diff -r 000000000000 -r 6474c204b198 media/libvpx/vp8/encoder/psnr.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/media/libvpx/vp8/encoder/psnr.c	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+
+#include "vpx_scale/yv12config.h"
+#include "math.h"
+#include "vp8/common/systemdependent.h" /* for vp8_clear_system_state() */
+
+#define MAX_PSNR 100
+
+double vp8_mse2psnr(double Samples, double Peak, double Mse)
+{
+    double psnr;
+
+    if ((double)Mse > 0.0)
+        psnr = 10.0 * log10(Peak * Peak * Samples / Mse);
+    else
+        psnr = MAX_PSNR;      /* Limit to prevent / 0 */
+
+    if (psnr > MAX_PSNR)
+        psnr = MAX_PSNR;
+
+    return psnr;
+}