[FFmpeg-devel] [PATCH] tests/tiny_ssim: fixed mistake in ssim_c1 calculation (PR #20251)

[FFmpeg-devel] [PATCH] tests/tiny_ssim: fixed mistake in ssim_c1 calculation (PR #20251)

[Valerii Zapodovnikov]

PR #20251 opened by Valerii Zapodovnikov (Balling)
URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20251
Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20251.patch

Closes #8529. Reporter uses this code in production.

Signed-off-by: Balling <val.zapod.vz@gmail.com>


From b8f32ee7615b3f09d089e03606c0657fe9a28108 Mon Sep 17 00:00:00 2001
From: Balling <val.zapod.vz@gmail.com>
Date: Fri, 15 Aug 2025 21:40:34 +0000
Subject: [PATCH] tests/tiny_ssim: fixed mistake in ssim_c1 calculation

Closes #8529. Reporter uses this code in production.

Signed-off-by: Balling <val.zapod.vz@gmail.com>
---
 tests/tiny_ssim.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tests/tiny_ssim.c b/tests/tiny_ssim.c
index 9740652288..8472fc3b19 100644
--- a/tests/tiny_ssim.c
+++ b/tests/tiny_ssim.c
@@ -79,11 +79,11 @@ static float ssim_end1( int s1, int s2, int ss, int s12 )
  * Maximum value for 9-bit is: ss*64 = (2^9-1)^2*16*4*64 = 1069551616, which will not overflow. */
 #if BIT_DEPTH > 9
     typedef float type;
-    static const float ssim_c1 = .01*.01*PIXEL_MAX*PIXEL_MAX*64;
+    static const float ssim_c1 = .01*.01*PIXEL_MAX*PIXEL_MAX*64*64;
     static const float ssim_c2 = .03*.03*PIXEL_MAX*PIXEL_MAX*64*63;
 #else
     typedef int type;
-    static const int ssim_c1 = (int)(.01*.01*PIXEL_MAX*PIXEL_MAX*64 + .5);
+    static const int ssim_c1 = (int)(.01*.01*PIXEL_MAX*PIXEL_MAX*64*64 + .5);
     static const int ssim_c2 = (int)(.03*.03*PIXEL_MAX*PIXEL_MAX*64*63 + .5);
 #endif
     type fs1 = s1;
-- 
2.49.1

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