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_ACCELERATE_H_ 12 #define MODULES_AUDIO_CODING_NETEQ_ACCELERATE_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 Accelerate operation. Most of the work is done 26 // in the base class TimeStretch, which is shared with the PreemptiveExpand 27 // operation. In the Accelerate class, the operations that are specific to 28 // Accelerate are implemented. 29 class Accelerate : public TimeStretch { 30 public: Accelerate(int sample_rate_hz,size_t num_channels,const BackgroundNoise & background_noise)31 Accelerate(int sample_rate_hz, 32 size_t num_channels, 33 const BackgroundNoise& background_noise) 34 : TimeStretch(sample_rate_hz, num_channels, background_noise) {} 35 36 // This method performs the actual Accelerate operation. The samples are 37 // read from |input|, of length |input_length| elements, and are written to 38 // |output|. The number of samples removed through time-stretching is 39 // is provided in the output |length_change_samples|. The method returns 40 // the outcome of the operation as an enumerator value. If |fast_accelerate| 41 // is true, the algorithm will relax the requirements on finding strong 42 // correlations, and may remove multiple pitch periods if possible. 43 ReturnCodes Process(const int16_t* input, 44 size_t input_length, 45 bool fast_accelerate, 46 AudioMultiVector* output, 47 size_t* length_change_samples); 48 49 protected: 50 // Sets the parameters |best_correlation| and |peak_index| to suitable 51 // values when the signal contains no active speech. 52 void SetParametersForPassiveSpeech(size_t len, 53 int16_t* best_correlation, 54 size_t* peak_index) const override; 55 56 // Checks the criteria for performing the time-stretching operation and, 57 // if possible, performs the time-stretching. 58 ReturnCodes CheckCriteriaAndStretch(const int16_t* input, 59 size_t input_length, 60 size_t peak_index, 61 int16_t best_correlation, 62 bool active_speech, 63 bool fast_mode, 64 AudioMultiVector* output) const override; 65 66 private: 67 RTC_DISALLOW_COPY_AND_ASSIGN(Accelerate); 68 }; 69 70 struct AccelerateFactory { AccelerateFactoryAccelerateFactory71 AccelerateFactory() {} ~AccelerateFactoryAccelerateFactory72 virtual ~AccelerateFactory() {} 73 74 virtual Accelerate* Create(int sample_rate_hz, 75 size_t num_channels, 76 const BackgroundNoise& background_noise) const; 77 }; 78 79 } // namespace webrtc 80 #endif // MODULES_AUDIO_CODING_NETEQ_ACCELERATE_H_ 81