shithub: libvpx

Download patch

ref: d931eb556b414e6c4176cb5b94cc5c31519d7360
parent: ac858f0a78d97a8cf4d4fb41d11d015fddb4024a
author: sdeng <sdeng@google.com>
date: Thu Dec 13 11:47:10 EST 2018 

No need to shift in SSIM calculations

We only need to shift in the encoder when the input bit depth
does not equal to the encoder internal bit depth.

Change-Id: If9af62382ac6824f33dc7dcdd3d3ff7802b92e9a


--- a/tools/tiny_ssim.c
+++ b/tools/tiny_ssim.c
@@ -272,12 +272,11 @@
 
 #if CONFIG_VP9_HIGHBITDEPTH
 static double highbd_ssim_8x8(const uint16_t *s, int sp, const uint16_t *r,
-                              int rp, uint32_t bd, uint32_t shift) {
+                              int rp, uint32_t bd) {
   uint32_t sum_s = 0, sum_r = 0, sum_sq_s = 0, sum_sq_r = 0, sum_sxr = 0;
   highbd_ssim_parms_8x8(s, sp, r, rp, &sum_s, &sum_r, &sum_sq_s, &sum_sq_r,
                         &sum_sxr);
-  return similarity(sum_s >> shift, sum_r >> shift, sum_sq_s >> (2 * shift),
-                    sum_sq_r >> (2 * shift), sum_sxr >> (2 * shift), 64, bd);
+  return similarity(sum_s, sum_r, sum_sq_s, sum_sq_r, sum_sxr, 64, bd);
 }
 #endif  // CONFIG_VP9_HIGHBITDEPTH
 
@@ -306,7 +305,7 @@
 #if CONFIG_VP9_HIGHBITDEPTH
 static double highbd_ssim2(const uint8_t *img1, const uint8_t *img2,
                            int stride_img1, int stride_img2, int width,
-                           int height, uint32_t bd, uint32_t shift) {
+                           int height, uint32_t bd) {
   int i, j;
   int samples = 0;
   double ssim_total = 0;
@@ -315,9 +314,9 @@
   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 = highbd_ssim_8x8(CONVERT_TO_SHORTPTR(img1 + j), stride_img1,
-                                 CONVERT_TO_SHORTPTR(img2 + j), stride_img2, bd,
-                                 shift);
+      double v =
+          highbd_ssim_8x8(CONVERT_TO_SHORTPTR(img1 + j), stride_img1,
+                          CONVERT_TO_SHORTPTR(img2 + j), stride_img2, bd);
       ssim_total += v;
       samples++;
     }
@@ -688,7 +687,7 @@
     psnr = calc_plane_error(buf0, w, buf1, w, w, h);                           \
   } else {                                                                     \
     ssim = highbd_ssim2(CONVERT_TO_BYTEPTR(buf0), CONVERT_TO_BYTEPTR(buf1), w, \
-                        w, w, h, bit_depth, bit_depth - 8);                    \
+                        w, w, h, bit_depth);                                   \
     psnr = calc_plane_error16(CAST_TO_SHORTPTR(buf0), w,                       \
                               CAST_TO_SHORTPTR(buf1), w, w, h);                \
   }