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 #ifndef MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_ 12 #define MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_ 13 14 #include <stddef.h> 15 #include <stdint.h> 16 17 #include "modules/audio_coding/neteq/time_stretch.h" 18 #include "rtc_base/constructor_magic.h" 19 20 namespace webrtc { 21 22 class AudioMultiVector; 23 class BackgroundNoise; 24 25 // This class implements the PreemptiveExpand operation. Most of the work is 26 // done in the base class TimeStretch, which is shared with the Accelerate 27 // operation. In the PreemptiveExpand class, the operations that are specific to 28 // PreemptiveExpand are implemented. 29 class PreemptiveExpand : public TimeStretch { 30 public: PreemptiveExpand(int sample_rate_hz,size_t num_channels,const BackgroundNoise & background_noise,size_t overlap_samples)31 PreemptiveExpand(int sample_rate_hz, 32 size_t num_channels, 33 const BackgroundNoise& background_noise, 34 size_t overlap_samples) 35 : TimeStretch(sample_rate_hz, num_channels, background_noise), 36 old_data_length_per_channel_(0), 37 overlap_samples_(overlap_samples) {} 38 39 // This method performs the actual PreemptiveExpand operation. The samples are 40 // read from |input|, of length |input_length| elements, and are written to 41 // |output|. The number of samples added through time-stretching is 42 // is provided in the output |length_change_samples|. The method returns 43 // the outcome of the operation as an enumerator value. 44 ReturnCodes Process(const int16_t* pw16_decoded, 45 size_t len, 46 size_t old_data_len, 47 AudioMultiVector* output, 48 size_t* length_change_samples); 49 50 protected: 51 // Sets the parameters |best_correlation| and |peak_index| to suitable 52 // values when the signal contains no active speech. 53 void SetParametersForPassiveSpeech(size_t input_length, 54 int16_t* best_correlation, 55 size_t* peak_index) const override; 56 57 // Checks the criteria for performing the time-stretching operation and, 58 // if possible, performs the time-stretching. 59 ReturnCodes CheckCriteriaAndStretch(const int16_t* input, 60 size_t input_length, 61 size_t peak_index, 62 int16_t best_correlation, 63 bool active_speech, 64 bool /*fast_mode*/, 65 AudioMultiVector* output) const override; 66 67 private: 68 size_t old_data_length_per_channel_; 69 size_t overlap_samples_; 70 71 RTC_DISALLOW_COPY_AND_ASSIGN(PreemptiveExpand); 72 }; 73 74 struct PreemptiveExpandFactory { PreemptiveExpandFactoryPreemptiveExpandFactory75 PreemptiveExpandFactory() {} ~PreemptiveExpandFactoryPreemptiveExpandFactory76 virtual ~PreemptiveExpandFactory() {} 77 78 virtual PreemptiveExpand* Create(int sample_rate_hz, 79 size_t num_channels, 80 const BackgroundNoise& background_noise, 81 size_t overlap_samples) const; 82 }; 83 84 } // namespace webrtc 85 #endif // MODULES_AUDIO_CODING_NETEQ_PREEMPTIVE_EXPAND_H_ 86