libvpx: Add VP9 decoder.

source/libvpx/vp9/encoder/vp9_ssim.c

+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+#include "vp9/encoder/vp9_onyx_int.h"
+
+void vp9_ssim_parms_16x16_c(unsigned char *s, int sp, unsigned char *r,
+                            int rp, unsigned long *sum_s, unsigned long *sum_r,
+                            unsigned long *sum_sq_s, unsigned long *sum_sq_r,
+                            unsigned long *sum_sxr) {
+  int i, j;
+  for (i = 0; i < 16; i++, s += sp, r += rp) {
+    for (j = 0; j < 16; j++) {
+      *sum_s += s[j];
+      *sum_r += r[j];
+      *sum_sq_s += s[j] * s[j];
+      *sum_sq_r += r[j] * r[j];
+      *sum_sxr += s[j] * r[j];
+    }
+  }
+}
+void vp9_ssim_parms_8x8_c(unsigned char *s, int sp, unsigned char *r, int rp,
+                          unsigned long *sum_s, unsigned long *sum_r,
+                          unsigned long *sum_sq_s, unsigned long *sum_sq_r,
+                          unsigned long *sum_sxr) {
+  int i, j;
+  for (i = 0; i < 8; i++, s += sp, r += rp) {
+    for (j = 0; j < 8; j++) {
+      *sum_s += s[j];
+      *sum_r += r[j];
+      *sum_sq_s += s[j] * s[j];
+      *sum_sq_r += r[j] * r[j];
+      *sum_sxr += s[j] * r[j];
+    }
+  }
+}
+
+const static int64_t cc1 =  26634; // (64^2*(.01*255)^2
+const static int64_t cc2 = 239708; // (64^2*(.03*255)^2
+
+static double similarity(unsigned long sum_s, unsigned long sum_r,
+                         unsigned long sum_sq_s, unsigned long sum_sq_r,
+                         unsigned long sum_sxr, int count) {
+  int64_t ssim_n, ssim_d;
+  int64_t c1, c2;
+
+  // scale the constants by number of pixels
+  c1 = (cc1 * count * count) >> 12;
+  c2 = (cc2 * count * count) >> 12;
+
+  ssim_n = (2 * sum_s * sum_r + c1) * ((int64_t) 2 * count * sum_sxr -
+                                       (int64_t) 2 * sum_s * sum_r + c2);
+
+  ssim_d = (sum_s * sum_s + sum_r * sum_r + c1) *
+           ((int64_t)count * sum_sq_s - (int64_t)sum_s * sum_s +
+            (int64_t)count * sum_sq_r - (int64_t) sum_r * sum_r + c2);
+
+  return ssim_n * 1.0 / ssim_d;
+}
+
+static double ssim_16x16(unsigned char *s, int sp, unsigned char *r, int rp) {
+  unsigned long sum_s = 0, sum_r = 0, sum_sq_s = 0, sum_sq_r = 0, sum_sxr = 0;
+  vp9_ssim_parms_16x16(s, sp, r, rp, &sum_s, &sum_r, &sum_sq_s, &sum_sq_r,
+                       &sum_sxr);
+  return similarity(sum_s, sum_r, sum_sq_s, sum_sq_r, sum_sxr, 256);
+}
+static double ssim_8x8(unsigned char *s, int sp, unsigned char *r, int rp) {
+  unsigned long sum_s = 0, sum_r = 0, sum_sq_s = 0, sum_sq_r = 0, sum_sxr = 0;
+  vp9_ssim_parms_8x8(s, sp, r, rp, &sum_s, &sum_r, &sum_sq_s, &sum_sq_r,
+                     &sum_sxr);
+  return similarity(sum_s, sum_r, sum_sq_s, sum_sq_r, sum_sxr, 64);
+}
+
+// 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 vp9_ssim2(unsigned char *img1, unsigned char *img2, int stride_img1,
+                 int stride_img2, int width, int height) {
+  int i, j;
+  int samples = 0;
+  double ssim_total = 0;
+
+  // 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) {
+      double v = ssim_8x8(img1 + j, stride_img1, img2 + j, stride_img2);
+      ssim_total += v;
+      samples++;
+    }
+  }
+  ssim_total /= samples;
+  return ssim_total;
+}
+double vp9_calc_ssim(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest,
+                     int lumamask, double *weight) {
+  double a, b, c;
+  double ssimv;
+
+  a = vp9_ssim2(source->y_buffer, dest->y_buffer,
+                source->y_stride, dest->y_stride, source->y_width,
+                source->y_height);
+
+  b = vp9_ssim2(source->u_buffer, dest->u_buffer,
+                source->uv_stride, dest->uv_stride, source->uv_width,
+                source->uv_height);
+
+  c = vp9_ssim2(source->v_buffer, dest->v_buffer,
+                source->uv_stride, dest->uv_stride, source->uv_width,
+                source->uv_height);
+
+  ssimv = a * .8 + .1 * (b + c);
+
+  *weight = 1;
+
+  return ssimv;
+}
+
+double vp9_calc_ssimg(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest,
+                      double *ssim_y, double *ssim_u, double *ssim_v) {
+  double ssim_all = 0;
+  double a, b, c;
+
+  a = vp9_ssim2(source->y_buffer, dest->y_buffer,
+                source->y_stride, dest->y_stride, source->y_width,
+                source->y_height);
+
+  b = vp9_ssim2(source->u_buffer, dest->u_buffer,
+                source->uv_stride, dest->uv_stride, source->uv_width,
+                source->uv_height);
+
+  c = vp9_ssim2(source->v_buffer, dest->v_buffer,
+                source->uv_stride, dest->uv_stride, source->uv_width,
+                source->uv_height);
+  *ssim_y = a;
+  *ssim_u = b;
+  *ssim_v = c;
+  ssim_all = (a * 4 + b + c) / 6;
+
+  return ssim_all;
+}