voice-activity-detection.cc
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// 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;
}
}
}