sRGB colors are gamma encoded, averaging them naively is incorrect. --- libavfilter/vf_palettegen.c | 18 ++++++++++-------- tests/ref/fate/filter-palettegen-1 | 2 +- tests/ref/fate/filter-palettegen-2 | 2 +- 3 files changed, 12 insertions(+), 10 deletions(-)
diff --git a/libavfilter/vf_palettegen.c b/libavfilter/vf_palettegen.c index d335ef91e6..00bc323d17 100644 --- a/libavfilter/vf_palettegen.c +++ b/libavfilter/vf_palettegen.c @@ -30,6 +30,7 @@ #include "libavutil/intreadwrite.h" #include "avfilter.h" #include "internal.h" +#include "palette.h" /* Reference a color and how much it's used */ struct color_ref { @@ -186,21 +187,22 @@ static int get_next_box_id_to_split(PaletteGenContext *s) static uint32_t get_avg_color(struct color_ref * const *refs, const struct range_box *box) { - int i; + int i, r, g, b; const int n = box->len; - uint64_t r = 0, g = 0, b = 0, div = 0; + uint64_t div = 0; + double rf = 0.0, gf = 0.0, bf = 0.0; for (i = 0; i < n; i++) { const struct color_ref *ref = refs[box->start + i]; - r += (ref->color >> 16 & 0xff) * ref->count; - g += (ref->color >> 8 & 0xff) * ref->count; - b += (ref->color & 0xff) * ref->count; + rf += ff_srgb_u8_to_linear_f32(ref->color >> 16 & 0xff) * ref->count; + gf += ff_srgb_u8_to_linear_f32(ref->color >> 8 & 0xff) * ref->count; + bf += ff_srgb_u8_to_linear_f32(ref->color & 0xff) * ref->count; div += ref->count; } - r = r / div; - g = g / div; - b = b / div; + r = ff_linear_f32_to_srgb_u8(rf / div); + g = ff_linear_f32_to_srgb_u8(gf / div); + b = ff_linear_f32_to_srgb_u8(bf / div); return 0xffU<<24 | r<<16 | g<<8 | b; } diff --git a/tests/ref/fate/filter-palettegen-1 b/tests/ref/fate/filter-palettegen-1 index bebfd24e19..df3b714ebb 100644 --- a/tests/ref/fate/filter-palettegen-1 +++ b/tests/ref/fate/filter-palettegen-1 @@ -3,4 +3,4 @@ #codec_id 0: rawvideo #dimensions 0: 16x16 #sar 0: 1/1 -0, 0, 0, 1, 1024, 0x3395ef5a +0, 0, 0, 1, 1024, 0x69ec37aa diff --git a/tests/ref/fate/filter-palettegen-2 b/tests/ref/fate/filter-palettegen-2 index 9abec0fe8e..08320a8359 100644 --- a/tests/ref/fate/filter-palettegen-2 +++ b/tests/ref/fate/filter-palettegen-2 @@ -3,4 +3,4 @@ #codec_id 0: rawvideo #dimensions 0: 16x16 #sar 0: 1/1 -0, 0, 0, 1, 1024, 0x23e072c8 +0, 0, 0, 1, 1024, 0x76078b2e -- 2.38.1 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".