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/*
* Copyright (c) 2012 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.
*/
#ifndef MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSION_H_
#define MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSION_H_
#include <stddef.h>
#include "typedefs.h" // NOLINT(build/include)
typedef struct NsHandleT NsHandle;
#ifdef __cplusplus
extern "C" {
#endif
/*
* This function creates an instance of the floating point Noise Suppression.
*/
NsHandle* WebRtcNs_Create(void);
/*
* This function frees the dynamic memory of a specified noise suppression
* instance.
*
* Input:
* - NS_inst : Pointer to NS instance that should be freed
*/
void WebRtcNs_Free(NsHandle* NS_inst);
/*
* This function initializes a NS instance and has to be called before any other
* processing is made.
*
* Input:
* - NS_inst : Instance that should be initialized
* - fs : sampling frequency
*
* Output:
* - NS_inst : Initialized instance
*
* Return value : 0 - Ok
* -1 - Error
*/
int WebRtcNs_Init(NsHandle* NS_inst, uint32_t fs);
/*
* This changes the aggressiveness of the noise suppression method.
*
* Input:
* - NS_inst : Noise suppression instance.
* - mode : 0: Mild, 1: Medium , 2: Aggressive
*
* Output:
* - NS_inst : Updated instance.
*
* Return value : 0 - Ok
* -1 - Error
*/
int WebRtcNs_set_policy(NsHandle* NS_inst, int mode);
/*
* This functions estimates the background noise for the inserted speech frame.
* The input and output signals should always be 10ms (80 or 160 samples).
*
* Input
* - NS_inst : Noise suppression instance.
* - spframe : Pointer to speech frame buffer for L band
*
* Output:
* - NS_inst : Updated NS instance
*/
void WebRtcNs_Analyze(NsHandle* NS_inst, const float* spframe);
/*
* This functions does Noise Suppression for the inserted speech frame. The
* input and output signals should always be 10ms (80 or 160 samples).
*
* Input
* - NS_inst : Noise suppression instance.
* - spframe : Pointer to speech frame buffer for each band
* - num_bands : Number of bands
*
* Output:
* - NS_inst : Updated NS instance
* - outframe : Pointer to output frame for each band
*/
void WebRtcNs_Process(NsHandle* NS_inst,
const float* const* spframe,
size_t num_bands,
float* const* outframe);
/* Returns the internally used prior speech probability of the current frame.
* There is a frequency bin based one as well, with which this should not be
* confused.
*
* Input
* - handle : Noise suppression instance.
*
* Return value : Prior speech probability in interval [0.0, 1.0].
* -1 - NULL pointer or uninitialized instance.
*/
float WebRtcNs_prior_speech_probability(NsHandle* handle);
/* Returns a pointer to the noise estimate per frequency bin. The number of
* frequency bins can be provided using WebRtcNs_num_freq().
*
* Input
* - handle : Noise suppression instance.
*
* Return value : Pointer to the noise estimate per frequency bin.
* Returns NULL if the input is a NULL pointer or an
* uninitialized instance.
*/
const float* WebRtcNs_noise_estimate(const NsHandle* handle);
/* Returns the number of frequency bins, which is the length of the noise
* estimate for example.
*
* Return value : Number of frequency bins.
*/
size_t WebRtcNs_num_freq(void);
#ifdef __cplusplus
}
#endif
#endif // MODULES_AUDIO_PROCESSING_NS_NOISE_SUPPRESSION_H_