1 /* 2 * Copyright (c) 2018 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_AGC2_RNN_VAD_LP_RESIDUAL_H_ 12 #define MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_LP_RESIDUAL_H_ 13 14 #include <stddef.h> 15 16 #include "api/array_view.h" 17 18 namespace webrtc { 19 namespace rnn_vad { 20 21 // LPC inverse filter length. 22 constexpr size_t kNumLpcCoefficients = 5; 23 24 // Given a frame |x|, computes a post-processed version of LPC coefficients 25 // tailored for pitch estimation. 26 void ComputeAndPostProcessLpcCoefficients( 27 rtc::ArrayView<const float> x, 28 rtc::ArrayView<float, kNumLpcCoefficients> lpc_coeffs); 29 30 // Computes the LP residual for the input frame |x| and the LPC coefficients 31 // |lpc_coeffs|. |y| and |x| can point to the same array for in-place 32 // computation. 33 void ComputeLpResidual( 34 rtc::ArrayView<const float, kNumLpcCoefficients> lpc_coeffs, 35 rtc::ArrayView<const float> x, 36 rtc::ArrayView<float> y); 37 38 } // namespace rnn_vad 39 } // namespace webrtc 40 41 #endif // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_LP_RESIDUAL_H_ 42