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authorMichael Niedermayer <michaelni@gmx.at>2013-04-16 11:15:47 +0200
committerMichael Niedermayer <michaelni@gmx.at>2013-04-16 11:33:40 +0200
commitbcf643486f468d058cccb3ebc7bfbf8839ad7680 (patch)
tree9acc0841ae92887f59e38beec17507aa5d69370e /libswscale/utils.c
parent2fa11a94a312aa072d7d14204a09582950bebccb (diff)
downloadffmpeg-bcf643486f468d058cccb3ebc7bfbf8839ad7680.tar.gz
sws/fill_rgb2yuv_table: increase precission to 32bit
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libswscale/utils.c')
-rw-r--r--libswscale/utils.c30
1 files changed, 17 insertions, 13 deletions
diff --git a/libswscale/utils.c b/libswscale/utils.c
index 71e85e010f..0ea05dd902 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -801,7 +801,7 @@ static void getSubSampleFactors(int *h, int *v, enum AVPixelFormat format)
static void fill_rgb2yuv_table(SwsContext *c, const int table[4], int dstRange)
{
- int64_t W,V,Z;
+ int64_t W, V, Z, Cy, Cu, Cv;
int64_t vr = table[0];
int64_t ub = table[1];
int64_t ug = -table[2];
@@ -858,21 +858,25 @@ static void fill_rgb2yuv_table(SwsContext *c, const int table[4], int dstRange)
ug = ug * 224 / 255;
vg = vg * 224 / 255;
}
- W = ONE*ug/ub;
- V = ONE*vg/vr;
- Z = ONE-W-V;
+ W = ONE*ONE*ug/ub;
+ V = ONE*ONE*vg/vr;
+ Z = ONE*ONE-W-V;
- c->input_rgb2yuv_table[RY_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*V/(Z*cy);
- c->input_rgb2yuv_table[GY_IDX] = (1 << RGB2YUV_SHIFT)*ONE*ONE/(Z*cy);
- c->input_rgb2yuv_table[BY_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*W/(Z*cy);
+ Cy = cy*Z / ONE;
+ Cu = ub*Z / ONE;
+ Cv = vr*Z / ONE;
- c->input_rgb2yuv_table[RU_IDX] = (1 << RGB2YUV_SHIFT)*ONE*V/(Z*ub);
- c->input_rgb2yuv_table[GU_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*ONE/(Z*ub);
- c->input_rgb2yuv_table[BU_IDX] = (1 << RGB2YUV_SHIFT)*ONE*(Z+W)/(Z*ub);
+ c->input_rgb2yuv_table[RY_IDX] = -(1 << RGB2YUV_SHIFT)*V/Cy;
+ c->input_rgb2yuv_table[GY_IDX] = (1 << RGB2YUV_SHIFT)*ONE*ONE/Cy;
+ c->input_rgb2yuv_table[BY_IDX] = -(1 << RGB2YUV_SHIFT)*W/Cy;
- c->input_rgb2yuv_table[RV_IDX] = (1 << RGB2YUV_SHIFT)*ONE*(V+Z)/(Z*vr);
- c->input_rgb2yuv_table[GV_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*ONE/(Z*vr);
- c->input_rgb2yuv_table[BV_IDX] = (1 << RGB2YUV_SHIFT)*ONE*W/(Z*vr);
+ c->input_rgb2yuv_table[RU_IDX] = (1 << RGB2YUV_SHIFT)*V/Cu;
+ c->input_rgb2yuv_table[GU_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*ONE/Cu;
+ c->input_rgb2yuv_table[BU_IDX] = (1 << RGB2YUV_SHIFT)*(Z+W)/Cu;
+
+ c->input_rgb2yuv_table[RV_IDX] = (1 << RGB2YUV_SHIFT)*(V+Z)/Cv;
+ c->input_rgb2yuv_table[GV_IDX] = -(1 << RGB2YUV_SHIFT)*ONE*ONE/Cv;
+ c->input_rgb2yuv_table[BV_IDX] = (1 << RGB2YUV_SHIFT)*W/Cv;
if(/*!dstRange && */table == ff_yuv2rgb_coeffs[SWS_CS_DEFAULT]) {
c->input_rgb2yuv_table[BY_IDX] = ((int)(0.114 * 219 / 255 * (1 << RGB2YUV_SHIFT) + 0.5));