www.pudn.com > ETSI_ES_202_212_software.rar > CompCeps.c
/*===============================================================================
* ETSI ES 202 212 Distributed Speech Recognition
* Extended Advanced Front-End Feature Extraction Algorithm & Compression Algorithm
* Speech Reconstruction Algorithm.
* C-language software implementation
* Version 1.1.1 October, 2003
*===============================================================================*/
/*-------------------------------------------------------------------------------
*
* FILE NAME: CompCeps.c
* PURPOSE: Calculating cepstral features and logE for the de-noised
* input frame.
*
*-------------------------------------------------------------------------------*/
/*-----------------
* File Inclusions
*-----------------*/
#include
#include
#include
#include
#include "ParmInterface.h"
#include "CompCepsExports.h"
#include "16kHzProcExports.h"
#include "MelProcExports.h"
#include "rfft.h"
/*----------------------
* Constant Definitions
*----------------------*/
#define PI 3.14159265358979323846
#define PIx2 6.28318530717958647692
/*-------------------------------
* Global Definitions and Macros
*-------------------------------*/
#define CC_NUM_CHANNELS_WI8 23
#define CC_PRE_EMPHASIS 0.90
#define CC_ENERGYFLOOR_FB -10.0
#define CC_ENERGYFLOOR_logE -50.0
#define CC_FRAME_LENGTH 200
#define CC_FFT_LENGTH 256
#define CC_FFT_LENGTH_ORDER 8
struct CompCepsStructX
{
X_INT16 SamplingFrequency; //
X_FLOAT32 StartingFrequency; //
X_FLOAT32 HammingWindow [CC_FRAME_LENGTH]; //
X_FLOAT32 *pDCTMatrix; //
MelFB_Window *FirstWindow; //
BOOLEAN Noc0; //
BOOLEAN Do16kHzProc; //
DataFor16kProc *pData16k; //
};
/*------------
* Prototypes
*------------*/
static void WI8CompCeps (CompCepsStructX *CCX, X_FLOAT32 *curFrameFloatBuf,
X_FLOAT32 *cepOut, DataFor16kProc *pData16k);
static void InitializeHamming (X_FLOAT32 *win, X_INT16 len);
static void Window (X_FLOAT32 *data, X_FLOAT32 *win, X_INT16 len);
static void DCT (X_FLOAT32 *Data, X_FLOAT32 *Mx, X_INT16 NumCepstralCoeff, X_INT16 NumChannels);
static X_FLOAT32 *InitDCTMatrix (X_INT16 NumCepstralCoeff, X_INT16 NumChannels);
/*-----------
* Functions
*-----------*/
/*---------------------------------------------------------------------------
* FUNCTION NAME: InitializeHamming
*
* PURPOSE: Initializes Hamming window coefficients
*
* INPUT:
* win Pointer to window buffer
* len Window length
*
* OUTPUT
* Hamming window coefficients stored in window buffer pointed
* to by *win*
*
* RETURN VALUE
* none
*
*---------------------------------------------------------------------------*/
static void InitializeHamming (X_FLOAT32 *win, X_INT16 len)
{
X_INT16 i;
for (i=0 ; iCCX;
//16kHz processing
CCX->Do16kHzProc = This->Do16kHzProc;
CCX->pData16k = This->pData16k;
if (CCX->Do16kHzProc)
CCX->pDCTMatrix = InitDCTMatrix (NUM_CEP_COEFF, CC_NUM_CHANNELS_WI8 + HP16k_MEL_USED);
else
CCX->pDCTMatrix = InitDCTMatrix (NUM_CEP_COEFF, CC_NUM_CHANNELS_WI8);
CCX->Noc0 = This->Noc0;
CCX->SamplingFrequency = This->SamplingFrequency;
CCX->StartingFrequency = This->StartingFrequency;
CCX->FirstWindow = CMelFBAlloc ();
InitFFTWindows (CCX->FirstWindow, CCX->StartingFrequency,
CCX->SamplingFrequency, CC_FFT_LENGTH, CC_NUM_CHANNELS_WI8);
ComputeTriangle (CCX->FirstWindow);
InitializeHamming (CCX->HammingWindow, CC_FRAME_LENGTH);
}
/*----------------------------------------------------------------------------
* FUNCTION NAME: DoCompCeps
*
* PURPOSE: Cepstral computation for a frame
*
*
* INPUT:the current frame
*
*
* OUTPUT:NUM_CEP_COEFF + 1 coefficients (including c0) + LogEnergy
*
*
* RETURN VALUE:TRUE (a frame is always output)
*
* WARNING !!! : The preceeding sample (index=-1) must be present in Data
*---------------------------------------------------------------------------*/
extern BOOLEAN DoCompCeps (X_FLOAT32 *Data, X_FLOAT32 *Coef, FEParamsX *This)
{
CompCepsStructX *CCX = This->CCX;
DataFor16kProc *pData16k = This->pData16k;
WI8CompCeps (CCX, Data, Coef, pData16k);
return TRUE;
}
/*----------------------------------------------------------------------------
* FUNCTION NAME: DoCompCepsDelete
*
* PURPOSE:
*
*
* INPUT:
*
*
* OUTPUT:
*
*
* RETURN VALUE:
*
*
*---------------------------------------------------------------------------*/
extern void DoCompCepsDelete (CompCepsStructX *CCX)
{
if (CCX != NULL)
{
ReleaseMelFBwindows (CCX->FirstWindow);
free (CCX);
}
return;
}
/*----------------------------------------------------------------------------
* FUNCTION NAME: DoCompCepsDelete
*
* PURPOSE:
*
*
* INPUT:
*
*
* OUTPUT:
*
*
* RETURN VALUE:
*
*
*---------------------------------------------------------------------------*/
void WI8CompCeps (CompCepsStructX *CCX, X_FLOAT32 *curBuffer, X_FLOAT32 *cepOut, DataFor16kProc *pData16k)
{
X_FLOAT32 LogEnergy;
X_FLOAT32 EnergyFloor_FB;
X_FLOAT32 EnergyFloor_logE;
X_FLOAT32 *FloatBuffer;
X_INT16 i;
/*-------------------
* 16 kHz processing
*-------------------*/
X_INT16 hp16kBandsSize;
X_FLOAT32 hp16kBands [HP16k_MEL_USED];
X_FLOAT32 *codeWeights;
X_FLOAT32 *CodeForBands16k;
X_FLOAT32 percCoded;
FloatBuffer = (X_FLOAT32 *) malloc (sizeof (X_FLOAT32) * CC_FFT_LENGTH);
if (FloatBuffer == NULL)
{
fprintf (stderr, "ERROR: Memory allocation error occured!\r\n");
exit(0);
}
if (CCX->Do16kHzProc)
{
hp16kBandsSize = HP16k_MEL_USED;
codeWeights = Get16k_p_bufferCodeWeights (CCX->pData16k);
CodeForBands16k = Get16k_p_bufferCodeForBands16k (CCX->pData16k);
percCoded = Get16k_percCoded (CCX->pData16k);
}
else
{
hp16kBandsSize = 0;
codeWeights = NULL;
CodeForBands16k = NULL;
percCoded = 0.0;
}
/*----------------
* Initialization
*----------------*/
EnergyFloor_FB = (X_FLOAT32) exp ((double) CC_ENERGYFLOOR_FB);
EnergyFloor_logE = (X_FLOAT32) exp ((double) CC_ENERGYFLOOR_logE);
/*------------------
* logE computation
*------------------*/
LogEnergy = 0.0;
for (i=0 ; iDo16kHzProc)
{
if (LogEnergy < EnergyFloor_logE)
LogEnergy = CC_ENERGYFLOOR_logE;
else
LogEnergy = (X_FLOAT32) log ((double)LogEnergy);
}
/*-------------------------------------------------
* Pre-emphasis, notice that curBuffer[-1] is used
*-------------------------------------------------*/
for (i=0 ; iHammingWindow, CC_FRAME_LENGTH);
/*--------------
* Zero padding
*--------------*/
for (i=CC_FRAME_LENGTH ; iDo16kHzProc)
{
X_FLOAT32 aux [3];
GetBandsForDecoding16k (FloatBuffer, aux, CC_FFT_LENGTH/2+1);
for (i=0 ; i<3 ; i++)
{
if (aux [i] > EnergyFloor_FB)
aux [i] = (X_FLOAT32) log ((double) aux [i]);
else
aux [i] = CC_ENERGYFLOOR_FB;
}
// temporarily
codeWeights [0] = 0.1; codeWeights [1] = 0.2; codeWeights [2] = 0.7;
DecodeBands16k (hp16kBands, aux, CodeForBands16k, codeWeights);
}
/*---------------
* Mel filtering
*---------------*/
DoMelFB (FloatBuffer, CCX->FirstWindow);
/*-------------------
* 16 kHz processing
*-------------------*/
if (CCX->Do16kHzProc)
{
X_FLOAT32 preemphs_correction = log (1.0 + CC_PRE_EMPHASIS);
X_FLOAT32 *hpBands;
hpBands = Get16k_p_hpBands (pData16k);
/*-----------------------------------------------------------
* SS HP bands -> including and rough preemphasis correction
*-----------------------------------------------------------*/
for (i=CC_NUM_CHANNELS_WI8 ; i rough preemphasis correction
*------------------------------------------------*/
for (i=0 ; iDo16kHzProc)
{
/*--------------------------------------------
* mixing coded and SS HP bands in log domain
*--------------------------------------------*/
MergeSSandCoded (FloatBuffer, hp16kBands, CC_NUM_CHANNELS_WI8, &hp16kBandsSize, CCX->pData16k);
LogEnergy = CorrectEnergy (LogEnergy, hp16kBandsSize, FloatBuffer, CC_NUM_CHANNELS_WI8, CC_PRE_EMPHASIS);
if (LogEnergy < EnergyFloor_logE)
LogEnergy = CC_ENERGYFLOOR_logE;
else
LogEnergy = (X_FLOAT32) log ((double) LogEnergy);
}
/*---------------------------
* Discrete Cosine Transform
*---------------------------*/
DCT (FloatBuffer, CCX->pDCTMatrix, NUM_CEP_COEFF, CC_NUM_CHANNELS_WI8 + hp16kBandsSize);
/*--------------------------------------
* Append logE after c0 or overwrite c0
*--------------------------------------*/
FloatBuffer[CC_NUM_CHANNELS_WI8 + hp16kBandsSize + NUM_CEP_COEFF - (CCX->Noc0 ? 1:0)] = LogEnergy;
for (i=0 ; i