lp_residual.h (1411B)
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 // Linear predictive coding (LPC) inverse filter length. 22 constexpr int 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 ArrayView<const float> x, 28 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(ArrayView<const float, kNumLpcCoefficients> lpc_coeffs, 34 ArrayView<const float> x, 35 ArrayView<float> y); 36 37 } // namespace rnn_vad 38 } // namespace webrtc 39 40 #endif // MODULES_AUDIO_PROCESSING_AGC2_RNN_VAD_LP_RESIDUAL_H_