Commit 1ce724ee authored by Ronald S. Bultje's avatar Ronald S. Bultje

swscale: implement error dithering in planarCopyWrapper.

Based on a somewhat similar idea in FFmpeg's swscale.
parent 4e3e333a
......@@ -34,6 +34,48 @@
#include "libavutil/bswap.h"
#include "libavutil/pixdesc.h"
DECLARE_ALIGNED(8, const uint8_t, dither_8x8_1)[8][8] = {
{ 0, 1, 0, 1, 0, 1, 0, 1,},
{ 1, 0, 1, 0, 1, 0, 1, 0,},
{ 0, 1, 0, 1, 0, 1, 0, 1,},
{ 1, 0, 1, 0, 1, 0, 1, 0,},
{ 0, 1, 0, 1, 0, 1, 0, 1,},
{ 1, 0, 1, 0, 1, 0, 1, 0,},
{ 0, 1, 0, 1, 0, 1, 0, 1,},
{ 1, 0, 1, 0, 1, 0, 1, 0,},
};
DECLARE_ALIGNED(8, const uint8_t, dither_8x8_3)[8][8] = {
{ 1, 2, 1, 2, 1, 2, 1, 2,},
{ 3, 0, 3, 0, 3, 0, 3, 0,},
{ 1, 2, 1, 2, 1, 2, 1, 2,},
{ 3, 0, 3, 0, 3, 0, 3, 0,},
{ 1, 2, 1, 2, 1, 2, 1, 2,},
{ 3, 0, 3, 0, 3, 0, 3, 0,},
{ 1, 2, 1, 2, 1, 2, 1, 2,},
{ 3, 0, 3, 0, 3, 0, 3, 0,},
};
DECLARE_ALIGNED(8, const uint8_t, dither_8x8_64)[8][8] = {
{ 18, 34, 30, 46, 17, 33, 29, 45,},
{ 50, 2, 62, 14, 49, 1, 61, 13,},
{ 26, 42, 22, 38, 25, 41, 21, 37,},
{ 58, 10, 54, 6, 57, 9, 53, 5,},
{ 16, 32, 28, 44, 19, 35, 31, 47,},
{ 48, 0, 60, 12, 51, 3, 63, 15,},
{ 24, 40, 20, 36, 27, 43, 23, 39,},
{ 56, 8, 52, 4, 59, 11, 55, 7,},
};
extern const uint8_t dither_8x8_128[8][8];
DECLARE_ALIGNED(8, const uint8_t, dither_8x8_256)[8][8] = {
{ 72, 136, 120, 184, 68, 132, 116, 180,},
{ 200, 8, 248, 56, 196, 4, 244, 52,},
{ 104, 168, 88, 152, 100, 164, 84, 148,},
{ 232, 40, 216, 24, 228, 36, 212, 20,},
{ 64, 128, 102, 176, 76, 140, 124, 188,},
{ 192, 0, 240, 48, 204, 12, 252, 60,},
{ 96, 160, 80, 144, 108, 172, 92, 156,},
{ 224, 32, 208, 16, 236, 44, 220, 28,},
};
#define RGB2YUV_SHIFT 15
#define BY ( (int)(0.114*219/255*(1<<RGB2YUV_SHIFT)+0.5))
#define BV (-(int)(0.081*224/255*(1<<RGB2YUV_SHIFT)+0.5))
......@@ -412,6 +454,25 @@ static int packedCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[
return srcSliceH;
}
#define DITHER_COPY(dst, dstStride, wfunc, src, srcStride, rfunc, dithers, shift) \
for (i = 0; i < height; i++) { \
const uint8_t *dither = dithers[i & 7]; \
for (j = 0; j < length - 7; j += 8) { \
wfunc(&dst[j + 0], (rfunc(&src[j + 0]) + dither[0]) >> shift); \
wfunc(&dst[j + 1], (rfunc(&src[j + 1]) + dither[1]) >> shift); \
wfunc(&dst[j + 2], (rfunc(&src[j + 2]) + dither[2]) >> shift); \
wfunc(&dst[j + 3], (rfunc(&src[j + 3]) + dither[3]) >> shift); \
wfunc(&dst[j + 4], (rfunc(&src[j + 4]) + dither[4]) >> shift); \
wfunc(&dst[j + 5], (rfunc(&src[j + 5]) + dither[5]) >> shift); \
wfunc(&dst[j + 6], (rfunc(&src[j + 6]) + dither[6]) >> shift); \
wfunc(&dst[j + 7], (rfunc(&src[j + 7]) + dither[7]) >> shift); \
} \
for (; j < length; j++) \
wfunc(&dst[j], (rfunc(&src[j]) + dither[j & 7]) >> shift); \
dst += dstStride; \
src += srcStride; \
}
static int planarCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[], int srcSliceY,
int srcSliceH, uint8_t* dst[], int dstStride[])
{
......@@ -475,7 +536,9 @@ static int planarCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[
COPY9_OR_10TO9_OR_10(int srcpx = rfunc(&srcPtr2[j]); \
wfunc(&dstPtr2[j], (srcpx << 1) | (srcpx >> 9))); \
} else if (dst_depth < src_depth) { \
COPY9_OR_10TO9_OR_10(wfunc(&dstPtr2[j], rfunc(&srcPtr2[j]) >> 1)); \
DITHER_COPY(dstPtr2, dstStride[plane]/2, wfunc, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_1, 1); \
} else { \
COPY9_OR_10TO9_OR_10(wfunc(&dstPtr2[j], rfunc(&srcPtr2[j]))); \
}
......@@ -493,14 +556,16 @@ static int planarCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[
}
}
} else {
// FIXME Maybe dither instead.
#define W8(a, b) { *(a) = (b); }
#define COPY9_OR_10TO8(rfunc) \
for (i = 0; i < height; i++) { \
for (j = 0; j < length; j++) { \
dstPtr[j] = rfunc(&srcPtr2[j])>>(src_depth-8); \
} \
dstPtr += dstStride[plane]; \
srcPtr2 += srcStride[plane]/2; \
if (src_depth == 9) { \
DITHER_COPY(dstPtr, dstStride[plane], W8, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_1, 1); \
} else { \
DITHER_COPY(dstPtr, dstStride[plane], W8, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_3, 2); \
}
if (isBE(c->srcFormat)) {
COPY9_OR_10TO8(AV_RB16);
......@@ -515,12 +580,14 @@ static int planarCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[
if (is16BPS(c->srcFormat)) {
const uint16_t *srcPtr2 = (const uint16_t*)srcPtr;
#define COPY16TO9_OR_10(rfunc, wfunc) \
for (i = 0; i < height; i++) { \
for (j = 0; j < length; j++) { \
wfunc(&dstPtr2[j], rfunc(&srcPtr2[j])>>(16-dst_depth)); \
} \
dstPtr2 += dstStride[plane]/2; \
srcPtr2 += srcStride[plane]/2; \
if (dst_depth == 9) { \
DITHER_COPY(dstPtr2, dstStride[plane]/2, wfunc, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_128, 7); \
} else { \
DITHER_COPY(dstPtr2, dstStride[plane]/2, wfunc, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_64, 6); \
}
if (isBE(c->dstFormat)) {
if (isBE(c->srcFormat)) {
......@@ -552,11 +619,15 @@ static int planarCopyWrapper(SwsContext *c, const uint8_t* src[], int srcStride[
}
}
} else if(is16BPS(c->srcFormat) && !is16BPS(c->dstFormat)) {
if (!isBE(c->srcFormat)) srcPtr++;
for (i=0; i<height; i++) {
for (j=0; j<length; j++) dstPtr[j] = srcPtr[j<<1];
srcPtr+= srcStride[plane];
dstPtr+= dstStride[plane];
const uint16_t *srcPtr2 = (const uint16_t*)srcPtr;
#define COPY16TO8(rfunc) \
DITHER_COPY(dstPtr, dstStride[plane], W8, \
srcPtr2, srcStride[plane]/2, rfunc, \
dither_8x8_256, 8);
if (isBE(c->srcFormat)) {
COPY16TO8(AV_RB16);
} else {
COPY16TO8(AV_RL16);
}
} else if(!is16BPS(c->srcFormat) && is16BPS(c->dstFormat)) {
for (i=0; i<height; i++) {
......
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