Update common_audio

Corresponds to upstream commit 524e9b043e7e86fd72353b987c9d5f6a1ebf83e1

Update notes:

 * Moved src/ to webrtc/ to easily diff against the third_party/webrtc
   in the chromium tree

 * ARM/NEON/MIPS support is not yet hooked up

 * Tests have not been copied

webrtc/common_audio/vad/include/vad.h

@@ -0,0 +1,50 @@
+/*
+ *  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/base/scoped_ptr.h"
+#include "webrtc/common_audio/vad/include/webrtc_vad.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+class Vad {
+ public:
+  enum Aggressiveness {
+    kVadNormal = 0,
+    kVadLowBitrate = 1,
+    kVadAggressive = 2,
+    kVadVeryAggressive = 3
+  };
+
+  enum Activity { kPassive = 0, kActive = 1, kError = -1 };
+
+  virtual ~Vad() = default;
+
+  // Calculates a VAD decision for the given audio frame. Valid sample rates
+  // are 8000, 16000, and 32000 Hz; the number of samples must be such that the
+  // frame is 10, 20, or 30 ms long.
+  virtual Activity VoiceActivity(const int16_t* audio,
+                                 size_t num_samples,
+                                 int sample_rate_hz) = 0;
+
+  // Resets VAD state.
+  virtual void Reset() = 0;
+};
+
+// Returns a Vad instance that's implemented on top of WebRtcVad.
+rtc::scoped_ptr<Vad> CreateVad(Vad::Aggressiveness aggressiveness);
+
+}  // namespace webrtc
+
+#endif  // WEBRTC_COMMON_AUDIO_VAD_INCLUDE_VAD_H_

webrtc/common_audio/vad/include/webrtc_vad.h

@@ -0,0 +1,86 @@
+/*
+ *  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.
+ */
+
+
+/*
+ * This header file includes the VAD API calls. Specific function calls are given below.
+ */
+
+#ifndef WEBRTC_COMMON_AUDIO_VAD_INCLUDE_WEBRTC_VAD_H_  // NOLINT
+#define WEBRTC_COMMON_AUDIO_VAD_INCLUDE_WEBRTC_VAD_H_
+
+#include <stddef.h>
+
+#include "webrtc/typedefs.h"
+
+typedef struct WebRtcVadInst VadInst;
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Creates an instance to the VAD structure.
+VadInst* WebRtcVad_Create();
+
+// Frees the dynamic memory of a specified VAD instance.
+//
+// - handle [i] : Pointer to VAD instance that should be freed.
+void WebRtcVad_Free(VadInst* handle);
+
+// Initializes a VAD instance.
+//
+// - handle [i/o] : Instance that should be initialized.
+//
+// returns        : 0 - (OK),
+//                 -1 - (NULL pointer or Default mode could not be set).
+int WebRtcVad_Init(VadInst* handle);
+
+// Sets the VAD operating mode. A more aggressive (higher mode) VAD is more
+// restrictive in reporting speech. Put in other words the probability of being
+// speech when the VAD returns 1 is increased with increasing mode. As a
+// consequence also the missed detection rate goes up.
+//
+// - handle [i/o] : VAD instance.
+// - mode   [i]   : Aggressiveness mode (0, 1, 2, or 3).
+//
+// returns        : 0 - (OK),
+//                 -1 - (NULL pointer, mode could not be set or the VAD instance
+//                       has not been initialized).
+int WebRtcVad_set_mode(VadInst* handle, int mode);
+
+// Calculates a VAD decision for the |audio_frame|. For valid sampling rates
+// frame lengths, see the description of WebRtcVad_ValidRatesAndFrameLengths().
+//
+// - handle       [i/o] : VAD Instance. Needs to be initialized by
+//                        WebRtcVad_Init() before call.
+// - fs           [i]   : Sampling frequency (Hz): 8000, 16000, or 32000
+// - audio_frame  [i]   : Audio frame buffer.
+// - frame_length [i]   : Length of audio frame buffer in number of samples.
+//
+// returns              : 1 - (Active Voice),
+//                        0 - (Non-active Voice),
+//                       -1 - (Error)
+int WebRtcVad_Process(VadInst* handle, int fs, const int16_t* audio_frame,
+                      size_t frame_length);
+
+// Checks for valid combinations of |rate| and |frame_length|. We support 10,
+// 20 and 30 ms frames and the rates 8000, 16000 and 32000 Hz.
+//
+// - rate         [i] : Sampling frequency (Hz).
+// - frame_length [i] : Speech frame buffer length in number of samples.
+//
+// returns            : 0 - (valid combination), -1 - (invalid combination)
+int WebRtcVad_ValidRateAndFrameLength(int rate, size_t frame_length);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif  // WEBRTC_COMMON_AUDIO_VAD_INCLUDE_WEBRTC_VAD_H_  // NOLINT