dany/libwebp
1
0
Fork 0
mirror of https://github.com/webmproject/libwebp.git synced 2025-07-13 06:24:27 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity

move some SSIM-accumulation function for dsp/

Browse Source 
This is in preparation for some SSE2 code.

And generally speaking, the whole SSIM code needs some
revamp: we're not averaging the SSIM value at each pixels
but just computing the overall SSIM value once, for the whole
plane. The former might be better than the latter.

Change-Id: I935784a917f84a18ef08dc5ec9a7b528abea46a5
This commit is contained in:
Pascal Massimino
2016-03-08 07:50:09 +01:00
parent f08e66245a
commit 423ecaf484
5 changed files with 149 additions and 54 deletions
Download Patch File Download Diff File Expand all files Collapse all files

29
src/dsp/dsp.h
View File

@ -215,6 +215,35 @@ extern VP8GetResidualCostFunc VP8GetResidualCost;
// must be called before anything using the above
void VP8EncDspCostInit(void);
//------------------------------------------------------------------------------
// SSIM utils
// struct for accumulating statistical moments
typedef struct {
double w; // sum(w_i) : sum of weights
double xm, ym; // sum(w_i * x_i), sum(w_i * y_i)
double xxm, xym, yym; // sum(w_i * x_i * x_i), etc.
} VP8DistoStats;
#define VP8_SSIM_KERNEL 3 // total size of the kernel: 2 * VP8_SSIM_KERNEL + 1
typedef void (*VP8SSIMAccumulateClippedFunc)(const uint8_t* src1, int stride1,
const uint8_t* src2, int stride2,
int xo, int yo, // center position
int W, int H, // plane dimension
VP8DistoStats* const stats);
// This version is called with the guarantee that you can load 8 bytes and
// 8 rows at offset src1 and src2
typedef void (*VP8SSIMAccumulateFunc)(const uint8_t* src1, int stride1,
const uint8_t* src2, int stride2,
VP8DistoStats* const stats);
VP8SSIMAccumulateFunc VP8SSIMAccumulate; // unclipped / unchecked
VP8SSIMAccumulateClippedFunc VP8SSIMAccumulateClipped; // with clipping
// must be called before using any of the above directly
void VP8SSIMDspInit(void);
//------------------------------------------------------------------------------
// Decoding

62
src/dsp/enc.c
View File

@ -702,6 +702,68 @@ static void Copy16x8(const uint8_t* src, uint8_t* dst) {
Copy(src, dst, 16, 8);
}
//------------------------------------------------------------------------------
static void SSIMAccumulateClipped(const uint8_t* src1, int stride1,
const uint8_t* src2, int stride2,
int xo, int yo, int W, int H,
VP8DistoStats* const stats) {
const int ymin = (yo - VP8_SSIM_KERNEL < 0) ? 0 : yo - VP8_SSIM_KERNEL;
const int ymax = (yo + VP8_SSIM_KERNEL > H - 1) ? H - 1
: yo + VP8_SSIM_KERNEL;
const int xmin = (xo - VP8_SSIM_KERNEL < 0) ? 0 : xo - VP8_SSIM_KERNEL;
const int xmax = (xo + VP8_SSIM_KERNEL > W - 1) ? W - 1
: xo + VP8_SSIM_KERNEL;
int x, y;
src1 += ymin * stride1;
src2 += ymin * stride2;
for (y = ymin; y <= ymax; ++y, src1 += stride1, src2 += stride2) {
for (x = xmin; x <= xmax; ++x) {
const int s1 = src1[x];
const int s2 = src2[x];
stats->w += 1;
stats->xm += s1;
stats->ym += s2;
stats->xxm += s1 * s1;
stats->xym += s1 * s2;
stats->yym += s2 * s2;
}
}
}
static void SSIMAccumulate(const uint8_t* src1, int stride1,
const uint8_t* src2, int stride2,
VP8DistoStats* const stats) {
int x, y;
for (y = 0; y <= 2 * VP8_SSIM_KERNEL; ++y, src1 += stride1, src2 += stride2) {
for (x = 0; x <= 2 * VP8_SSIM_KERNEL; ++x) {
const int s1 = src1[x];
const int s2 = src2[x];
stats->w += 1;
stats->xm += s1;
stats->ym += s2;
stats->xxm += s1 * s1;
stats->xym += s1 * s2;
stats->yym += s2 * s2;
}
}
}
VP8SSIMAccumulateFunc VP8SSIMAccumulate;
VP8SSIMAccumulateClippedFunc VP8SSIMAccumulateClipped;
static volatile VP8CPUInfo ssim_last_cpuinfo_used =
(VP8CPUInfo)&ssim_last_cpuinfo_used;
WEBP_TSAN_IGNORE_FUNCTION void VP8SSIMDspInit(void) {
if (ssim_last_cpuinfo_used == VP8GetCPUInfo) return;
VP8SSIMAccumulate = SSIMAccumulate;
VP8SSIMAccumulateClipped = SSIMAccumulateClipped;
ssim_last_cpuinfo_used = VP8GetCPUInfo;
}
//------------------------------------------------------------------------------
// Initialization