Blame view

src/ivector/voice-activity-detection.cc 2.12 KB
8dcb6dfcb   Yannick Estève   first commit
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
  // ivector/voice-activity-detection.cc
  
  // Copyright     2013  Daniel Povey
  
  // See ../../COPYING for clarification regarding multiple authors
  //
  // Licensed under the Apache License, Version 2.0 (the "License");
  // you may not use this file except in compliance with the License.
  // You may obtain a copy of the License at
  //
  //  http://www.apache.org/licenses/LICENSE-2.0
  //
  // THIS CODE IS PROVIDED *AS IS* BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
  // KIND, EITHER EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION ANY IMPLIED
  // WARRANTIES OR CONDITIONS OF TITLE, FITNESS FOR A PARTICULAR PURPOSE,
  // MERCHANTABLITY OR NON-INFRINGEMENT.
  // See the Apache 2 License for the specific language governing permissions and
  // limitations under the License.
  
  
  #include "ivector/voice-activity-detection.h"
  #include "matrix/matrix-functions.h"
  
  
  namespace kaldi {
  
  void ComputeVadEnergy(const VadEnergyOptions &opts,
                        const MatrixBase<BaseFloat> &feats,
                        Vector<BaseFloat> *output_voiced) {
    int32 T = feats.NumRows();
    output_voiced->Resize(T);
    if (T == 0) {
      KALDI_WARN << "Empty features";
      return;
    }
    Vector<BaseFloat> log_energy(T);
    log_energy.CopyColFromMat(feats, 0); // column zero is log-energy.
    
    BaseFloat energy_threshold = opts.vad_energy_threshold;
    if (opts.vad_energy_mean_scale != 0.0) {
      KALDI_ASSERT(opts.vad_energy_mean_scale > 0.0);
      energy_threshold += opts.vad_energy_mean_scale * log_energy.Sum() / T;
    }
    
    KALDI_ASSERT(opts.vad_frames_context >= 0);
    KALDI_ASSERT(opts.vad_proportion_threshold > 0.0 &&
                 opts.vad_proportion_threshold < 1.0);
    for (int32 t = 0; t < T; t++) {
      const BaseFloat *log_energy_data = log_energy.Data();
      int32 num_count = 0, den_count = 0, context = opts.vad_frames_context;
      for (int32 t2 = t - context; t2 <= t + context; t2++) {
        if (t2 >= 0 && t2 < T) {
          den_count++;
          if (log_energy_data[t2] > energy_threshold)
            num_count++;
        }
      }
      if (num_count >= den_count * opts.vad_proportion_threshold)
        (*output_voiced)(t) = 1.0;
      else
        (*output_voiced)(t) = 0.0;
    }
  }  
  
  }