tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
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standalone_vad.cc (2514B)

      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 "modules/audio_processing/vad/standalone_vad.h"
     12 
     13 #include <cstdint>
     14 #include <cstring>
     15 
     16 #include "common_audio/vad/include/webrtc_vad.h"
     17 #include "modules/audio_processing/vad/common.h"
     18 #include "rtc_base/checks.h"
     19 
     20 namespace webrtc {
     21 
     22 static const int kDefaultStandaloneVadMode = 3;
     23 
     24 StandaloneVad::StandaloneVad(VadInst* vad)
     25    : vad_(vad), buffer_(), index_(0), mode_(kDefaultStandaloneVadMode) {}
     26 
     27 StandaloneVad::~StandaloneVad() {
     28  WebRtcVad_Free(vad_);
     29 }
     30 
     31 StandaloneVad* 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 
     45 int 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 
     60 int 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  RTC_DCHECK_EQ(0, WebRtcVad_ValidRateAndFrameLength(kSampleRateHz, index_));
     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 
     83 int 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