[FFmpeg-devel] [PATCH v1 3/6] swscale: Add explicit rgb24->yv12 conversion

[Michael Niedermayer]

On Tue, Aug 22, 2023 at 03:24:17PM +0100, John Cox wrote:
> On Mon, 21 Aug 2023 21:15:37 +0200, you wrote:
[...]
> >> I can get to simple bilinear without adding so much complexity that I
> >> lose the speed I need - would that be OK?
> >
> >Not sure simple bilinear is 100% clearly defined
> >I think it could mean 3 things
> >
> >1 2 1
> >  C
> >1 2 1
> >
> >or
> >
> >  1
> >  C
> >  1
> >
> >  or
> >
> >1 2 1
> >
> >3 6 3
> >  C
> >3 6 3
> >
> >1 2 1
> >
> >I think the 6 and 12 tap cases would produce ok results teh 2 tap not
> >Also maybe there are more finetuned filters for this specific case, i dont
> >know / didnt look.
> >Testing these probably would not be a bad idea before implementation
> >
> >I think users in 2023 expect the default to be better than what the
> >existing code was doing by default
> >so feel free to replace the existing "identical" code too
> 
> I was thinking of 2-tap (in both X & Y) which is equivalent to
> SWS_FAST_BILINEAR in ffmpeg. In the case I'm looking at I need the speed
> more than I need the quality and I'm quite happy to gate them behind a
> test for SWS_FAST_BILINEAR.

ok but maybe you want to still fix/add the higher quality C version too?
it would be almost the same code, just a different mix of source samples
iam asking as you are already working on this

thx

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

Dictatorship: All citizens are under surveillance, all their steps and
actions recorded, for the politicians to enforce control.
Democracy: All politicians are under surveillance, all their steps and
actions recorded, for the citizens to enforce control.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20230822/6f4df445/attachment.sig>