1 /* 2 * Copyright (c) 2020 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_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 12 #define MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 13 14 #include <stddef.h> 15 #include <stdint.h> 16 #include <memory> 17 18 namespace webrtc { 19 20 // Detects transients in an audio stream and suppress them using a simple 21 // restoration algorithm that attenuates unexpected spikes in the spectrum. 22 class TransientSuppressor { 23 public: ~TransientSuppressor()24 virtual ~TransientSuppressor() {} 25 26 virtual int Initialize(int sample_rate_hz, 27 int detector_rate_hz, 28 int num_channels) = 0; 29 30 // Processes a |data| chunk, and returns it with keystrokes suppressed from 31 // it. The float format is assumed to be int16 ranged. If there are more than 32 // one channel, the chunks are concatenated one after the other in |data|. 33 // |data_length| must be equal to |data_length_|. 34 // |num_channels| must be equal to |num_channels_|. 35 // A sub-band, ideally the higher, can be used as |detection_data|. If it is 36 // NULL, |data| is used for the detection too. The |detection_data| is always 37 // assumed mono. 38 // If a reference signal (e.g. keyboard microphone) is available, it can be 39 // passed in as |reference_data|. It is assumed mono and must have the same 40 // length as |data|. NULL is accepted if unavailable. 41 // This suppressor performs better if voice information is available. 42 // |voice_probability| is the probability of voice being present in this chunk 43 // of audio. If voice information is not available, |voice_probability| must 44 // always be set to 1. 45 // |key_pressed| determines if a key was pressed on this audio chunk. 46 // Returns 0 on success and -1 otherwise. 47 virtual int Suppress(float* data, 48 size_t data_length, 49 int num_channels, 50 const float* detection_data, 51 size_t detection_length, 52 const float* reference_data, 53 size_t reference_length, 54 float voice_probability, 55 bool key_pressed) = 0; 56 }; 57 58 } // namespace webrtc 59 60 #endif // MODULES_AUDIO_PROCESSING_TRANSIENT_TRANSIENT_SUPPRESSOR_H_ 61