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/*
* Copyright (c) 2016, Alliance for Open Media. All rights reserved.
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*
* This code was originally written by: Nathan E. Egge, at the Daala
* project.
*/
#include <assert.h>
#include <math.h>
#include <stdlib.h>
#include <string.h>
#include "config/aom_config.h"
#include "config/aom_dsp_rtcd.h"
#include "aom_dsp/ssim.h"
typedef struct fs_level fs_level;
typedef struct fs_ctx fs_ctx;
#define SSIM_C1 (255 * 255 * 0.01 * 0.01)
#define SSIM_C2 (255 * 255 * 0.03 * 0.03)
#define SSIM_C1_10 (1023 * 1023 * 0.01 * 0.01)
#define SSIM_C1_12 (4095 * 4095 * 0.01 * 0.01)
#define SSIM_C2_10 (1023 * 1023 * 0.03 * 0.03)
#define SSIM_C2_12 (4095 * 4095 * 0.03 * 0.03)
#define MAX_SSIM_DB 100.0
#define FS_MINI(_a, _b) ((_a) < (_b) ? (_a) : (_b))
#define FS_MAXI(_a, _b) ((_a) > (_b) ? (_a) : (_b))
struct fs_level {
uint32_t *im1;
uint32_t *im2;
double *ssim;
int w;
int h;
};
struct fs_ctx {
fs_level *level;
int nlevels;
unsigned *col_buf;
};
static int fs_ctx_init(fs_ctx *_ctx, int _w, int _h, int _nlevels) {
unsigned char *data;
size_t data_size;
int lw;
int lh;
int l;
lw = (_w + 1) >> 1;
lh = (_h + 1) >> 1;
data_size =
_nlevels * sizeof(fs_level) + 2 * (lw + 8) * 8 * sizeof(*_ctx->col_buf);
for (l = 0; l < _nlevels; l++) {
size_t im_size;
size_t level_size;
im_size = lw * (size_t)lh;
level_size = 2 * im_size * sizeof(*_ctx->level[l].im1);
level_size += sizeof(*_ctx->level[l].ssim) - 1;
level_size /= sizeof(*_ctx->level[l].ssim);
level_size += im_size;
level_size *= sizeof(*_ctx->level[l].ssim);
data_size += level_size;
lw = (lw + 1) >> 1;
lh = (lh + 1) >> 1;
}
data = (unsigned char *)malloc(data_size);
if (!data) return -1;
_ctx->level = (fs_level *)data;
_ctx->nlevels = _nlevels;
data += _nlevels * sizeof(*_ctx->level);
lw = (_w + 1) >> 1;
lh = (_h + 1) >> 1;
for (l = 0; l < _nlevels; l++) {
size_t im_size;
size_t level_size;
_ctx->level[l].w = lw;
_ctx->level[l].h = lh;
im_size = lw * (size_t)lh;
level_size = 2 * im_size * sizeof(*_ctx->level[l].im1);
level_size += sizeof(*_ctx->level[l].ssim) - 1;
level_size /= sizeof(*_ctx->level[l].ssim);
level_size *= sizeof(*_ctx->level[l].ssim);
_ctx->level[l].im1 = (uint32_t *)data;
_ctx->level[l].im2 = _ctx->level[l].im1 + im_size;
data += level_size;
_ctx->level[l].ssim = (double *)data;
data += im_size * sizeof(*_ctx->level[l].ssim);
lw = (lw + 1) >> 1;
lh = (lh + 1) >> 1;
}
_ctx->col_buf = (unsigned *)data;
return 0;
}
static void fs_ctx_clear(fs_ctx *_ctx) { free(_ctx->level); }
static void fs_downsample_level(fs_ctx *_ctx, int _l) {
const uint32_t *src1;
const uint32_t *src2;
uint32_t *dst1;
uint32_t *dst2;
int w2;
int h2;
int w;
int h;
int i;
int j;
w = _ctx->level[_l].w;
h = _ctx->level[_l].h;
dst1 = _ctx->level[_l].im1;
dst2 = _ctx->level[_l].im2;
w2 = _ctx->level[_l - 1].w;
h2 = _ctx->level[_l - 1].h;
src1 = _ctx->level[_l - 1].im1;
src2 = _ctx->level[_l - 1].im2;
for (j = 0; j < h; j++) {
int j0offs;
int j1offs;
j0offs = 2 * j * w2;
j1offs = FS_MINI(2 * j + 1, h2) * w2;
for (i = 0; i < w; i++) {
int i0;
int i1;
i0 = 2 * i;
i1 = FS_MINI(i0 + 1, w2);
dst1[j * w + i] = src1[j0offs + i0] + src1[j0offs + i1] +
src1[j1offs + i0] + src1[j1offs + i1];
dst2[j * w + i] = src2[j0offs + i0] + src2[j0offs + i1] +
src2[j1offs + i0] + src2[j1offs + i1];
}
}
}
static void fs_downsample_level0(fs_ctx *_ctx, const uint8_t *_src1,
int _s1ystride, const uint8_t *_src2,
int _s2ystride, int _w, int _h, uint32_t shift,
int buf_is_hbd) {
uint32_t *dst1;
uint32_t *dst2;
int w;
int h;
int i;
int j;
w = _ctx->level[0].w;
h = _ctx->level[0].h;
dst1 = _ctx->level[0].im1;
dst2 = _ctx->level[0].im2;
for (j = 0; j < h; j++) {
int j0;
int j1;
j0 = 2 * j;
j1 = FS_MINI(j0 + 1, _h);
for (i = 0; i < w; i++) {
int i0;
int i1;
i0 = 2 * i;
i1 = FS_MINI(i0 + 1, _w);
if (!buf_is_hbd) {
dst1[j * w + i] =
_src1[j0 * _s1ystride + i0] + _src1[j0 * _s1ystride + i1] +
_src1[j1 * _s1ystride + i0] + _src1[j1 * _s1ystride + i1];
dst2[j * w + i] =
_src2[j0 * _s2ystride + i0] + _src2[j0 * _s2ystride + i1] +
_src2[j1 * _s2ystride + i0] + _src2[j1 * _s2ystride + i1];
} else {
uint16_t *src1s = CONVERT_TO_SHORTPTR(_src1);
uint16_t *src2s = CONVERT_TO_SHORTPTR(_src2);
dst1[j * w + i] = (src1s[j0 * _s1ystride + i0] >> shift) +
(src1s[j0 * _s1ystride + i1] >> shift) +
(src1s[j1 * _s1ystride + i0] >> shift) +
(src1s[j1 * _s1ystride + i1] >> shift);
dst2[j * w + i] = (src2s[j0 * _s2ystride + i0] >> shift) +
(src2s[j0 * _s2ystride + i1] >> shift) +
(src2s[j1 * _s2ystride + i0] >> shift) +
(src2s[j1 * _s2ystride + i1] >> shift);
}
}
}
}
static void fs_apply_luminance(fs_ctx *_ctx, int _l, int bit_depth) {
unsigned *col_sums_x;
unsigned *col_sums_y;
uint32_t *im1;
uint32_t *im2;
double *ssim;
double c1;
int w;
int h;
int j0offs;
int j1offs;
int i;
int j;
double ssim_c1 = SSIM_C1;
if (bit_depth == 10) ssim_c1 = SSIM_C1_10;
if (bit_depth == 12) ssim_c1 = SSIM_C1_12;
w = _ctx->level[_l].w;
h = _ctx->level[_l].h;
col_sums_x = _ctx->col_buf;
col_sums_y = col_sums_x + w;
im1 = _ctx->level[_l].im1;
im2 = _ctx->level[_l].im2;
for (i = 0; i < w; i++) col_sums_x[i] = 5 * im1[i];
for (i = 0; i < w; i++) col_sums_y[i] = 5 * im2[i];
for (j = 1; j < 4; j++) {
j1offs = FS_MINI(j, h - 1) * w;
for (i = 0; i < w; i++) col_sums_x[i] += im1[j1offs + i];
for (i = 0; i < w; i++) col_sums_y[i] += im2[j1offs + i];
}
ssim = _ctx->level[_l].ssim;
c1 = (double)(ssim_c1 * 4096 * (1 << 4 * _l));
for (j = 0; j < h; j++) {
unsigned mux;
unsigned muy;
int i0;
int i1;
mux = 5 * col_sums_x[0];
muy = 5 * col_sums_y[0];
for (i = 1; i < 4; i++) {
i1 = FS_MINI(i, w - 1);
mux += col_sums_x[i1];
muy += col_sums_y[i1];
}
for (i = 0; i < w; i++) {
ssim[j * w + i] *= (2 * mux * (double)muy + c1) /
(mux * (double)mux + muy * (double)muy + c1);
if (i + 1 < w) {
i0 = FS_MAXI(0, i - 4);
i1 = FS_MINI(i + 4, w - 1);
mux += col_sums_x[i1] - col_sums_x[i0];
muy += col_sums_x[i1] - col_sums_x[i0];
}
}
if (j + 1 < h) {
j0offs = FS_MAXI(0, j - 4) * w;
for (i = 0; i < w; i++) col_sums_x[i] -= im1[j0offs + i];
for (i = 0; i < w; i++) col_sums_y[i] -= im2[j0offs + i];
j1offs = FS_MINI(j + 4, h - 1) * w;
for (i = 0; i < w; i++) col_sums_x[i] += im1[j1offs + i];
for (i = 0; i < w; i++) col_sums_y[i] += im2[j1offs + i];
}
}
}
#define FS_COL_SET(_col, _joffs, _ioffs) \
do { \
unsigned gx; \
unsigned gy; \
gx = gx_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
gy = gy_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
col_sums_gx2[(_col)] = gx * (double)gx; \
col_sums_gy2[(_col)] = gy * (double)gy; \
col_sums_gxgy[(_col)] = gx * (double)gy; \
} while (0)
#define FS_COL_ADD(_col, _joffs, _ioffs) \
do { \
unsigned gx; \
unsigned gy; \
gx = gx_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
gy = gy_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
col_sums_gx2[(_col)] += gx * (double)gx; \
col_sums_gy2[(_col)] += gy * (double)gy; \
col_sums_gxgy[(_col)] += gx * (double)gy; \
} while (0)
#define FS_COL_SUB(_col, _joffs, _ioffs) \
do { \
unsigned gx; \
unsigned gy; \
gx = gx_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
gy = gy_buf[((j + (_joffs)) & 7) * stride + i + (_ioffs)]; \
col_sums_gx2[(_col)] -= gx * (double)gx; \
col_sums_gy2[(_col)] -= gy * (double)gy; \
col_sums_gxgy[(_col)] -= gx * (double)gy; \
} while (0)
#define FS_COL_COPY(_col1, _col2) \
do { \
col_sums_gx2[(_col1)] = col_sums_gx2[(_col2)]; \
col_sums_gy2[(_col1)] = col_sums_gy2[(_col2)]; \
col_sums_gxgy[(_col1)] = col_sums_gxgy[(_col2)]; \
} while (0)
#define FS_COL_HALVE(_col1, _col2) \
do { \
col_sums_gx2[(_col1)] = col_sums_gx2[(_col2)] * 0.5; \
col_sums_gy2[(_col1)] = col_sums_gy2[(_col2)] * 0.5; \
col_sums_gxgy[(_col1)] = col_sums_gxgy[(_col2)] * 0.5; \
} while (0)
#define FS_COL_DOUBLE(_col1, _col2) \
do { \
col_sums_gx2[(_col1)] = col_sums_gx2[(_col2)] * 2; \
col_sums_gy2[(_col1)] = col_sums_gy2[(_col2)] * 2; \
col_sums_gxgy[(_col1)] = col_sums_gxgy[(_col2)] * 2; \
} while (0)
static void fs_calc_structure(fs_ctx *_ctx, int _l, int bit_depth) {
uint32_t *im1;
uint32_t *im2;
unsigned *gx_buf;
unsigned *gy_buf;
double *ssim;
double col_sums_gx2[8];
double col_sums_gy2[8];
double col_sums_gxgy[8];
double c2;
int stride;
int w;
int h;
int i;
int j;
double ssim_c2 = SSIM_C2;
if (bit_depth == 10) ssim_c2 = SSIM_C2_10;
if (bit_depth == 12) ssim_c2 = SSIM_C2_12;
w = _ctx->level[_l].w;
h = _ctx->level[_l].h;
im1 = _ctx->level[_l].im1;
im2 = _ctx->level[_l].im2;
ssim = _ctx->level[_l].ssim;
gx_buf = _ctx->col_buf;
stride = w + 8;
gy_buf = gx_buf + 8 * stride;
memset(gx_buf, 0, 2 * 8 * stride * sizeof(*gx_buf));
c2 = ssim_c2 * (1 << 4 * _l) * 16 * 104;
for (j = 0; j < h + 4; j++) {
if (j < h - 1) {
for (i = 0; i < w - 1; i++) {
unsigned g1;
unsigned g2;
unsigned gx;
unsigned gy;
g1 = abs((int)im1[(j + 1) * w + i + 1] - (int)im1[j * w + i]);
g2 = abs((int)im1[(j + 1) * w + i] - (int)im1[j * w + i + 1]);
gx = 4 * FS_MAXI(g1, g2) + FS_MINI(g1, g2);
g1 = abs((int)im2[(j + 1) * w + i + 1] - (int)im2[j * w + i]);
g2 = abs((int)im2[(j + 1) * w + i] - (int)im2[j * w + i + 1]);
gy = 4 * FS_MAXI(g1, g2) + FS_MINI(g1, g2);
gx_buf[(j & 7) * stride + i + 4] = gx;
gy_buf[(j & 7) * stride + i + 4] = gy;
}
} else {
memset(gx_buf + (j & 7) * stride, 0, stride * sizeof(*gx_buf));
memset(gy_buf + (j & 7) * stride, 0, stride * sizeof(*gy_buf));
}
if (j >= 4) {
int k;
col_sums_gx2[3] = col_sums_gx2[2] = col_sums_gx2[1] = col_sums_gx2[0] = 0;
col_sums_gy2[3] = col_sums_gy2[2] = col_sums_gy2[1] = col_sums_gy2[0] = 0;
col_sums_gxgy[3] = col_sums_gxgy[2] = col_sums_gxgy[1] =
col_sums_gxgy[0] = 0;
for (i = 4; i < 8; i++) {
FS_COL_SET(i, -1, 0);
FS_COL_ADD(i, 0, 0);
for (k = 1; k < 8 - i; k++) {
FS_COL_DOUBLE(i, i);
FS_COL_ADD(i, -k - 1, 0);
FS_COL_ADD(i, k, 0);
}
}
for (i = 0; i < w; i++) {
double mugx2;
double mugy2;
double mugxgy;
mugx2 = col_sums_gx2[0];
for (k = 1; k < 8; k++) mugx2 += col_sums_gx2[k];
mugy2 = col_sums_gy2[0];
for (k = 1; k < 8; k++) mugy2 += col_sums_gy2[k];
mugxgy = col_sums_gxgy[0];
for (k = 1; k < 8; k++) mugxgy += col_sums_gxgy[k];
ssim[(j - 4) * w + i] = (2 * mugxgy + c2) / (mugx2 + mugy2 + c2);
if (i + 1 < w) {
FS_COL_SET(0, -1, 1);
FS_COL_ADD(0, 0, 1);
FS_COL_SUB(2, -3, 2);
FS_COL_SUB(2, 2, 2);
FS_COL_HALVE(1, 2);
FS_COL_SUB(3, -4, 3);
FS_COL_SUB(3, 3, 3);
FS_COL_HALVE(2, 3);
FS_COL_COPY(3, 4);
FS_COL_DOUBLE(4, 5);
FS_COL_ADD(4, -4, 5);
FS_COL_ADD(4, 3, 5);
FS_COL_DOUBLE(5, 6);
FS_COL_ADD(5, -3, 6);
FS_COL_ADD(5, 2, 6);
FS_COL_DOUBLE(6, 7);
FS_COL_ADD(6, -2, 7);
FS_COL_ADD(6, 1, 7);
FS_COL_SET(7, -1, 8);
FS_COL_ADD(7, 0, 8);
}
}
}
}
}
#define FS_NLEVELS (4)
/*These weights were derived from the default weights found in Wang's original
Matlab implementation: {0.0448, 0.2856, 0.2363, 0.1333}.
We drop the finest scale and renormalize the rest to sum to 1.*/
static const double FS_WEIGHTS[FS_NLEVELS] = {
0.2989654541015625, 0.3141326904296875, 0.2473602294921875, 0.1395416259765625
};
static double fs_average(fs_ctx *_ctx, int _l) {
double *ssim;
double ret;
int w;
int h;
int i;
int j;
w = _ctx->level[_l].w;
h = _ctx->level[_l].h;
ssim = _ctx->level[_l].ssim;
ret = 0;
for (j = 0; j < h; j++)
for (i = 0; i < w; i++) ret += ssim[j * w + i];
return pow(ret / (w * h), FS_WEIGHTS[_l]);
}
static double convert_ssim_db(double _ssim, double _weight) {
assert(_weight >= _ssim);
if ((_weight - _ssim) < 1e-10) return MAX_SSIM_DB;
return 10 * (log10(_weight) - log10(_weight - _ssim));
}
static double calc_ssim(const uint8_t *_src, int _systride, const uint8_t *_dst,
int _dystride, int _w, int _h, uint32_t _bd,
uint32_t _shift, int buf_is_hbd) {
fs_ctx ctx;
double ret;
int l;
ret = 1;
if (fs_ctx_init(&ctx, _w, _h, FS_NLEVELS)) return 99.0;
fs_downsample_level0(&ctx, _src, _systride, _dst, _dystride, _w, _h, _shift,
buf_is_hbd);
for (l = 0; l < FS_NLEVELS - 1; l++) {
fs_calc_structure(&ctx, l, _bd);
ret *= fs_average(&ctx, l);
fs_downsample_level(&ctx, l + 1);
}
fs_calc_structure(&ctx, l, _bd);
fs_apply_luminance(&ctx, l, _bd);
ret *= fs_average(&ctx, l);
fs_ctx_clear(&ctx);
return ret;
}
double aom_calc_fastssim(const YV12_BUFFER_CONFIG *source,
const YV12_BUFFER_CONFIG *dest, double *ssim_y,
double *ssim_u, double *ssim_v, uint32_t bd,
uint32_t in_bd) {
double ssimv;
uint32_t bd_shift = 0;
assert(bd >= in_bd);
assert(source->flags == dest->flags);
int buf_is_hbd = source->flags & YV12_FLAG_HIGHBITDEPTH;
bd_shift = bd - in_bd;
*ssim_y = calc_ssim(source->y_buffer, source->y_stride, dest->y_buffer,
dest->y_stride, source->y_crop_width,
source->y_crop_height, in_bd, bd_shift, buf_is_hbd);
*ssim_u = calc_ssim(source->u_buffer, source->uv_stride, dest->u_buffer,
dest->uv_stride, source->uv_crop_width,
source->uv_crop_height, in_bd, bd_shift, buf_is_hbd);
*ssim_v = calc_ssim(source->v_buffer, source->uv_stride, dest->v_buffer,
dest->uv_stride, source->uv_crop_width,
source->uv_crop_height, in_bd, bd_shift, buf_is_hbd);
ssimv = (*ssim_y) * .8 + .1 * ((*ssim_u) + (*ssim_v));
return convert_ssim_db(ssimv, 1.0);
}