vp8/encoder/psnr.c

   1 /*
   2  *  Copyright (c) 2010 The WebM 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
  12 #include "vpx_scale/yv12config.h"
  13 #include "math.h"
  14 #include "systemdependent.h" /* for vp8_clear_system_state() */
  15
  16 #define MAX_PSNR 60
  17
  18 double vp8_mse2psnr(double Samples, double Peak, double Mse)
  19 {
  20     double psnr;
  21
  22     if ((double)Mse > 0.0)
  23         psnr = 10.0 * log10(Peak * Peak * Samples / Mse);
  24     else
  25         psnr = MAX_PSNR;      // Limit to prevent / 0
  26
  27     if (psnr > MAX_PSNR)
  28         psnr = MAX_PSNR;
  29
  30     return psnr;
  31 }
  32
  33 double vp8_calc_psnr(YV12_BUFFER_CONFIG *source, YV12_BUFFER_CONFIG *dest, double *YPsnr, double *UPsnr, double *VPsnr, double *sq_error)
  34 {
  35     int i, j;
  36     int Diff;
  37     double frame_psnr;
  38     double Total;
  39     double grand_total;
  40     unsigned char *src = source->y_buffer;
  41     unsigned char *dst = dest->y_buffer;
  42
  43     Total = 0.0;
  44     grand_total = 0.0;
  45
  46     // Loop throught the Y plane raw and reconstruction data summing (square differences)
  47     for (i = 0; i < source->y_height; i++)
  48     {
  49
  50         for (j = 0; j < source->y_width; j++)
  51         {
  52             Diff        = (int)(src[j]) - (int)(dst[j]);
  53             Total      += Diff * Diff;
  54         }
  55
  56         src += source->y_stride;
  57         dst += dest->y_stride;
  58     }
  59
  60     // Work out Y PSNR
  61     *YPsnr = vp8_mse2psnr(source->y_height * source->y_width, 255.0, Total);
  62     grand_total += Total;
  63     Total = 0;
  64
  65
  66     // Loop through the U plane
  67     src = source->u_buffer;
  68     dst = dest->u_buffer;
  69
  70     for (i = 0; i < source->uv_height; i++)
  71     {
  72
  73         for (j = 0; j < source->uv_width; j++)
  74         {
  75             Diff        = (int)(src[j]) - (int)(dst[j]);
  76             Total      += Diff * Diff;
  77         }
  78
  79         src += source->uv_stride;
  80         dst += dest->uv_stride;
  81     }
  82
  83     // Work out U PSNR
  84     *UPsnr = vp8_mse2psnr(source->uv_height * source->uv_width, 255.0, Total);
  85     grand_total += Total;
  86     Total = 0;
  87
  88
  89     // V PSNR
  90     src = source->v_buffer;
  91     dst = dest->v_buffer;
  92
  93     for (i = 0; i < source->uv_height; i++)
  94     {
  95
  96         for (j = 0; j < source->uv_width; j++)
  97         {
  98             Diff        = (int)(src[j]) - (int)(dst[j]);
  99             Total      += Diff * Diff;
 100         }
 101
 102         src += source->uv_stride;
 103         dst += dest->uv_stride;
 104     }
 105
 106     // Work out UV PSNR
 107     *VPsnr = vp8_mse2psnr(source->uv_height * source->uv_width, 255.0, Total);
 108     grand_total += Total;
 109     Total = 0;
 110
 111     // Work out total PSNR
 112     frame_psnr = vp8_mse2psnr(source->y_height * source->y_width * 3 / 2 , 255.0, grand_total);
 113
 114     *sq_error = 1.0 * grand_total;
 115
 116     return frame_psnr;
 117 }