michael@0: /*
michael@0:  *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0:  *
michael@0:  *  Use of this source code is governed by a BSD-style license
michael@0:  *  that can be found in the LICENSE file in the root of the source
michael@0:  *  tree. An additional intellectual property rights grant can be found
michael@0:  *  in the file PATENTS.  All contributing project authors may
michael@0:  *  be found in the AUTHORS file in the root of the source tree.
michael@0:  */
michael@0: 
michael@0: #include <math.h>
michael@0: 
michael@0: #include "vpx_scale/yv12config.h"
michael@0: 
michael@0: #define MAX_PSNR 100
michael@0: 
michael@0: double vp9_mse2psnr(double samples, double peak, double mse) {
michael@0:   double psnr;
michael@0: 
michael@0:   if (mse > 0.0)
michael@0:     psnr = 10.0 * log10(peak * peak * samples / mse);
michael@0:   else
michael@0:     psnr = MAX_PSNR;  // Limit to prevent / 0
michael@0: 
michael@0:   if (psnr > MAX_PSNR)
michael@0:     psnr = MAX_PSNR;
michael@0: 
michael@0:   return psnr;
michael@0: }