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      1 /*
      2  *  Copyright (c) 2011 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 WEBRTC_MODULES_AUDIO_PROCESSING_NS_NS_CORE_H_
     12 #define WEBRTC_MODULES_AUDIO_PROCESSING_NS_NS_CORE_H_
     13 
     14 #include "webrtc/modules/audio_processing/ns/defines.h"
     15 
     16 typedef struct NSParaExtract_ {
     17   // Bin size of histogram.
     18   float binSizeLrt;
     19   float binSizeSpecFlat;
     20   float binSizeSpecDiff;
     21   // Range of histogram over which LRT threshold is computed.
     22   float rangeAvgHistLrt;
     23   // Scale parameters: multiply dominant peaks of the histograms by scale factor
     24   // to obtain thresholds for prior model.
     25   float factor1ModelPars;  // For LRT and spectral difference.
     26   float factor2ModelPars;  // For spectral_flatness: used when noise is flatter
     27                            // than speech.
     28   // Peak limit for spectral flatness (varies between 0 and 1).
     29   float thresPosSpecFlat;
     30   // Limit on spacing of two highest peaks in histogram: spacing determined by
     31   // bin size.
     32   float limitPeakSpacingSpecFlat;
     33   float limitPeakSpacingSpecDiff;
     34   // Limit on relevance of second peak.
     35   float limitPeakWeightsSpecFlat;
     36   float limitPeakWeightsSpecDiff;
     37   // Limit on fluctuation of LRT feature.
     38   float thresFluctLrt;
     39   // Limit on the max and min values for the feature thresholds.
     40   float maxLrt;
     41   float minLrt;
     42   float maxSpecFlat;
     43   float minSpecFlat;
     44   float maxSpecDiff;
     45   float minSpecDiff;
     46   // Criteria of weight of histogram peak to accept/reject feature.
     47   int thresWeightSpecFlat;
     48   int thresWeightSpecDiff;
     49 
     50 } NSParaExtract;
     51 
     52 typedef struct NoiseSuppressionC_ {
     53   uint32_t fs;
     54   size_t blockLen;
     55   size_t windShift;
     56   size_t anaLen;
     57   size_t magnLen;
     58   int aggrMode;
     59   const float* window;
     60   float analyzeBuf[ANAL_BLOCKL_MAX];
     61   float dataBuf[ANAL_BLOCKL_MAX];
     62   float syntBuf[ANAL_BLOCKL_MAX];
     63 
     64   int initFlag;
     65   // Parameters for quantile noise estimation.
     66   float density[SIMULT * HALF_ANAL_BLOCKL];
     67   float lquantile[SIMULT * HALF_ANAL_BLOCKL];
     68   float quantile[HALF_ANAL_BLOCKL];
     69   int counter[SIMULT];
     70   int updates;
     71   // Parameters for Wiener filter.
     72   float smooth[HALF_ANAL_BLOCKL];
     73   float overdrive;
     74   float denoiseBound;
     75   int gainmap;
     76   // FFT work arrays.
     77   size_t ip[IP_LENGTH];
     78   float wfft[W_LENGTH];
     79 
     80   // Parameters for new method: some not needed, will reduce/cleanup later.
     81   int32_t blockInd;  // Frame index counter.
     82   int modelUpdatePars[4];  // Parameters for updating or estimating.
     83   // Thresholds/weights for prior model.
     84   float priorModelPars[7];  // Parameters for prior model.
     85   float noise[HALF_ANAL_BLOCKL];  // Noise spectrum from current frame.
     86   float noisePrev[HALF_ANAL_BLOCKL];  // Noise spectrum from previous frame.
     87   // Magnitude spectrum of previous analyze frame.
     88   float magnPrevAnalyze[HALF_ANAL_BLOCKL];
     89   // Magnitude spectrum of previous process frame.
     90   float magnPrevProcess[HALF_ANAL_BLOCKL];
     91   float logLrtTimeAvg[HALF_ANAL_BLOCKL];  // Log LRT factor with time-smoothing.
     92   float priorSpeechProb;  // Prior speech/noise probability.
     93   float featureData[7];
     94   // Conservative noise spectrum estimate.
     95   float magnAvgPause[HALF_ANAL_BLOCKL];
     96   float signalEnergy;  // Energy of |magn|.
     97   float sumMagn;
     98   float whiteNoiseLevel;  // Initial noise estimate.
     99   float initMagnEst[HALF_ANAL_BLOCKL];  // Initial magnitude spectrum estimate.
    100   float pinkNoiseNumerator;  // Pink noise parameter: numerator.
    101   float pinkNoiseExp;  // Pink noise parameter: power of frequencies.
    102   float parametricNoise[HALF_ANAL_BLOCKL];
    103   // Parameters for feature extraction.
    104   NSParaExtract featureExtractionParams;
    105   // Histograms for parameter estimation.
    106   int histLrt[HIST_PAR_EST];
    107   int histSpecFlat[HIST_PAR_EST];
    108   int histSpecDiff[HIST_PAR_EST];
    109   // Quantities for high band estimate.
    110   float speechProb[HALF_ANAL_BLOCKL];  // Final speech/noise prob: prior + LRT.
    111   // Buffering data for HB.
    112   float dataBufHB[NUM_HIGH_BANDS_MAX][ANAL_BLOCKL_MAX];
    113 
    114 } NoiseSuppressionC;
    115 
    116 #ifdef __cplusplus
    117 extern "C" {
    118 #endif
    119 
    120 /****************************************************************************
    121  * WebRtcNs_InitCore(...)
    122  *
    123  * This function initializes a noise suppression instance
    124  *
    125  * Input:
    126  *      - self          : Instance that should be initialized
    127  *      - fs            : Sampling frequency
    128  *
    129  * Output:
    130  *      - self          : Initialized instance
    131  *
    132  * Return value         :  0 - Ok
    133  *                        -1 - Error
    134  */
    135 int WebRtcNs_InitCore(NoiseSuppressionC* self, uint32_t fs);
    136 
    137 /****************************************************************************
    138  * WebRtcNs_set_policy_core(...)
    139  *
    140  * This changes the aggressiveness of the noise suppression method.
    141  *
    142  * Input:
    143  *      - self          : Instance that should be initialized
    144  *      - mode          : 0: Mild (6dB), 1: Medium (10dB), 2: Aggressive (15dB)
    145  *
    146  * Output:
    147  *      - self          : Initialized instance
    148  *
    149  * Return value         :  0 - Ok
    150  *                        -1 - Error
    151  */
    152 int WebRtcNs_set_policy_core(NoiseSuppressionC* self, int mode);
    153 
    154 /****************************************************************************
    155  * WebRtcNs_AnalyzeCore
    156  *
    157  * Estimate the background noise.
    158  *
    159  * Input:
    160  *      - self          : Instance that should be initialized
    161  *      - speechFrame   : Input speech frame for lower band
    162  *
    163  * Output:
    164  *      - self          : Updated instance
    165  */
    166 void WebRtcNs_AnalyzeCore(NoiseSuppressionC* self, const float* speechFrame);
    167 
    168 /****************************************************************************
    169  * WebRtcNs_ProcessCore
    170  *
    171  * Do noise suppression.
    172  *
    173  * Input:
    174  *      - self          : Instance that should be initialized
    175  *      - inFrame       : Input speech frame for each band
    176  *      - num_bands     : Number of bands
    177  *
    178  * Output:
    179  *      - self          : Updated instance
    180  *      - outFrame      : Output speech frame for each band
    181  */
    182 void WebRtcNs_ProcessCore(NoiseSuppressionC* self,
    183                           const float* const* inFrame,
    184                           size_t num_bands,
    185                           float* const* outFrame);
    186 
    187 #ifdef __cplusplus
    188 }
    189 #endif
    190 #endif  // WEBRTC_MODULES_AUDIO_PROCESSING_NS_NS_CORE_H_
    191