1 /*
2  *  Copyright 2013 The LibYuv Project Authors. All rights reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS. All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  */
10 
11 // Get PSNR for video sequence. Assuming RAW 4:2:0 Y:Cb:Cr format
12 
13 #ifndef UTIL_PSNR_H_  // NOLINT
14 #define UTIL_PSNR_H_
15 
16 #include <math.h>  // For log10()
17 
18 #ifdef __cplusplus
19 extern "C" {
20 #endif
21 
22 #if !defined(INT_TYPES_DEFINED) && !defined(UINT8_TYPE_DEFINED)
23 typedef unsigned char uint8_t;
24 #define UINT8_TYPE_DEFINED
25 #endif
26 
27 static const double kMaxPSNR = 128.0;
28 
29 // libyuv provides this function when linking library for jpeg support.
30 // TODO(fbarchard): make psnr lib compatible subset of libyuv.
31 #if !defined(HAVE_JPEG)
32 // Computer Sum of Squared Error (SSE).
33 // Pass this to ComputePSNR for final result.
34 double ComputeSumSquareError(const uint8_t* src_a,
35                              const uint8_t* src_b,
36                              int count);
37 #endif
38 
39 // PSNR formula: psnr = 10 * log10 (Peak Signal^2 * size / sse)
40 // Returns 128.0 (kMaxPSNR) if sse is 0 (perfect match).
41 double ComputePSNR(double sse, double size);
42 
43 #ifdef __cplusplus
44 }  // extern "C"
45 #endif
46 
47 #endif  // UTIL_PSNR_H_  // NOLINT
48