shithub: libvpx

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ref: fc5d16678294a405de44da418474b119965dfb0f
parent: 509ec5945b7c42230dfae96ed6fa03d051a865d0
parent: 6dc612758cac7d4f07e58c020ee2a1422b49a26d
author: Sai Deng <[email protected]>
date: Wed Dec 5 12:55:58 EST 2018 

Merge "Fix overflow in calculating highbd SSIM"


--- a/tools/tiny_ssim.c
+++ b/tools/tiny_ssim.c
@@ -237,7 +237,7 @@
 static double similarity(uint32_t sum_s, uint32_t sum_r, uint32_t sum_sq_s,
                          uint32_t sum_sq_r, uint32_t sum_sxr, int count,
                          uint32_t bd) {
-  int64_t ssim_n, ssim_d;
+  double ssim_n, ssim_d;
   int64_t c1 = 0, c2 = 0;
   if (bd == 8) {
     // scale the constants by number of pixels
@@ -253,14 +253,14 @@
     assert(0);
   }
 
-  ssim_n = (2 * sum_s * sum_r + c1) *
-           ((int64_t)2 * count * sum_sxr - (int64_t)2 * sum_s * sum_r + c2);
+  ssim_n = (2.0 * sum_s * sum_r + c1) *
+           (2.0 * count * sum_sxr - 2.0 * 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);
+  ssim_d = ((double)sum_s * sum_s + (double)sum_r * sum_r + c1) *
+           ((double)count * sum_sq_s - (double)sum_s * sum_s +
+            (double)count * sum_sq_r - (double)sum_r * sum_r + c2);
 
-  return ssim_n * 1.0 / ssim_d;
+  return ssim_n / ssim_d;
 }
 
 static double ssim_8x8(const uint8_t *s, int sp, const uint8_t *r, int rp) {
--- a/vpx_dsp/ssim.c
+++ b/vpx_dsp/ssim.c
@@ -73,7 +73,7 @@
 static double similarity(uint32_t sum_s, uint32_t sum_r, uint32_t sum_sq_s,
                          uint32_t sum_sq_r, uint32_t sum_sxr, int count,
                          uint32_t bd) {
-  int64_t ssim_n, ssim_d;
+  double ssim_n, ssim_d;
   int64_t c1, c2;
   if (bd == 8) {
     // scale the constants by number of pixels
@@ -90,14 +90,14 @@
     assert(0);
   }
 
-  ssim_n = (2 * sum_s * sum_r + c1) *
-           ((int64_t)2 * count * sum_sxr - (int64_t)2 * sum_s * sum_r + c2);
+  ssim_n = (2.0 * sum_s * sum_r + c1) *
+           (2.0 * count * sum_sxr - 2.0 * 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);
+  ssim_d = ((double)sum_s * sum_s + (double)sum_r * sum_r + c1) *
+           ((double)count * sum_sq_s - (double)sum_s * sum_s +
+            (double)count * sum_sq_r - (double)sum_r * sum_r + c2);
 
-  return ssim_n * 1.0 / ssim_d;
+  return ssim_n / ssim_d;
 }
 
 static double ssim_8x8(const uint8_t *s, int sp, const uint8_t *r, int rp) {