MFCC提取的C语言实现与详解

设计mel域三角滤波器那一块没有看懂，有高手看懂了，指点一下。。。

mfcc.h
// Cepstrum
#define FE_CEP_ORDER           12 /* Number of cepstral coefficients is CEPORDER+1 including c0 */

// Dynamic features
#define FE_DELTA                5 /* Order of delta coefficients */
#define FE_DDELTA               3 /* Order of acceleration (delta-delta) coefficients */

// Filter bank
#define FE_NUM_CHANNELS        23 /* Number of bands in filter bank */
#define FE_FBANK_FLOOR    (-50.0) /* Energy floor for filter bank coefficients */
#define FE_MIN_ENERGY (1)
#define FE_MIN_LOG_ENERGY (0)
#define M_PI   3.14159265358979323846
#define NR_NUM_CHANNELS             23
#define NR_FL                       17

typedef struct { /* mel filter banks */
    int m_lowX;
    int m_centerX;
    int m_highX;
} MfccMelFB;

typedef struct {
    int m_lowX;
    int m_centerX;
    int m_highX;
float m_sumWeight;

} WfMelFB; /* mel filter bank for noise reduction */


int preemphasize(float *sample, int sampleN);
int preprocessing(short *sample, int sampleN, float *out);
int Do_hamm_window(float *inputA, int inputN);
int mel_cepstrum_basic(short *sample, int frameSize, float *mel_cep, int ceporder, int fft_size);
int MfccInitDCTMatrix (float *dctMatrix, int ceporder, int numChannels);
int _mel_cepstrum_basic(float *sample, int frameSize, float *mel_cep, int fborder, int ceporder, int fft_size);
void MfccInitMelFilterBanks (float startingFrequency, float samplingRate, int fftLength, int numChannels);
float LogE(float x);
void PRFFT_NEW(float *a, float *b, int m, int n_pts, int iff);
void MfccMelFilterBank (float *sigFFT, int numChannels, float* output, int normalize);
int _filterbank_basic(float *sample, int frameSize, float *filter_bank, int fborder, int fftSize, int cep_smooth, int cepFilterLen);
void MfccDCT (float *x, float *dctMatrix, int ceporder, int numChannels, float *mel_cep);



mfcc.c

#include "mfcc.h"
#include <math.h>
#include <stdio.h>

int m_cepOrder = 12;
int m_fbOrder = 23;
float m_dctMatrix[(12+1)*23];
int m_sampleRate=32000;
WfMelFB m_MelFB[23];
float m_MelWeight[512/2+1];