > >
> > > > Finally, I immensely disagree that this is a good API at all, just  
> > throwing  
> > > > fields to structure is rarely a good approach to anything. On a  
> > separate note  
> > > > I also disagree that color_range (despite its importance) is an  
> > "essential  
> > > > property of images", at least not any more than the other color  
> > propeties:  
> > > > it is simply being noticed because there are special purpose enum  
> > values, but  
> > > > that doesn't mean that the other properties will work "just fine".  
> > Because  
> > > > they don't.
> > > > The transfer characteristics for example is a much more impactful and
> > > > delicate property that can affect the the color of the image in a much
> > > > more profund way than color range.
> > > > Similar arguments could be made for primaries and matrix.
> > > >
> > > > As much as you may hate hear it, this proposed filtering system does  
> > *not*  
> > > > belong to neither lavfi, lavf or lavc, but rather to the scaling  
> > library.  
> > > > Unfortunately the one used by default, swscale, is a monster spaghetti  
> > code  
> > > > and too difficult to work around. That however should not affect the  
> > design  
> > > > of APIs used in the other libraries: if swscale is not suited anymore  
> > for  
> > > > its job it should be replaced, you shouldn't be adding workarounds to  
> > AVCodec.  
> > >
> > > Thanks for taking the time to express the reservations. I fully agree
> > > with what you wrote.  
> >
> > Please don't prevent us from fixing libavfilter.
> > _______________________________________________
> > ffmpeg-devel mailing list
> > ffmpeg-devel at ffmpeg.org
> > http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> >  
> 
> 
> +1
> 
> also what Vittorio complained about (AVCodec fields) has NOTHING to do with
> lavfi or swscale.

Well, it sort of strides all components (my fault), but surely we don't
want to just stop solving this problem just because we have no
"perfect" solution.

Also this is the typical ffmpeg bikeshed brake: someone wants to solve
a small problem, others bikeshed it to death because they really want
to solve a much bigger problem that requires much more effort, and thus
doesn't get solved.