Merge "Adding vpx_sse_to_psnr() function."

3 files changed, 60 insertions, 0 deletions

diff --git a/vpx/internal/vpx_psnr.h b/vpx/internal/vpx_psnr.h
new file mode 100644
index 000000000..07d81bb8d
--- /dev/null
+++ b/vpx/internal/vpx_psnr.h
@@ -0,0 +1,34 @@
+/*
+ *  Copyright (c) 2014 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.
+ */
+
+#ifndef VPX_INTERNAL_VPX_PSNR_H_
+#define VPX_INTERNAL_VPX_PSNR_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// TODO(dkovalev) change vpx_sse_to_psnr signature: double -> int64_t
+
+/*!\brief Converts SSE to PSNR
+ *
+ * Converts sum of squared errros (SSE) to peak signal-to-noise ratio (PNSR).
+ *
+ * \param[in]    samples       Number of samples
+ * \param[in]    peak          Max sample value
+ * \param[in]    sse           Sum of squared errors
+ */
+double vpx_sse_to_psnr(double samples, double peak, double sse);
+
+#ifdef __cplusplus
+}  // extern "C"
+#endif
+
+#endif  // VPX_INTERNAL_VPX_PSNR_H_
diff --git a/vpx/src/vpx_psnr.c b/vpx/src/vpx_psnr.c
new file mode 100644
index 000000000..05843acb6
--- /dev/null
+++ b/vpx/src/vpx_psnr.c
@@ -0,0 +1,24 @@
+/*
+ *  Copyright (c) 2014 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 <math.h>
+
+#include "vpx/internal/vpx_psnr.h"
+
+#define MAX_PSNR 100.0
+
+double vpx_sse_to_psnr(double samples, double peak, double sse) {
+  if (sse > 0.0) {
+    const double psnr = 10.0 * log10(samples * peak * peak / sse);
+    return psnr > MAX_PSNR ? MAX_PSNR : psnr;
+  } else {
+    return MAX_PSNR;
+  }
+}
diff --git a/vpx/vpx_codec.mk b/vpx/vpx_codec.mk
index 111c87e53..98d1d567c 100644
--- a/vpx/vpx_codec.mk
+++ b/vpx/vpx_codec.mk
@@ -34,8 +34,10 @@ API_SRCS-yes                += vpx_decoder.h
 API_SRCS-yes                += src/vpx_encoder.c
 API_SRCS-yes                += vpx_encoder.h
 API_SRCS-yes                += internal/vpx_codec_internal.h
+API_SRCS-yes                += internal/vpx_psnr.h
 API_SRCS-yes                += src/vpx_codec.c
 API_SRCS-yes                += src/vpx_image.c
+API_SRCS-yes                += src/vpx_psnr.c
 API_SRCS-yes                += vpx_codec.h
 API_SRCS-yes                += vpx_codec.mk
 API_SRCS-yes                += vpx_frame_buffer.h