Creating a C++ wrapper class for VAD

Also adding a mock. This work is part of an ongoing effort to
encapsulate encoders in AudioEncoder classes. The CNG encoder will also
be implemented as an AudioEncoder class, and will also contain a VAD
C++ wrapper.

BUG=3926
R=bjornv@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/27839004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@7570 4adac7df-926f-26a2-2b94-8c16560cd09d

webrtc/common_audio/BUILD.gn

@@ -71,7 +71,9 @@ source_set("common_audio") {
     "signal_processing/splitting_filter.c",
     "signal_processing/sqrt_of_one_minus_x_squared.c",
     "signal_processing/vector_scaling_operations.c",
+    "vad/include/vad.h",
     "vad/include/webrtc_vad.h",
+    "vad/vad.cc",
     "vad/webrtc_vad.c",
     "vad/vad_core.c",
     "vad/vad_core.h",

webrtc/common_audio/common_audio.gyp

@@ -85,7 +85,9 @@
         'signal_processing/splitting_filter.c',
         'signal_processing/sqrt_of_one_minus_x_squared.c',
         'signal_processing/vector_scaling_operations.c',
+        'vad/include/vad.h',
         'vad/include/webrtc_vad.h',
+        'vad/vad.cc',
         'vad/webrtc_vad.c',
         'vad/vad_core.c',
         'vad/vad_core.h',

webrtc/common_audio/vad/include/vad.h

@@ -0,0 +1,45 @@
+/*
+ *  Copyright (c) 2014 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.
+ */
+
+#ifndef WEBRTC_COMMON_AUDIO_VAD_INCLUDE_VAD_H_
+#define WEBRTC_COMMON_AUDIO_VAD_INCLUDE_VAD_H_
+
+#include "webrtc/base/checks.h"
+#include "webrtc/common_audio/vad/include/webrtc_vad.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+// This is a C++ wrapper class for WebRtcVad.
+class Vad {
+ public:
+  enum Aggressiveness {
+    kVadNormal = 0,
+    kVadLowBitrate = 1,
+    kVadAggressive = 2,
+    kVadVeryAggressive = 3
+  };
+
+  enum Activity { kPassive = 0, kActive = 1, kError = -1 };
+
+  explicit Vad(enum Aggressiveness mode);
+
+  virtual ~Vad();
+
+  enum Activity VoiceActivity(const int16_t* audio,
+                              size_t num_samples,
+                              int sample_rate_hz);
+
+ private:
+  VadInst* handle_;
+};
+
+}  // namespace webrtc
+#endif  // WEBRTC_COMMON_AUDIO_VAD_INCLUDE_VAD_H_

webrtc/common_audio/vad/mock/mock_vad.h

@@ -0,0 +1,34 @@
+/*
+ *  Copyright (c) 2014 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.
+ */
+
+#ifndef WEBRTC_COMMON_AUDIO_VAD_MOCK_MOCK_VAD_H_
+#define WEBRTC_COMMON_AUDIO_VAD_MOCK_MOCK_VAD_H_
+
+#include "webrtc/common_audio/vad/include/vad.h"
+
+#include "testing/gmock/include/gmock/gmock.h"
+
+namespace webrtc {
+
+class MockVad : public Vad {
+ public:
+  explicit MockVad(enum Aggressiveness mode) {}
+  virtual ~MockVad() { Die(); }
+  MOCK_METHOD0(Die, void());
+
+  MOCK_METHOD3(VoiceActivity,
+               enum Activity(const int16_t* audio,
+                             size_t num_samples,
+                             int sample_rate_hz));
+};
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_COMMON_AUDIO_VAD_MOCK_MOCK_VAD_H_

webrtc/common_audio/vad/vad.cc

@@ -0,0 +1,43 @@
+/*
+ *  Copyright (c) 2014 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/common_audio/vad/include/vad.h"
+
+#include "webrtc/base/checks.h"
+
+namespace webrtc {
+
+Vad::Vad(enum Aggressiveness mode) {
+  CHECK_EQ(WebRtcVad_Create(&handle_), 0);
+  CHECK_EQ(WebRtcVad_Init(handle_), 0);
+  CHECK_EQ(WebRtcVad_set_mode(handle_, mode), 0);
+}
+
+Vad::~Vad() {
+  WebRtcVad_Free(handle_);
+}
+
+enum Vad::Activity Vad::VoiceActivity(const int16_t* audio,
+                                      size_t num_samples,
+                                      int sample_rate_hz) {
+  int ret = WebRtcVad_Process(
+      handle_, sample_rate_hz, audio, static_cast<int>(num_samples));
+  switch (ret) {
+    case 0:
+      return kPassive;
+    case 1:
+      return kActive;
+    default:
+      DCHECK(false) << "WebRtcVad_Process returned an error.";
+      return kError;
+  }
+}
+
+}  // namespace webrtc