swscale: dither for planar yuv outputs

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

4 files changed, 77 insertions, 54 deletions

diff --git a/libswscale/swscale.c b/libswscale/swscale.c
index 6bf7fcfd9d..65bb7c01c1 100644
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@@ -282,6 +282,8 @@ DECLARE_ALIGNED(8, const uint8_t, dithers)[8][8][8]={
   { 112, 16,104,  8,118, 22,110, 14,},
 }};
 
+static const uint8_t flat64[8]={64,64,64,64,64,64,64,64};
+
 uint16_t dither_scale[15][16]={
 {    2,    3,    3,    5,    5,    5,    5,    5,    5,    5,    5,    5,    5,    5,    5,    5,},
 {    2,    3,    7,    7,   13,   13,   25,   25,   25,   25,   25,   25,   25,   25,   25,   25,},
@@ -417,12 +419,13 @@ static inline void yuv2yuvX16inC(const int16_t *lumFilter, const int16_t **lumSr
 static inline void yuv2yuvXinC(const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
                                const int16_t *chrFilter, const int16_t **chrUSrc,
                                const int16_t **chrVSrc, int chrFilterSize,
-                               const int16_t **alpSrc, uint8_t *dest, uint8_t *uDest, uint8_t *vDest, uint8_t *aDest, int dstW, int chrDstW)
+                               const int16_t **alpSrc, uint8_t *dest, uint8_t *uDest, uint8_t *vDest, uint8_t *aDest, int dstW, int chrDstW,
+                               const uint8_t *lumDither, const uint8_t *chrDither)
 {
     //FIXME Optimize (just quickly written not optimized..)
     int i;
     for (i=0; i<dstW; i++) {
-        int val=1<<18;
+        int val = lumDither[i&7] << 12;
         int j;
         for (j=0; j<lumFilterSize; j++)
             val += lumSrc[j][i] * lumFilter[j];
@@ -432,8 +435,8 @@ static inline void yuv2yuvXinC(const int16_t *lumFilter, const int16_t **lumSrc,
 
     if (uDest)
         for (i=0; i<chrDstW; i++) {
-            int u=1<<18;
-            int v=1<<18;
+            int u = chrDither[i&7] << 12;
+            int v = chrDither[(i+3)&7] << 12;
             int j;
             for (j=0; j<chrFilterSize; j++) {
                 u += chrUSrc[j][i] * chrFilter[j];
@@ -446,7 +449,7 @@ static inline void yuv2yuvXinC(const int16_t *lumFilter, const int16_t **lumSrc,
 
     if (CONFIG_SWSCALE_ALPHA && aDest)
         for (i=0; i<dstW; i++) {
-            int val=1<<18;
+            int val = lumDither[i&7] << 12;
             int j;
             for (j=0; j<lumFilterSize; j++)
                 val += alpSrc[j][i] * lumFilter[j];
@@ -459,12 +462,13 @@ static inline void yuv2yuvXinC(const int16_t *lumFilter, const int16_t **lumSrc,
 static inline void yuv2nv12XinC(const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
                                 const int16_t *chrFilter, const int16_t **chrUSrc,
                                 const int16_t **chrVSrc, int chrFilterSize,
-                                uint8_t *dest, uint8_t *uDest, int dstW, int chrDstW, int dstFormat)
+                                uint8_t *dest, uint8_t *uDest, int dstW, int chrDstW, int dstFormat,
+                                const uint8_t *lumDither, const uint8_t *chrDither)
 {
     //FIXME Optimize (just quickly written not optimized..)
     int i;
     for (i=0; i<dstW; i++) {
-        int val=1<<18;
+        int val = lumDither[i&7]<<12;
         int j;
         for (j=0; j<lumFilterSize; j++)
             val += lumSrc[j][i] * lumFilter[j];
@@ -477,8 +481,8 @@ static inline void yuv2nv12XinC(const int16_t *lumFilter, const int16_t **lumSrc
 
     if (dstFormat == PIX_FMT_NV12)
         for (i=0; i<chrDstW; i++) {
-            int u=1<<18;
-            int v=1<<18;
+            int u = chrDither[i&7]<<12;
+            int v = chrDither[(i+3)&7]<<12;
             int j;
             for (j=0; j<chrFilterSize; j++) {
                 u += chrUSrc[j][i] * chrFilter[j];
@@ -490,8 +494,8 @@ static inline void yuv2nv12XinC(const int16_t *lumFilter, const int16_t **lumSrc
         }
     else
         for (i=0; i<chrDstW; i++) {
-            int u=1<<18;
-            int v=1<<18;
+            int u = chrDither[i&7]<<12;
+            int v = chrDither[(i+3)&7]<<12;
             int j;
             for (j=0; j<chrFilterSize; j++) {
                 u += chrUSrc[j][i] * chrFilter[j];
diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index 8577448c38..87712be1b3 100644
--- a/libswscale/swscale_internal.h
+++ b/libswscale/swscale_internal.h
@@ -195,6 +195,8 @@ typedef struct SwsContext {
 #define ALP_MMX_FILTER_OFFSET "11*8+4*4*256*2+48"
 #define UV_OFF                "11*8+4*4*256*3+48"
 #define UV_OFFx2              "11*8+4*4*256*3+56"
+#define DITHER16              "11*8+4*4*256*3+64"
+#define DITHER32              "11*8+4*4*256*3+64+16"
 
     DECLARE_ALIGNED(8, uint64_t, redDither);
     DECLARE_ALIGNED(8, uint64_t, greenDither);
@@ -219,6 +221,8 @@ typedef struct SwsContext {
     int32_t  alpMmxFilter[4*MAX_FILTER_SIZE];
     DECLARE_ALIGNED(8, ptrdiff_t, uv_off); ///< offset (in pixels) between u and v planes
     DECLARE_ALIGNED(8, ptrdiff_t, uv_offx2); ///< offset (in bytes) between u and v planes
+    uint16_t dither16[8];
+    uint32_t dither32[8];
 
 #if HAVE_ALTIVEC
     vector signed short   CY;
@@ -255,13 +259,13 @@ typedef struct SwsContext {
                         const int16_t *chrFilter, const int16_t **chrUSrc,
                         const int16_t **chrVSrc, int chrFilterSize,
                         uint8_t *dest, uint8_t *uDest,
-                        int dstW, int chrDstW, int dstFormat);
+                        int dstW, int chrDstW, int dstFormat, const uint8_t *lumDither, const uint8_t *chrDither);
     void (*yuv2yuv1   )(struct SwsContext *c,
                         const int16_t *lumSrc, const int16_t *chrUSrc,
                         const int16_t *chrVSrc, const int16_t *alpSrc,
                         uint8_t *dest,
                         uint8_t *uDest, uint8_t *vDest, uint8_t *aDest,
-                        int dstW, int chrDstW);
+                        int dstW, int chrDstW, const uint8_t *lumDither, const uint8_t *chrDither);
     void (*yuv2yuvX   )(struct SwsContext *c,
                         const int16_t *lumFilter, const int16_t **lumSrc, int lumFilterSize,
                         const int16_t *chrFilter, const int16_t **chrUSrc,
@@ -269,7 +273,7 @@ typedef struct SwsContext {
                         const int16_t **alpSrc,
                         uint8_t *dest,
                         uint8_t *uDest, uint8_t *vDest, uint8_t *aDest,
-                        int dstW, int chrDstW);
+                        int dstW, int chrDstW, const uint8_t *lumDither, const uint8_t *chrDither);
     void (*yuv2packed1)(struct SwsContext *c,
                         const uint16_t *buf0,
                         const uint16_t *ubuf0, const uint16_t *ubuf1,
diff --git a/libswscale/swscale_template.c b/libswscale/swscale_template.c
index 6c85487e9c..58e05ac7b3 100644
--- a/libswscale/swscale_template.c
+++ b/libswscale/swscale_template.c
@@ -24,11 +24,11 @@ static inline void yuv2yuvX_c(SwsContext *c, const int16_t *lumFilter,
                               const int16_t **chrVSrc,
                               int chrFilterSize, const int16_t **alpSrc,
                               uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                              uint8_t *aDest, int dstW, int chrDstW)
+                              uint8_t *aDest, int dstW, int chrDstW, const uint8_t *lumDither, const uint8_t *chrDither)
 {
     yuv2yuvXinC(lumFilter, lumSrc, lumFilterSize,
                 chrFilter, chrUSrc, chrVSrc, chrFilterSize,
-                alpSrc, dest, uDest, vDest, aDest, dstW, chrDstW);
+                alpSrc, dest, uDest, vDest, aDest, dstW, chrDstW, lumDither, chrDither);
 }
 
 static inline void yuv2nv12X_c(SwsContext *c, const int16_t *lumFilter,
@@ -36,36 +36,37 @@ static inline void yuv2nv12X_c(SwsContext *c, const int16_t *lumFilter,
                                const int16_t *chrFilter, const int16_t **chrUSrc,
                                const int16_t **chrVSrc,
                                int chrFilterSize, uint8_t *dest, uint8_t *uDest,
-                               int dstW, int chrDstW, enum PixelFormat dstFormat)
+                               int dstW, int chrDstW, enum PixelFormat dstFormat, const uint8_t *dither, const uint8_t *chrDither)
 {
     yuv2nv12XinC(lumFilter, lumSrc, lumFilterSize,
                  chrFilter, chrUSrc, chrVSrc, chrFilterSize,
-                 dest, uDest, dstW, chrDstW, dstFormat);
+                 dest, uDest, dstW, chrDstW, dstFormat, dither, chrDither);
 }
 
 static inline void yuv2yuv1_c(SwsContext *c, const int16_t *lumSrc,
                               const int16_t *chrUSrc, const int16_t *chrVSrc,
                               const int16_t *alpSrc,
                               uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                              uint8_t *aDest, int dstW, int chrDstW)
+                              uint8_t *aDest, int dstW, int chrDstW, const uint8_t *lumDither, const uint8_t *chrDither)
 {
     int i;
+
     for (i=0; i<dstW; i++) {
-        int val= (lumSrc[i]+64)>>7;
+        int val= (lumSrc[i]+lumDither[i&7])>>7;
         dest[i]= av_clip_uint8(val);
     }
 
     if (uDest)
         for (i=0; i<chrDstW; i++) {
-            int u=(chrUSrc[i]+64)>>7;
-            int v=(chrVSrc[i]+64)>>7;
+            int u=(chrUSrc[i]+chrDither[i&7])>>7;
+            int v=(chrVSrc[i]+chrDither[(i+3)&7])>>7;
             uDest[i]= av_clip_uint8(u);
             vDest[i]= av_clip_uint8(v);
         }
 
     if (CONFIG_SWSCALE_ALPHA && aDest)
         for (i=0; i<dstW; i++) {
-            int val= (alpSrc[i]+64)>>7;
+            int val= (alpSrc[i]+lumDither[i&7])>>7;
             aDest[i]= av_clip_uint8(val);
         }
 }
@@ -609,6 +610,8 @@ static int swScale_c(SwsContext *c, const uint8_t* src[], int srcStride[],
         unsigned char *uDest=dst[1]+dstStride[1]*chrDstY;
         unsigned char *vDest=dst[2]+dstStride[2]*chrDstY;
         unsigned char *aDest=(CONFIG_SWSCALE_ALPHA && alpPixBuf) ? dst[3]+dstStride[3]*dstY : NULL;
+        const uint8_t *lumDither= isNBPS(c->srcFormat) || is16BPS(c->srcFormat) ? dithers[7][dstY   &7] : flat64;
+        const uint8_t *chrDither= isNBPS(c->srcFormat) || is16BPS(c->srcFormat) ? dithers[7][chrDstY&7] : flat64;
 
         const int firstLumSrcY= vLumFilterPos[dstY]; //First line needed as input
         const int firstLumSrcY2= vLumFilterPos[FFMIN(dstY | ((1<<c->chrDstVSubSample) - 1), dstH-1)];
@@ -699,7 +702,7 @@ static int swScale_c(SwsContext *c, const uint8_t* src[], int srcStride[],
                 c->yuv2nv12X(c,
                              vLumFilter+dstY*vLumFilterSize   , lumSrcPtr, vLumFilterSize,
                              vChrFilter+chrDstY*vChrFilterSize, chrUSrcPtr, chrVSrcPtr, vChrFilterSize,
-                             dest, uDest, dstW, chrDstW, dstFormat);
+                             dest, uDest, dstW, chrDstW, dstFormat, lumDither, chrDither);
             } else if (isPlanarYUV(dstFormat) || dstFormat==PIX_FMT_GRAY8) { //YV12 like
                 const int chrSkipMask= (1<<c->chrDstVSubSample)-1;
                 if ((dstY&chrSkipMask) || isGray(dstFormat)) uDest=vDest= NULL; //FIXME split functions in lumi / chromi
@@ -716,13 +719,13 @@ static int swScale_c(SwsContext *c, const uint8_t* src[], int srcStride[],
                     const int16_t *chrVBuf= chrVSrcPtr[0];
                     const int16_t *alpBuf= (CONFIG_SWSCALE_ALPHA && alpPixBuf) ? alpSrcPtr[0] : NULL;
                     c->yuv2yuv1(c, lumBuf, chrUBuf, chrVBuf, alpBuf, dest,
-                                uDest, vDest, aDest, dstW, chrDstW);
+                                uDest, vDest, aDest, dstW, chrDstW, lumDither, chrDither);
                 } else { //General YV12
                     c->yuv2yuvX(c,
                                 vLumFilter+dstY*vLumFilterSize   , lumSrcPtr, vLumFilterSize,
                                 vChrFilter+chrDstY*vChrFilterSize, chrUSrcPtr,
                                 chrVSrcPtr, vChrFilterSize,
-                                alpSrcPtr, dest, uDest, vDest, aDest, dstW, chrDstW);
+                                alpSrcPtr, dest, uDest, vDest, aDest, dstW, chrDstW, lumDither, chrDither);
                 }
             } else {
                 assert(lumSrcPtr  + vLumFilterSize - 1 < lumPixBuf  + vLumBufSize*2);
@@ -784,7 +787,7 @@ static int swScale_c(SwsContext *c, const uint8_t* src[], int srcStride[],
                 yuv2nv12XinC(
                              vLumFilter+dstY*vLumFilterSize   , lumSrcPtr, vLumFilterSize,
                              vChrFilter+chrDstY*vChrFilterSize, chrUSrcPtr, chrVSrcPtr, vChrFilterSize,
-                             dest, uDest, dstW, chrDstW, dstFormat);
+                             dest, uDest, dstW, chrDstW, dstFormat, lumDither, chrDither);
             } else if (isPlanarYUV(dstFormat) || dstFormat==PIX_FMT_GRAY8) { //YV12
                 const int chrSkipMask= (1<<c->chrDstVSubSample)-1;
                 if ((dstY&chrSkipMask) || isGray(dstFormat)) uDest=vDest= NULL; //FIXME split functions in lumi / chromi
@@ -798,7 +801,7 @@ static int swScale_c(SwsContext *c, const uint8_t* src[], int srcStride[],
                     yuv2yuvXinC(
                                 vLumFilter+dstY*vLumFilterSize   , lumSrcPtr, vLumFilterSize,
                                 vChrFilter+chrDstY*vChrFilterSize, chrUSrcPtr, chrVSrcPtr, vChrFilterSize,
-                                alpSrcPtr, dest, uDest, vDest, aDest, dstW, chrDstW);
+                                alpSrcPtr, dest, uDest, vDest, aDest, dstW, chrDstW, lumDither, chrDither);
                 }
             } else {
                 assert(lumSrcPtr + vLumFilterSize - 1 < lumPixBuf + vLumBufSize*2);
diff --git a/libswscale/x86/swscale_template.c b/libswscale/x86/swscale_template.c
index e2a530ae8d..d726c175f6 100644
--- a/libswscale/x86/swscale_template.c
+++ b/libswscale/x86/swscale_template.c
@@ -39,8 +39,8 @@
 
 #define YSCALEYUV2YV12X(offset, dest, end, pos) \
     __asm__ volatile(\
-        "movq             "VROUNDER_OFFSET"(%0), %%mm3      \n\t"\
-        "movq                             %%mm3, %%mm4      \n\t"\
+        "movq                  "DITHER16"+0(%0), %%mm3      \n\t"\
+        "movq                  "DITHER16"+8(%0), %%mm4      \n\t"\
         "lea                     " offset "(%0), %%"REG_d"  \n\t"\
         "mov                        (%%"REG_d"), %%"REG_S"  \n\t"\
         ".p2align                             4             \n\t" /* FIXME Unroll? */\
@@ -62,8 +62,8 @@
         MOVNTQ(%%mm3, (%1, %3))\
         "add                                 $8, %3         \n\t"\
         "cmp                                 %2, %3         \n\t"\
-        "movq             "VROUNDER_OFFSET"(%0), %%mm3      \n\t"\
-        "movq                             %%mm3, %%mm4      \n\t"\
+        "movq                  "DITHER16"+0(%0), %%mm3      \n\t"\
+        "movq                  "DITHER16"+8(%0), %%mm4      \n\t"\
         "lea                     " offset "(%0), %%"REG_d"  \n\t"\
         "mov                        (%%"REG_d"), %%"REG_S"  \n\t"\
         "jb                                  1b             \n\t"\
@@ -78,13 +78,18 @@ static inline void RENAME(yuv2yuvX)(SwsContext *c, const int16_t *lumFilter,
                                     const int16_t **chrVSrc,
                                     int chrFilterSize, const int16_t **alpSrc,
                                     uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                                    uint8_t *aDest, int dstW, int chrDstW)
+                                    uint8_t *aDest, int dstW, int chrDstW,
+                                    const uint8_t *lumDither, const uint8_t *chrDither)
 {
+    int i;
     if (uDest) {
         x86_reg uv_off = c->uv_off;
+        for(i=0; i<8; i++) c->dither16[i] = chrDither[i]>>4;
         YSCALEYUV2YV12X(CHR_MMX_FILTER_OFFSET, uDest, chrDstW, 0)
+        for(i=0; i<8; i++) c->dither16[i] = chrDither[(i+3)&7]>>4;
         YSCALEYUV2YV12X(CHR_MMX_FILTER_OFFSET, vDest - uv_off, chrDstW + uv_off, uv_off)
     }
+    for(i=0; i<8; i++) c->dither16[i] = lumDither[i]>>4;
     if (CONFIG_SWSCALE_ALPHA && aDest) {
         YSCALEYUV2YV12X(ALP_MMX_FILTER_OFFSET, aDest, dstW, 0)
     }
@@ -95,6 +100,10 @@ static inline void RENAME(yuv2yuvX)(SwsContext *c, const int16_t *lumFilter,
 #define YSCALEYUV2YV12X_ACCURATE(offset, dest, end, pos) \
     __asm__ volatile(\
         "lea                     " offset "(%0), %%"REG_d"  \n\t"\
+        "movq                  "DITHER32"+0(%0), %%mm4      \n\t"\
+        "movq                  "DITHER32"+8(%0), %%mm5      \n\t"\
+        "movq                 "DITHER32"+16(%0), %%mm6      \n\t"\
+        "movq                 "DITHER32"+24(%0), %%mm7      \n\t"\
         "pxor                             %%mm4, %%mm4      \n\t"\
         "pxor                             %%mm5, %%mm5      \n\t"\
         "pxor                             %%mm6, %%mm6      \n\t"\
@@ -126,26 +135,21 @@ static inline void RENAME(yuv2yuvX)(SwsContext *c, const int16_t *lumFilter,
         "paddd                            %%mm2, %%mm6      \n\t"\
         "paddd                            %%mm0, %%mm7      \n\t"\
         " jnz                                1b             \n\t"\
-        "psrad                              $16, %%mm4      \n\t"\
-        "psrad                              $16, %%mm5      \n\t"\
-        "psrad                              $16, %%mm6      \n\t"\
-        "psrad                              $16, %%mm7      \n\t"\
-        "movq             "VROUNDER_OFFSET"(%0), %%mm0      \n\t"\
+        "psrad                              $19, %%mm4      \n\t"\
+        "psrad                              $19, %%mm5      \n\t"\
+        "psrad                              $19, %%mm6      \n\t"\
+        "psrad                              $19, %%mm7      \n\t"\
         "packssdw                         %%mm5, %%mm4      \n\t"\
         "packssdw                         %%mm7, %%mm6      \n\t"\
-        "paddw                            %%mm0, %%mm4      \n\t"\
-        "paddw                            %%mm0, %%mm6      \n\t"\
-        "psraw                               $3, %%mm4      \n\t"\
-        "psraw                               $3, %%mm6      \n\t"\
         "packuswb                         %%mm6, %%mm4      \n\t"\
         MOVNTQ(%%mm4, (%1, %3))\
         "add                                 $8, %3         \n\t"\
         "cmp                                 %2, %3         \n\t"\
         "lea                     " offset "(%0), %%"REG_d"  \n\t"\
-        "pxor                             %%mm4, %%mm4      \n\t"\
-        "pxor                             %%mm5, %%mm5      \n\t"\
-        "pxor                             %%mm6, %%mm6      \n\t"\
-        "pxor                             %%mm7, %%mm7      \n\t"\
+        "movq                  "DITHER32"+0(%0), %%mm4      \n\t"\
+        "movq                  "DITHER32"+8(%0), %%mm5      \n\t"\
+        "movq                 "DITHER32"+16(%0), %%mm6      \n\t"\
+        "movq                 "DITHER32"+24(%0), %%mm7      \n\t"\
         "mov                        (%%"REG_d"), %%"REG_S"  \n\t"\
         "jb                                  1b             \n\t"\
         :: "r" (&c->redDither),\
@@ -159,13 +163,18 @@ static inline void RENAME(yuv2yuvX_ar)(SwsContext *c, const int16_t *lumFilter,
                                        const int16_t **chrVSrc,
                                        int chrFilterSize, const int16_t **alpSrc,
                                        uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                                       uint8_t *aDest, int dstW, int chrDstW)
+                                       uint8_t *aDest, int dstW, int chrDstW,
+                                       const uint8_t *lumDither, const uint8_t *chrDither)
 {
+    int i;
     if (uDest) {
         x86_reg uv_off = c->uv_off;
+        for(i=0; i<8; i++) c->dither32[i] = chrDither[i]<<12;
         YSCALEYUV2YV12X_ACCURATE(CHR_MMX_FILTER_OFFSET, uDest, chrDstW, 0)
+        for(i=0; i<8; i++) c->dither32[i] = chrDither[(i+3)&7]<<12;
         YSCALEYUV2YV12X_ACCURATE(CHR_MMX_FILTER_OFFSET, vDest - uv_off, chrDstW + uv_off, uv_off)
     }
+    for(i=0; i<8; i++) c->dither32[i] = lumDither[i]<<12;
     if (CONFIG_SWSCALE_ALPHA && aDest) {
         YSCALEYUV2YV12X_ACCURATE(ALP_MMX_FILTER_OFFSET, aDest, dstW, 0)
     }
@@ -190,7 +199,8 @@ static inline void RENAME(yuv2yuv1)(SwsContext *c, const int16_t *lumSrc,
                                     const int16_t *chrUSrc, const int16_t *chrVSrc,
                                     const int16_t *alpSrc,
                                     uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                                    uint8_t *aDest, int dstW, int chrDstW)
+                                    uint8_t *aDest, int dstW, int chrDstW,
+                                    const uint8_t *lumDither, const uint8_t *chrDither)
 {
     int p= 4;
     const int16_t *src[4]= { alpSrc + dstW, lumSrc + dstW, chrUSrc + chrDstW, chrVSrc + chrDstW };
@@ -211,14 +221,13 @@ static inline void RENAME(yuv2yuv1)(SwsContext *c, const int16_t *lumSrc,
 
 #define YSCALEYUV2YV121_ACCURATE \
     "mov %2, %%"REG_a"                    \n\t"\
-    "pcmpeqw %%mm7, %%mm7                 \n\t"\
-    "psrlw                 $15, %%mm7     \n\t"\
-    "psllw                  $6, %%mm7     \n\t"\
+    "movq               0(%3), %%mm6      \n\t"\
+    "movq               8(%3), %%mm7      \n\t"\
     ".p2align                4            \n\t" /* FIXME Unroll? */\
     "1:                                   \n\t"\
     "movq  (%0, %%"REG_a", 2), %%mm0      \n\t"\
     "movq 8(%0, %%"REG_a", 2), %%mm1      \n\t"\
-    "paddsw             %%mm7, %%mm0      \n\t"\
+    "paddsw             %%mm6, %%mm0      \n\t"\
     "paddsw             %%mm7, %%mm1      \n\t"\
     "psraw                 $7, %%mm0      \n\t"\
     "psraw                 $7, %%mm1      \n\t"\
@@ -231,7 +240,8 @@ static inline void RENAME(yuv2yuv1_ar)(SwsContext *c, const int16_t *lumSrc,
                                        const int16_t *chrUSrc, const int16_t *chrVSrc,
                                        const int16_t *alpSrc,
                                        uint8_t *dest, uint8_t *uDest, uint8_t *vDest,
-                                       uint8_t *aDest, int dstW, int chrDstW)
+                                       uint8_t *aDest, int dstW, int chrDstW,
+                                       const uint8_t *lumDither, const uint8_t *chrDither)
 {
     int p= 4;
     const int16_t *src[4]= { alpSrc + dstW, lumSrc + dstW, chrUSrc + chrDstW, chrVSrc + chrDstW };
@@ -240,10 +250,12 @@ static inline void RENAME(yuv2yuv1_ar)(SwsContext *c, const int16_t *lumSrc,
 
     while (p--) {
         if (dst[p]) {
+            int i;
+            for(i=0; i<8; i++) c->dither16[i] = i<2 ? lumDither[i] : chrDither[i];
             __asm__ volatile(
                 YSCALEYUV2YV121_ACCURATE
                 :: "r" (src[p]), "r" (dst[p] + counter[p]),
-                   "g" (-counter[p])
+                   "g" (-counter[p]), "r"(c->dither16)
                 : "%"REG_a
             );
         }