Commit 6c565fad authored by Yaowu Xu's avatar Yaowu Xu

change to use fast ssim code for internal ssim calculations

The commit also removed the slow ssim calculation that uses a 7x7
kernel, and revised the comments to better describe how sample ssim
values are computed and averaged

Change-Id: I1d874073cddca00f3c997f4b9a9a3db0aa212276
parent aeca5990
......@@ -96,7 +96,8 @@ extern double vp8_calc_ssimg
YV12_BUFFER_CONFIG *dest,
double *ssim_y,
double *ssim_u,
double *ssim_v
double *ssim_v,
const vp8_variance_rtcd_vtable_t *rtcd
);
......@@ -4984,7 +4985,8 @@ int vp8_get_compressed_data(VP8_PTR ptr, unsigned int *frame_flags, unsigned lon
if (cpi->b_calculate_ssimg)
{
double y, u, v, frame_all;
frame_all = vp8_calc_ssimg(cpi->Source, cm->frame_to_show, &y, &u, &v);
frame_all = vp8_calc_ssimg(cpi->Source, cm->frame_to_show,
&y, &u, &v, IF_RTCD(&cpi->rtcd.variance));
cpi->total_ssimg_y += y;
cpi->total_ssimg_u += u;
cpi->total_ssimg_v += v;
......
......@@ -18,223 +18,6 @@
#else
#define IF_RTCD(x) NULL
#endif
// Google version of SSIM
// SSIM
#define KERNEL 3
#define KERNEL_SIZE (2 * KERNEL + 1)
typedef unsigned char uint8;
typedef unsigned int uint32;
static const int K[KERNEL_SIZE] =
{
1, 4, 11, 16, 11, 4, 1 // 16 * exp(-0.3 * i * i)
};
static const double ki_w = 1. / 2304.; // 1 / sum(i:0..6, j..6) K[i]*K[j]
double get_ssimg(const uint8 *org, const uint8 *rec,
int xo, int yo, int W, int H,
const int stride1, const int stride2
)
{
// TODO(skal): use summed tables
int y, x;
const int ymin = (yo - KERNEL < 0) ? 0 : yo - KERNEL;
const int ymax = (yo + KERNEL > H - 1) ? H - 1 : yo + KERNEL;
const int xmin = (xo - KERNEL < 0) ? 0 : xo - KERNEL;
const int xmax = (xo + KERNEL > W - 1) ? W - 1 : xo + KERNEL;
// worst case of accumulation is a weight of 48 = 16 + 2 * (11 + 4 + 1)
// with a diff of 255, squares. That would a max error of 0x8ee0900,
// which fits into 32 bits integers.
uint32 w = 0, xm = 0, ym = 0, xxm = 0, xym = 0, yym = 0;
org += ymin * stride1;
rec += ymin * stride2;
for (y = ymin; y <= ymax; ++y, org += stride1, rec += stride2)
{
const int Wy = K[KERNEL + y - yo];
for (x = xmin; x <= xmax; ++x)
{
const int Wxy = Wy * K[KERNEL + x - xo];
// TODO(skal): inlined assembly
w += Wxy;
xm += Wxy * org[x];
ym += Wxy * rec[x];
xxm += Wxy * org[x] * org[x];
xym += Wxy * org[x] * rec[x];
yym += Wxy * rec[x] * rec[x];
}
}
{
const double iw = 1. / w;
const double iwx = xm * iw;
const double iwy = ym * iw;
double sxx = xxm * iw - iwx * iwx;
double syy = yym * iw - iwy * iwy;
// small errors are possible, due to rounding. Clamp to zero.
if (sxx < 0.) sxx = 0.;
if (syy < 0.) syy = 0.;
{
const double sxsy = sqrt(sxx * syy);
const double sxy = xym * iw - iwx * iwy;
static const double C11 = (0.01 * 0.01) * (255 * 255);
static const double C22 = (0.03 * 0.03) * (255 * 255);
static const double C33 = (0.015 * 0.015) * (255 * 255);
const double l = (2. * iwx * iwy + C11) / (iwx * iwx + iwy * iwy + C11);
const double c = (2. * sxsy + C22) / (sxx + syy + C22);
const double s = (sxy + C33) / (sxsy + C33);
return l * c * s;
}
}
}
double get_ssimfull_kernelg(const uint8 *org, const uint8 *rec,
int xo, int yo, int W, int H,
const int stride1, const int stride2)
{
// TODO(skal): use summed tables
// worst case of accumulation is a weight of 48 = 16 + 2 * (11 + 4 + 1)
// with a diff of 255, squares. That would a max error of 0x8ee0900,
// which fits into 32 bits integers.
int y_, x_;
uint32 xm = 0, ym = 0, xxm = 0, xym = 0, yym = 0;
org += (yo - KERNEL) * stride1;
org += (xo - KERNEL);
rec += (yo - KERNEL) * stride2;
rec += (xo - KERNEL);
for (y_ = 0; y_ < KERNEL_SIZE; ++y_, org += stride1, rec += stride2)
{
const int Wy = K[y_];
for (x_ = 0; x_ < KERNEL_SIZE; ++x_)
{
const int Wxy = Wy * K[x_];
// TODO(skal): inlined assembly
const int org_x = org[x_];
const int rec_x = rec[x_];
xm += Wxy * org_x;
ym += Wxy * rec_x;
xxm += Wxy * org_x * org_x;
xym += Wxy * org_x * rec_x;
yym += Wxy * rec_x * rec_x;
}
}
{
const double iw = ki_w;
const double iwx = xm * iw;
const double iwy = ym * iw;
double sxx = xxm * iw - iwx * iwx;
double syy = yym * iw - iwy * iwy;
// small errors are possible, due to rounding. Clamp to zero.
if (sxx < 0.) sxx = 0.;
if (syy < 0.) syy = 0.;
{
const double sxsy = sqrt(sxx * syy);
const double sxy = xym * iw - iwx * iwy;
static const double C11 = (0.01 * 0.01) * (255 * 255);
static const double C22 = (0.03 * 0.03) * (255 * 255);
static const double C33 = (0.015 * 0.015) * (255 * 255);
const double l = (2. * iwx * iwy + C11) / (iwx * iwx + iwy * iwy + C11);
const double c = (2. * sxsy + C22) / (sxx + syy + C22);
const double s = (sxy + C33) / (sxsy + C33);
return l * c * s;
}
}
}
double calc_ssimg(const uint8 *org, const uint8 *rec,
const int image_width, const int image_height,
const int stride1, const int stride2
)
{
int j, i;
double SSIM = 0.;
for (j = 0; j < KERNEL; ++j)
{
for (i = 0; i < image_width; ++i)
{
SSIM += get_ssimg(org, rec, i, j, image_width, image_height, stride1, stride2);
}
}
for (j = KERNEL; j < image_height - KERNEL; ++j)
{
for (i = 0; i < KERNEL; ++i)
{
SSIM += get_ssimg(org, rec, i, j, image_width, image_height, stride1, stride2);
}
for (i = KERNEL; i < image_width - KERNEL; ++i)
{
SSIM += get_ssimfull_kernelg(org, rec, i, j,
image_width, image_height, stride1, stride2);
}
for (i = image_width - KERNEL; i < image_width; ++i)
{
SSIM += get_ssimg(org, rec, i, j, image_width, image_height, stride1, stride2);
}
}
for (j = image_height - KERNEL; j < image_height; ++j)
{
for (i = 0; i < image_width; ++i)
{
SSIM += get_ssimg(org, rec, i, j, image_width, image_height, stride1, stride2);
}
}
return SSIM;
}
double vp8_calc_ssimg
(
YV12_BUFFER_CONFIG *source,
YV12_BUFFER_CONFIG *dest,
double *ssim_y,
double *ssim_u,
double *ssim_v
)
{
double ssim_all = 0;
int ysize = source->y_width * source->y_height;
int uvsize = ysize / 4;
*ssim_y = calc_ssimg(source->y_buffer, dest->y_buffer,
source->y_width, source->y_height,
source->y_stride, dest->y_stride);
*ssim_u = calc_ssimg(source->u_buffer, dest->u_buffer,
source->uv_width, source->uv_height,
source->uv_stride, dest->uv_stride);
*ssim_v = calc_ssimg(source->v_buffer, dest->v_buffer,
source->uv_width, source->uv_height,
source->uv_stride, dest->uv_stride);
ssim_all = (*ssim_y + *ssim_u + *ssim_v) / (ysize + uvsize + uvsize);
*ssim_y /= ysize;
*ssim_u /= uvsize;
*ssim_v /= uvsize;
return ssim_all;
}
void ssim_parms_c
......@@ -369,10 +152,10 @@ long dssim(unsigned char *s,int sp, unsigned char *r,int rp,
ssim3=0;
return (long)( ssim3 );
}
// TODO: (jbb) this 8x8 window might be too big + we may want to pick pixels
// such that the window regions overlap block boundaries to penalize blocking
// artifacts.
// We are using a 8x8 moving window with starting location of each 8x8 window
// on the 4x4 pixel grid. Such arrangement allows the windows to overlap
// block boundaries to penalize blocking artifacts.
double vp8_ssim2
(
unsigned char *img1,
......@@ -388,7 +171,7 @@ double vp8_ssim2
int samples =0;
double ssim_total=0;
// we can sample points as frequently as we like start with 1 per 4x4
// sample point start with each 4x4 location
for(i=0; i < height-8; i+=4, img1 += stride_img1*4, img2 += stride_img2*4)
{
for(j=0; j < width-8; j+=4 )
......@@ -400,7 +183,6 @@ double vp8_ssim2
}
ssim_total /= samples;
return ssim_total;
}
double vp8_calc_ssim
(
......@@ -431,4 +213,36 @@ double vp8_calc_ssim
*weight = 1;
return ssimv;
}
double vp8_calc_ssimg
(
YV12_BUFFER_CONFIG *source,
YV12_BUFFER_CONFIG *dest,
double *ssim_y,
double *ssim_u,
double *ssim_v,
const vp8_variance_rtcd_vtable_t *rtcd
)
{
double ssim_all = 0;
double a, b, c;
a = vp8_ssim2(source->y_buffer, dest->y_buffer,
source->y_stride, dest->y_stride, source->y_width,
source->y_height, rtcd);
b = vp8_ssim2(source->u_buffer, dest->u_buffer,
source->uv_stride, dest->uv_stride, source->uv_width,
source->uv_height, rtcd);
c = vp8_ssim2(source->v_buffer, dest->v_buffer,
source->uv_stride, dest->uv_stride, source->uv_width,
source->uv_height, rtcd);
*ssim_y = a;
*ssim_u = b;
*ssim_v = c;
ssim_all = (a * 4 + b + c) /6;
return ssim_all;
}
\ No newline at end of file
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