[FFmpeg-devel] [PATCH v2 1/3] swscale: use 16-bit intermediate precision for RGB/XYZ conversion

[Michael Niedermayer]

On Mon, Dec 23, 2024 at 01:26:33PM +0100, Niklas Haas wrote:
> From: Niklas Haas <git at haasn.dev>
> 
> 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: ticket 4829
> Signed-off-by: Niklas Haas <git at haasn.dev>
> Sponsored-by: Sovereign Tech Fund
> ---
>  libswscale/swscale.c                     | 16 ++++++++--------
>  libswscale/swscale_internal.h            |  8 ++++----
>  libswscale/utils.c                       | 19 ++++++++++++-------
>  tests/ref/fate/filter-pixdesc-xyz12be    |  2 +-
>  tests/ref/fate/filter-pixdesc-xyz12le    |  2 +-
>  tests/ref/fate/filter-pixfmts-copy       |  4 ++--
>  tests/ref/fate/filter-pixfmts-crop       |  4 ++--
>  tests/ref/fate/filter-pixfmts-field      |  4 ++--
>  tests/ref/fate/filter-pixfmts-fieldorder |  4 ++--
>  tests/ref/fate/filter-pixfmts-hflip      |  4 ++--
>  tests/ref/fate/filter-pixfmts-il         |  4 ++--
>  tests/ref/fate/filter-pixfmts-null       |  4 ++--
>  tests/ref/fate/filter-pixfmts-scale      |  4 ++--
>  tests/ref/fate/filter-pixfmts-transpose  |  4 ++--
>  tests/ref/fate/filter-pixfmts-vflip      |  4 ++--
>  tests/ref/pixfmt/gbrp-xyz12le            |  2 +-
>  tests/ref/pixfmt/gbrp10-xyz12le          |  2 +-
>  tests/ref/pixfmt/gbrp12-xyz12le          |  2 +-
>  tests/ref/pixfmt/rgb24-xyz12le           |  2 +-
>  tests/ref/pixfmt/rgb48-xyz12le           |  2 +-
>  tests/ref/pixfmt/xyz12le                 |  2 +-
>  tests/ref/pixfmt/yuv444p-xyz12le         |  2 +-
>  tests/ref/pixfmt/yuv444p10-xyz12le       |  2 +-
>  tests/ref/pixfmt/yuv444p12-xyz12le       |  2 +-
>  24 files changed, 55 insertions(+), 50 deletions(-)

better quality ++
LGTM

thx

[...]
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Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

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