diff options
| author | Wim Taymans <wtaymans@redhat.com> | 2014-10-06 15:17:42 +0200 |
|---|---|---|
| committer | Wim Taymans <wtaymans@redhat.com> | 2014-10-08 11:36:15 +0200 |
| commit | e115e5059bc75c7100f15fbee38db4553f5bf314 (patch) | |
| tree | 0b9af66dac2f72ac263307a777e2587992195294 | |
| parent | 0b4abc267eb6c3fe1b8810ed03346d962bcc680e (diff) | |
video-chroma: improve 4x downsampling coefficients
| -rw-r--r-- | gst-libs/gst/video/video-chroma.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/gst-libs/gst/video/video-chroma.c b/gst-libs/gst/video/video-chroma.c index 15cf61c15..1fdf3e562 100644 --- a/gst-libs/gst/video/video-chroma.c +++ b/gst-libs/gst/video/video-chroma.c @@ -105,7 +105,7 @@ struct _GstVideoChromaResample #define PB3(i) (l3[3 + 4 * (i)]) #define FILT_1_1(a,b) ((a) + (b) + 1) >> 1 -#define FILT_1_1_1_1(a,b,c,d) ((a) + (b) + (c) + (d) + 2) >> 2 +#define FILT_1_3_3_1(a,b,c,d) ((a) + 3*(b) + 3*(c) + (d) + 4) >> 3 #define FILT_3_1(a,b) (3*(a) + (b) + 2) >> 2 #define FILT_1_3(a,b) ((a) + 3*(b) + 2) >> 2 @@ -448,7 +448,7 @@ video_chroma_up_vi4_##type (GstVideoChromaResample *resample, \ /* 4x horizontal downsampling without cositing * - * +------ (a + b + c + d + 2) >> 2 + * +------ (a + 3*b + 3*c + d + 4) >> 3 * | * v * ---O-------O--- @@ -467,8 +467,8 @@ video_chroma_down_h4_##type (GstVideoChromaResample *resample, \ type tr0 = PR(i), tr1 = PR(i+1), tr2 = PR(i+2), tr3 = PR(i+3); \ type tb0 = PB(i), tb1 = PB(i+1), tb2 = PB(i+2), tb3 = PB(i+3); \ \ - PR(i) = FILT_1_1_1_1 (tr0, tr1, tr2, tr3); \ - PB(i) = FILT_1_1_1_1 (tb0, tb1, tb2, tb3); \ + PR(i) = FILT_1_3_3_1 (tr0, tr1, tr2, tr3); \ + PB(i) = FILT_1_3_3_1 (tb0, tb1, tb2, tb3); \ } \ } @@ -476,7 +476,7 @@ video_chroma_down_h4_##type (GstVideoChromaResample *resample, \ * * a x--x--x- * b x--x--x- - * O O O <---- (a + b + c + d + 2) >> 2 + * O O O <---- (a + 3*b + 3*c + d + 4) >> 4 * c x--x--x- * d x--x--x- * e x--x--x- @@ -511,8 +511,8 @@ video_chroma_down_v4_##type (GstVideoChromaResample *resample, \ type tb0 = PB0(i), tb1 = PB1(i); \ type tb2 = PB2(i), tb3 = PB3(i); \ \ - PR0(i) = FILT_1_1_1_1 (tr0, tr1, tr2, tr3); \ - PB0(i) = FILT_1_1_1_1 (tb0, tb1, tb2, tb3); \ + PR0(i) = FILT_1_3_3_1 (tr0, tr1, tr2, tr3); \ + PB0(i) = FILT_1_3_3_1 (tb0, tb1, tb2, tb3); \ } \ } /* 4x vertical downsampling interlaced without cositing |