1 files changed, 93 insertions, 0 deletions
diff --git a/webrtc/modules/audio_processing/vad/standalone_vad.cc b/webrtc/modules/audio_processing/vad/standalone_vad.cc
new file mode 100644
index 0000000000..468b8ff3f0
--- /dev/null
+++ b/webrtc/modules/audio_processing/vad/standalone_vad.cc
@@ -0,0 +1,93 @@
+/*
+ *  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/vad/standalone_vad.h"
+
+#include <assert.h>
+
+#include "webrtc/modules/interface/module_common_types.h"
+#include "webrtc/modules/utility/interface/audio_frame_operations.h"
+#include "webrtc/typedefs.h"
+
+namespace webrtc {
+
+static const int kDefaultStandaloneVadMode = 3;
+
+StandaloneVad::StandaloneVad(VadInst* vad)
+    : vad_(vad), buffer_(), index_(0), mode_(kDefaultStandaloneVadMode) {
+}
+
+StandaloneVad::~StandaloneVad() {
+  WebRtcVad_Free(vad_);
+}
+
+StandaloneVad* StandaloneVad::Create() {
+  VadInst* vad = WebRtcVad_Create();
+  if (!vad)
+    return nullptr;
+
+  int err = WebRtcVad_Init(vad);
+  err |= WebRtcVad_set_mode(vad, kDefaultStandaloneVadMode);
+  if (err != 0) {
+    WebRtcVad_Free(vad);
+    return nullptr;
+  }
+  return new StandaloneVad(vad);
+}
+
+int StandaloneVad::AddAudio(const int16_t* data, size_t length) {
+  if (length != kLength10Ms)
+    return -1;
+
+  if (index_ + length > kLength10Ms * kMaxNum10msFrames)
+    // Reset the buffer if it's full.
+    // TODO(ajm): Instead, consider just processing every 10 ms frame. Then we
+    // can forgo the buffering.
+    index_ = 0;
+
+  memcpy(&buffer_[index_], data, sizeof(int16_t) * length);
+  index_ += length;
+  return 0;
+}
+
+int StandaloneVad::GetActivity(double* p, size_t length_p) {
+  if (index_ == 0)
+    return -1;
+
+  const size_t num_frames = index_ / kLength10Ms;
+  if (num_frames > length_p)
+    return -1;
+  assert(WebRtcVad_ValidRateAndFrameLength(kSampleRateHz, index_) == 0);
+
+  int activity = WebRtcVad_Process(vad_, kSampleRateHz, buffer_, index_);
+  if (activity < 0)
+    return -1;
+  else if (activity == 0)
+    p[0] = 0.01;  // Arbitrary but small and non-zero.
+  else
+    p[0] = 0.5;  // 0.5 is neutral values when combinned by other probabilities.
+  for (size_t n = 1; n < num_frames; n++)
+    p[n] = p[0];
+  // Reset the buffer to start from the beginning.
+  index_ = 0;
+  return activity;
+}
+
+int StandaloneVad::set_mode(int mode) {
+  if (mode < 0 || mode > 3)
+    return -1;
+  if (WebRtcVad_set_mode(vad_, mode) != 0)
+    return -1;
+
+  mode_ = mode;
+  return 0;
+}
+
+}  // namespace webrtc