1b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org/* 2b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved. 3b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * 4b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * Use of this source code is governed by a BSD-style license 5b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * that can be found in the LICENSE file in the root of the source 6b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * tree. An additional intellectual property rights grant can be found 7b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * in the file PATENTS. All contributing project authors may 8b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org * be found in the AUTHORS file in the root of the source tree. 9b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org */ 10b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 11b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 12b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// This file includes specific signal processing tools used in vad_core.c. 13b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 14b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#ifndef WEBRTC_COMMON_AUDIO_VAD_VAD_SP_H_ 15b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#define WEBRTC_COMMON_AUDIO_VAD_VAD_SP_H_ 16b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 17f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "webrtc/common_audio/vad/vad_core.h" 18f24ac5923cbe5e806fac59a0d15e32567553ce8epbos@webrtc.org#include "webrtc/typedefs.h" 19b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 20b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Downsamples the signal by a factor 2, eg. 32->16 or 16->8. 21b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 22b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Inputs: 23b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - signal_in : Input signal. 24b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - in_length : Length of input signal in samples. 25b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 26b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Input & Output: 27b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - filter_state : Current filter states of the two all-pass filters. The 28b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// |filter_state| is updated after all samples have been 29b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// processed. 30b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 31b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Output: 32b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - signal_out : Downsampled signal (of length |in_length| / 2). 33785c2fdd22c9ad2d172c0976d1224bbe44073bc7andrew@webrtc.orgvoid WebRtcVad_Downsampling(const int16_t* signal_in, 34b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int16_t* signal_out, 35b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int32_t* filter_state, 36b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int in_length); 37b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 38b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Updates and returns the smoothed feature minimum. As minimum we use the 39b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// median of the five smallest feature values in a 100 frames long window. 40b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// As long as |handle->frame_counter| is zero, that is, we haven't received any 41b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// "valid" data, FindMinimum() outputs the default value of 1600. 42b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 43b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Inputs: 44b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - feature_value : New feature value to update with. 45b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - channel : Channel number. 46b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 47b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Input & Output: 48b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// - handle : State information of the VAD. 49b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// 50b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// Returns: 51b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org// : Smoothed minimum value for a moving window. 52b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.orgint16_t WebRtcVad_FindMinimum(VadInstT* handle, 53b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int16_t feature_value, 54b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org int channel); 55b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org 56b015cbede88899f67a53fbbe581b02ce8e32794andrew@webrtc.org#endif // WEBRTC_COMMON_AUDIO_VAD_VAD_SP_H_ 57