1/*
2 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3 *
4 *  Use of this source code is governed by a BSD-style license
5 *  that can be found in the LICENSE file in the root of the source
6 *  tree. An additional intellectual property rights grant can be found
7 *  in the file PATENTS.  All contributing project authors may
8 *  be found in the AUTHORS file in the root of the source tree.
9 */
10
11#include "webrtc/modules/audio_processing/vad/standalone_vad.h"
12
13#include <assert.h>
14
15#include "webrtc/modules/include/module_common_types.h"
16#include "webrtc/modules/utility/include/audio_frame_operations.h"
17#include "webrtc/typedefs.h"
18
19namespace webrtc {
20
21static const int kDefaultStandaloneVadMode = 3;
22
23StandaloneVad::StandaloneVad(VadInst* vad)
24    : vad_(vad), buffer_(), index_(0), mode_(kDefaultStandaloneVadMode) {
25}
26
27StandaloneVad::~StandaloneVad() {
28  WebRtcVad_Free(vad_);
29}
30
31StandaloneVad* StandaloneVad::Create() {
32  VadInst* vad = WebRtcVad_Create();
33  if (!vad)
34    return nullptr;
35
36  int err = WebRtcVad_Init(vad);
37  err |= WebRtcVad_set_mode(vad, kDefaultStandaloneVadMode);
38  if (err != 0) {
39    WebRtcVad_Free(vad);
40    return nullptr;
41  }
42  return new StandaloneVad(vad);
43}
44
45int StandaloneVad::AddAudio(const int16_t* data, size_t length) {
46  if (length != kLength10Ms)
47    return -1;
48
49  if (index_ + length > kLength10Ms * kMaxNum10msFrames)
50    // Reset the buffer if it's full.
51    // TODO(ajm): Instead, consider just processing every 10 ms frame. Then we
52    // can forgo the buffering.
53    index_ = 0;
54
55  memcpy(&buffer_[index_], data, sizeof(int16_t) * length);
56  index_ += length;
57  return 0;
58}
59
60int StandaloneVad::GetActivity(double* p, size_t length_p) {
61  if (index_ == 0)
62    return -1;
63
64  const size_t num_frames = index_ / kLength10Ms;
65  if (num_frames > length_p)
66    return -1;
67  assert(WebRtcVad_ValidRateAndFrameLength(kSampleRateHz, index_) == 0);
68
69  int activity = WebRtcVad_Process(vad_, kSampleRateHz, buffer_, index_);
70  if (activity < 0)
71    return -1;
72  else if (activity == 0)
73    p[0] = 0.01;  // Arbitrary but small and non-zero.
74  else
75    p[0] = 0.5;  // 0.5 is neutral values when combinned by other probabilities.
76  for (size_t n = 1; n < num_frames; n++)
77    p[n] = p[0];
78  // Reset the buffer to start from the beginning.
79  index_ = 0;
80  return activity;
81}
82
83int StandaloneVad::set_mode(int mode) {
84  if (mode < 0 || mode > 3)
85    return -1;
86  if (WebRtcVad_set_mode(vad_, mode) != 0)
87    return -1;
88
89  mode_ = mode;
90  return 0;
91}
92
93}  // namespace webrtc
94