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| author | Clément Bœsch <u@pkh.me> | 2022-12-27 17:38:10 +0100 |
|---|---|---|
| committer | Clément Bœsch <u@pkh.me> | 2023-01-03 17:18:55 +0100 |
| commit | 3cafbdc083914d3a921fb241625ca8b6ccae1297 (patch) | |
| tree | eb371d2713df2a1f2d099bb4ff5b0e5aedf83e90 /libavfilter | |
| parent | 051926868c9d901d719c6a41ae7653f4190aae77 (diff) | |
| download | ffmpeg-3cafbdc083914d3a921fb241625ca8b6ccae1297.tar.gz | |
avfilter/palette: add lowbias32 hashing
Diffstat (limited to 'libavfilter')
| -rw-r--r-- | libavfilter/palette.c | 10 | ||||
| -rw-r--r-- | libavfilter/palette.h | 5 |
2 files changed, 15 insertions, 0 deletions
diff --git a/libavfilter/palette.c b/libavfilter/palette.c index e3a27fc51e..bba136408c 100644 --- a/libavfilter/palette.c +++ b/libavfilter/palette.c @@ -207,3 +207,13 @@ uint32_t ff_oklab_int_to_srgb_u8(struct Lab c) return r<<16 | g<<8 | b; } + +uint32_t ff_lowbias32(uint32_t x) +{ + x ^= x >> 16; + x *= 0x7feb352d; + x ^= x >> 15; + x *= 0x846ca68b; + x ^= x >> 16; + return x; +} diff --git a/libavfilter/palette.h b/libavfilter/palette.h index 6839bf6fc6..d3acc854ba 100644 --- a/libavfilter/palette.h +++ b/libavfilter/palette.h @@ -55,4 +55,9 @@ struct Lab ff_srgb_u8_to_oklab_int(uint32_t srgb); */ uint32_t ff_oklab_int_to_srgb_u8(struct Lab c); +/* + * lowbias32 hashing from https://nullprogram.com/blog/2018/07/31/ + */ +uint32_t ff_lowbias32(uint32_t x); + #endif /* AVFILTER_PALETTE_H */ |