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 */