webrtc/common_audio/vad/main/source/vad_sp.h

61 lines
1.8 KiB
C

/*
* Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
/*
* This header file includes the VAD internal calls for Downsampling and FindMinimum.
* Specific function calls are given below.
*/
#ifndef WEBRTC_VAD_SP_H_
#define WEBRTC_VAD_SP_H_
#include "vad_core.h"
/****************************************************************************
* WebRtcVad_Downsampling(...)
*
* Downsamples the signal a factor 2, eg. 32->16 or 16->8
*
* Input:
* - signal_in : Input signal
* - in_length : Length of input signal in samples
*
* Input & Output:
* - filter_state : Filter state for first all-pass filters
*
* Output:
* - signal_out : Downsampled signal (of length len/2)
*/
void WebRtcVad_Downsampling(WebRtc_Word16* signal_in,
WebRtc_Word16* signal_out,
WebRtc_Word32* filter_state,
int in_length);
/****************************************************************************
* WebRtcVad_FindMinimum(...)
*
* Find the five lowest values of x in 100 frames long window. Return a mean
* value of these five values.
*
* Input:
* - feature_value : Feature value
* - channel : Channel number
*
* Input & Output:
* - inst : State information
*
* Output:
* return value : Weighted minimum value for a moving window.
*/
WebRtc_Word16 WebRtcVad_FindMinimum(VadInstT* inst, WebRtc_Word16 feature_value, int channel);
#endif // WEBRTC_VAD_SP_H_