Merge audio_processing changes.

R=aluebs@webrtc.org, bjornv@webrtc.org
BUG=

Review URL: https://webrtc-codereview.appspot.com/32769004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7893 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_processing/agc/gmm_unittest.cc b/webrtc/modules/audio_processing/agc/gmm_unittest.cc
new file mode 100644
index 0000000..4ca658d
--- /dev/null
+++ b/webrtc/modules/audio_processing/agc/gmm_unittest.cc
@@ -0,0 +1,65 @@
+/*
+ *  Copyright (c) 2012 The WebRTC 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 "webrtc/modules/audio_processing/agc/gmm.h"
+
+#include <math.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/modules/audio_processing/agc/noise_gmm_tables.h"
+#include "webrtc/modules/audio_processing/agc/voice_gmm_tables.h"
+
+namespace webrtc {
+
+TEST(GmmTest, EvaluateGmm) {
+  GmmParameters noise_gmm;
+  GmmParameters voice_gmm;
+
+  // Setup noise GMM.
+  noise_gmm.dimension = kNoiseGmmDim;
+  noise_gmm.num_mixtures = kNoiseGmmNumMixtures;
+  noise_gmm.weight = kNoiseGmmWeights;
+  noise_gmm.mean = &kNoiseGmmMean[0][0];
+  noise_gmm.covar_inverse = &kNoiseGmmCovarInverse[0][0][0];
+
+  // Setup voice GMM.
+  voice_gmm.dimension = kVoiceGmmDim;
+  voice_gmm.num_mixtures = kVoiceGmmNumMixtures;
+  voice_gmm.weight = kVoiceGmmWeights;
+  voice_gmm.mean = &kVoiceGmmMean[0][0];
+  voice_gmm.covar_inverse = &kVoiceGmmCovarInverse[0][0][0];
+
+  // Test vectors. These are the mean of the GMM means.
+  const double kXVoice[kVoiceGmmDim] = {
+      -1.35893162459863, 602.862491970368, 178.022069191324};
+  const double kXNoise[kNoiseGmmDim] = {
+      -2.33443722724409, 2827.97828765184, 141.114178166812};
+
+  // Expected pdf values. These values are computed in MATLAB using EvalGmm.m
+  const double kPdfNoise = 1.88904409403101e-07;
+  const double kPdfVoice = 1.30453996982266e-06;
+
+  // Relative error should be smaller that the following value.
+  const double kAcceptedRelativeErr = 1e-10;
+
+  // Test Voice.
+  double pdf = EvaluateGmm(kXVoice, voice_gmm);
+  EXPECT_GT(pdf, 0);
+  double relative_error = fabs(pdf - kPdfVoice) / kPdfVoice;
+  EXPECT_LE(relative_error, kAcceptedRelativeErr);
+
+  // Test Noise.
+  pdf = EvaluateGmm(kXNoise, noise_gmm);
+  EXPECT_GT(pdf, 0);
+  relative_error = fabs(pdf - kPdfNoise) / kPdfNoise;
+  EXPECT_LE(relative_error, kAcceptedRelativeErr);
+}
+
+}  // namespace webrtc