1 /* 2 * Copyright (c) 2013 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 WEBRTC_MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 12 #define WEBRTC_MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 13 14 #include <deque> 15 #include <set> 16 17 #include "webrtc/base/scoped_ptr.h" 18 #include "webrtc/test/testsupport/gtest_prod_util.h" 19 #include "webrtc/typedefs.h" 20 21 namespace webrtc { 22 23 class TransientDetector; 24 25 // Detects transients in an audio stream and suppress them using a simple 26 // restoration algorithm that attenuates unexpected spikes in the spectrum. 27 class TransientSuppressor { 28 public: 29 TransientSuppressor(); 30 ~TransientSuppressor(); 31 32 int Initialize(int sample_rate_hz, int detector_rate_hz, int num_channels); 33 34 // Processes a |data| chunk, and returns it with keystrokes suppressed from 35 // it. The float format is assumed to be int16 ranged. If there are more than 36 // one channel, the chunks are concatenated one after the other in |data|. 37 // |data_length| must be equal to |data_length_|. 38 // |num_channels| must be equal to |num_channels_|. 39 // A sub-band, ideally the higher, can be used as |detection_data|. If it is 40 // NULL, |data| is used for the detection too. The |detection_data| is always 41 // assumed mono. 42 // If a reference signal (e.g. keyboard microphone) is available, it can be 43 // passed in as |reference_data|. It is assumed mono and must have the same 44 // length as |data|. NULL is accepted if unavailable. 45 // This suppressor performs better if voice information is available. 46 // |voice_probability| is the probability of voice being present in this chunk 47 // of audio. If voice information is not available, |voice_probability| must 48 // always be set to 1. 49 // |key_pressed| determines if a key was pressed on this audio chunk. 50 // Returns 0 on success and -1 otherwise. 51 int Suppress(float* data, 52 size_t data_length, 53 int num_channels, 54 const float* detection_data, 55 size_t detection_length, 56 const float* reference_data, 57 size_t reference_length, 58 float voice_probability, 59 bool key_pressed); 60 61 private: 62 FRIEND_TEST_ALL_PREFIXES(TransientSuppressorTest, 63 TypingDetectionLogicWorksAsExpectedForMono); 64 void Suppress(float* in_ptr, float* spectral_mean, float* out_ptr); 65 66 void UpdateKeypress(bool key_pressed); 67 void UpdateRestoration(float voice_probability); 68 69 void UpdateBuffers(float* data); 70 71 void HardRestoration(float* spectral_mean); 72 void SoftRestoration(float* spectral_mean); 73 74 rtc::scoped_ptr<TransientDetector> detector_; 75 76 size_t data_length_; 77 size_t detection_length_; 78 size_t analysis_length_; 79 size_t buffer_delay_; 80 size_t complex_analysis_length_; 81 int num_channels_; 82 // Input buffer where the original samples are stored. 83 rtc::scoped_ptr<float[]> in_buffer_; 84 rtc::scoped_ptr<float[]> detection_buffer_; 85 // Output buffer where the restored samples are stored. 86 rtc::scoped_ptr<float[]> out_buffer_; 87 88 // Arrays for fft. 89 rtc::scoped_ptr<size_t[]> ip_; 90 rtc::scoped_ptr<float[]> wfft_; 91 92 rtc::scoped_ptr<float[]> spectral_mean_; 93 94 // Stores the data for the fft. 95 rtc::scoped_ptr<float[]> fft_buffer_; 96 97 rtc::scoped_ptr<float[]> magnitudes_; 98 99 const float* window_; 100 101 rtc::scoped_ptr<float[]> mean_factor_; 102 103 float detector_smoothed_; 104 105 int keypress_counter_; 106 int chunks_since_keypress_; 107 bool detection_enabled_; 108 bool suppression_enabled_; 109 110 bool use_hard_restoration_; 111 int chunks_since_voice_change_; 112 113 uint32_t seed_; 114 115 bool using_reference_; 116 }; 117 118 } // namespace webrtc 119 120 #endif // WEBRTC_MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 121