1 /* 2 * Copyright (c) 2022 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_VOICE_PROBABILITY_DELAY_UNIT_H_ 12 #define MODULES_AUDIO_PROCESSING_TRANSIENT_VOICE_PROBABILITY_DELAY_UNIT_H_ 13 14 #include <array> 15 16 namespace webrtc { 17 18 // Iteratively produces a sequence of delayed voice probability values given a 19 // fixed delay between 0 and 20 ms and given a sequence of voice probability 20 // values observed every 10 ms. Supports fractional delays, that are delays 21 // which are not a multiple integer of 10 ms. Applies interpolation with 22 // fractional delays; otherwise, returns a previously observed value according 23 // to the given fixed delay. 24 class VoiceProbabilityDelayUnit { 25 public: 26 // Ctor. `delay_num_samples` is the delay in number of samples and it must be 27 // non-negative and less than 20 ms. 28 VoiceProbabilityDelayUnit(int delay_num_samples, int sample_rate_hz); 29 30 // Handles delay and sample rate changes and resets the delay unit. 31 void Initialize(int delay_num_samples, int sample_rate_hz); 32 33 // Observes `voice_probability` and returns a delayed voice probability. 34 float Delay(float voice_probability); 35 36 private: 37 std::array<float, 3> weights_; 38 std::array<float, 2> last_probabilities_; 39 }; 40 41 } // namespace webrtc 42 43 #endif // MODULES_AUDIO_PROCESSING_TRANSIENT_VOICE_PROBABILITY_DELAY_UNIT_H_ 44