| /* |
| * Copyright (c) 2014 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_coding/neteq/audio_classifier.h" |
| |
| #include <assert.h> |
| #include <string.h> |
| |
| namespace webrtc { |
| |
| static const int kDefaultSampleRateHz = 48000; |
| static const int kDefaultFrameRateHz = 50; |
| static const int kDefaultFrameSizeSamples = |
| kDefaultSampleRateHz / kDefaultFrameRateHz; |
| static const float kDefaultThreshold = 0.5f; |
| |
| AudioClassifier::AudioClassifier() |
| : analysis_info_(), |
| is_music_(false), |
| music_probability_(0), |
| // This actually assigns the pointer to a static constant struct |
| // rather than creates a struct and |celt_mode_| does not need |
| // to be deleted. |
| celt_mode_(opus_custom_mode_create(kDefaultSampleRateHz, |
| kDefaultFrameSizeSamples, |
| NULL)), |
| analysis_state_() { |
| assert(celt_mode_); |
| } |
| |
| AudioClassifier::~AudioClassifier() {} |
| |
| bool AudioClassifier::Analysis(const int16_t* input, |
| int input_length, |
| int channels) { |
| // Must be 20 ms frames at 48 kHz sampling. |
| assert((input_length / channels) == kDefaultFrameSizeSamples); |
| |
| // Only mono or stereo are allowed. |
| assert(channels == 1 || channels == 2); |
| |
| // Call Opus' classifier, defined in |
| // "third_party/opus/src/src/analysis.h", with lsb_depth = 16. |
| // Also uses a down-mixing function downmix_int, defined in |
| // "third_party/opus/src/src/opus_private.h", with |
| // constants c1 = 0, and c2 = -2. |
| run_analysis(&analysis_state_, |
| celt_mode_, |
| input, |
| kDefaultFrameSizeSamples, |
| kDefaultFrameSizeSamples, |
| 0, |
| -2, |
| channels, |
| kDefaultSampleRateHz, |
| 16, |
| downmix_int, |
| &analysis_info_); |
| music_probability_ = analysis_info_.music_prob; |
| is_music_ = music_probability_ > kDefaultThreshold; |
| return is_music_; |
| } |
| |
| bool AudioClassifier::is_music() const { |
| return is_music_; |
| } |
| |
| } // namespace webrtc |