Re: [FFmpeg-devel] [FFmpeg-cvslog] swscale: use 16-bit intermediate precision for RGB/XYZ conversion

[Michael Niedermayer <michael@niedermayer.cc>]

[-- Attachment #1.1: Type: text/plain, Size: 2620 bytes --]

Hi

On Sun, Jan 26, 2025 at 07:26:59PM +0100, Michael Niedermayer wrote:
> On Thu, Dec 26, 2024 at 07:33:23PM +0000, Niklas Haas wrote:
> > ffmpeg | branch: master | Niklas Haas <git@haasn.dev> | Mon Dec 16 14:49:39 2024 +0100| [af6d52eec66961f6a502b0f2f390c12226d087cd] | committer: Niklas Haas
> > 
> > swscale: use 16-bit intermediate precision for RGB/XYZ conversion
> > 
> > The current logic uses 12-bit linear light math, which is woefully insufficient
> > and leads to nasty postarization artifacts. This patch simply switches the
> > internal logic to 16-bit precision.
> > 
> > This raises the memory requirement of these tables from 32 kB to 272 kB.
> > 
> > All relevant FATE tests updated for improved accuracy.
> > 
> > Fixes: #4829
> > Signed-off-by: Niklas Haas <git@haasn.dev>
> > Sponsored-by: Sovereign Tech Fund
> > 
> > > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=af6d52eec66961f6a502b0f2f390c12226d087cd
> > ---
> 
> this breaks on x86-32

ping

the fate tests for a major architecture are broken since this
This impacts future bisections over that range for example

you can trivially test this on x86-64 with something like:
--cross-prefix=/usr/i686-linux-gnu/bin/ --cc='ccache i686-linux-gnu-gcc-7' --arch=x86_32  --target-os=linux --enable-cross-compile
if you have the correponding packages installed

before af6d52eec66961f6a502b0f2f390c12226d087cd
TEST    filter-pixdesc-xyz12be

after af6d52eec66961f6a502b0f2f390c12226d087cd:
--- src/tests/ref/fate/filter-pixdesc-xyz12be	2025-03-14 00:46:40.445681223 +0100
+++ tests/data/fate/filter-pixdesc-xyz12be	2025-03-14 00:47:08.301903796 +0100
@@ -1 +1 @@
-pixdesc-xyz12be     1508a33dea936c45d9ee13f7743af00d
+pixdesc-xyz12be     198f43f452bc55f4ca1e0e0171de5c4c
Test filter-pixdesc-xyz12be failed. Look at tests/data/fate/filter-pixdesc-xyz12be.err for details.
make: *** [src/tests/Makefile:311: fate-filter-pixdesc-xyz12be] Error 1

in master:
--- src/tests/ref/fate/filter-pixdesc-xyz12be	2025-03-14 00:46:40.445681223 +0100
+++ tests/data/fate/filter-pixdesc-xyz12be	2025-03-14 00:48:43.042660972 +0100
@@ -1 +1 @@
-pixdesc-xyz12be     1508a33dea936c45d9ee13f7743af00d
+pixdesc-xyz12be     198f43f452bc55f4ca1e0e0171de5c4c
Test filter-pixdesc-xyz12be failed. Look at tests/data/fate/filter-pixdesc-xyz12be.err for details.
make: *** [src/tests/Makefile:315: fate-filter-pixdesc-xyz12be] Error 1


thx

[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Never trust a computer, one day, it may think you are the virus. -- Compn

[-- Attachment #1.2: signature.asc --]
[-- Type: application/pgp-signature, Size: 195 bytes --]

[-- Attachment #2: Type: text/plain, Size: 251 bytes --]

_______________________________________________
ffmpeg-devel mailing list
ffmpeg-devel@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-devel

To unsubscribe, visit link above, or email
ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".