[FFmpeg-devel] [PATCH v7 06/12] swscale: organize and better document flags

[Michael Niedermayer]

On Thu, Nov 21, 2024 at 01:06:20PM +0100, Niklas Haas wrote:
> On Thu, 21 Nov 2024 01:26:36 +0100 Michael Niedermayer <michael at niedermayer.cc> wrote:
> > Hi
> >
> >
> > On Sat, Nov 16, 2024 at 12:25:01PM +0100, Niklas Haas wrote:
> > > From: Niklas Haas <git at haasn.dev>
> > >
> > > Group them into an enum rather than random #defines, and document their
> > > behavior a bit more obviously.
> > >
> >
> > > Of particular note, I discovered that SWS_DIRECT_BGR is not referenced
> > > anywhere else in the code base. As such, I have moved it to the deprecated
> > > section, alongside SWS_ERROR_DIFFUSION.
> >
> > The intend of SWS_DIRECT_BGR was to avoid a intermediate YUV
> > for RGB -> RGB rescaling. It indeed probably makes no sense in a new API
> > like that
> >
> >
> > "#defines" and enums are not exactly equivalent and could break some user apps
> > in theory
> >
> > I think its probably ok but maybe should be documented in APIChanges or something
> 
> I can add a note in APIchanges, but it feels a bit silly to bump the ABI version
> for this, since it's just a compile-time change. I propose:
> 
> 1) Add a note in APIchanges but without bumping the version
> -or-
> 2) Squash this commit in with the one adding the new API
> 
> In either case, I imagine the concern is largely theoretical, since the only
> realistic way I can imagine it breaking is if a user for some reason decided
> to #ifdef to see if a flag is supported (instead of looking at the version).

Its probably theoretical, but people do all kinds of stuff. Like building
wrapers around our API and I remember one of these once unexpectedly breaking
with some change unrelated to this.
So IMHO it should be documented, the details are less important

thx

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

There will always be a question for which you do not know the correct answer.
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