phi_xits.h

MPEG2/MPEG4编解码参考程序(实现了MPEG4的部分功能)

/*====================================================================*/
/*         MPEG-4 Audio (ISO/IEC 14496-3) Copyright Header            */
/*====================================================================*/
/*
This software module was originally developed by Rakesh Taori and Andy
Gerrits (Philips Research Laboratories, Eindhoven, The Netherlands) in
the course of development of the MPEG-4 Audio (ISO/IEC 14496-3). This
software module is an implementation of a part of one or more MPEG-4
Audio (ISO/IEC 14496-3) tools as specified by the MPEG-4 Audio
(ISO/IEC 14496-3). ISO/IEC gives users of the MPEG-4 Audio (ISO/IEC
14496-3) free license to this software module or modifications thereof
for use in hardware or software products claiming conformance to the
MPEG-4 Audio (ISO/IEC 14496-3). Those intending to use this software
module in hardware or software products are advised that its use may
infringe existing patents. The original developer of this software
module and his/her company, the subsequent editors and their
companies, and ISO/IEC have no liability for use of this software
module or modifications thereof in an implementation. Copyright is not
released for non MPEG-4 Audio (ISO/IEC 14496-3) conforming products.
CN1 retains full right to use the code for his/her own purpose, assign
or donate the code to a third party and to inhibit third parties from
using the code for non MPEG-4 Audio (ISO/IEC 14496-3) conforming
products.  This copyright notice must be included in all copies or
derivative works. Copyright 1996.
*/
/*====================================================================*/
/*======================================================================*/
/*                                                                      */
/*      INCLUDE_FILE:   PHI_XITS.H                                      */
/*      PACKAGE:        WDBxx                                           */
/*      COMPONENT:      Subroutines for Excitation Modules              */
/*                                                                      */
/*======================================================================*/

#ifndef _phi_xits_h_
#define _phi_xits_h_

#ifdef __cplusplus
extern "C" {
#endif

/*======================================================================*/
/* Function Prototype: perceptual_weighting                             */
/*======================================================================*/
void 
PHI_perceptual_weighting
(
long  nos,              /* In:     Number of samples to be processed    */
float *vi,              /* In:     Array of input samps to be processe  */
float *vo,              /* Out:    Perceptually Weighted Output Speech  */ 
long  order,            /* In:     LPC-Order of the weighting filter    */ 
float *a_gamma,         /* In:     Array of the Weighting filter coeffs */
float *vp1              /* In/Out: The delay line states                */
);

/*
------------------------------------------------------------------------
  zero input response 
------------------------------------------------------------------------
*/

void 
PHI_calc_zero_input_response
(
long  nos,               /* In:     Number of samples to be processed   */
float *vo,               /* Out:    The zero-input response             */ 
long  order,             /* In:     Order of the Weighting filter       */
float *a_gamma,          /* In:     Coefficients of the weighting filter*/
float *vp                /* In:     Filter states                       */
);

/*
----------------------------------------------------------------------------
  weighted target signal
----------------------------------------------------------------------------
*/

void 
PHI_calc_weighted_target
(
long nos,               /* In:     Number of samples to be processed    */
float *v1,              /* In:     Array of Perceptually weighted speech*/ 
float *v2,              /* In:     The zero-input response              */ 
float *vd               /* Out:    Real Target signal for current frame */
);

/*
----------------------------------------------------------------------------
  impulse response
----------------------------------------------------------------------------
*/

void 
PHI_calc_impulse_response
(
long  nos,              /* In:     Number of samples to be processed    */
float *h,               /* Out:    Impulse response of the filter       */
long  order,            /* In:     Order of the filter                  */ 
float *a_gamma          /* In:     Array of the filter coefficients     */
);

/*
------------------------------------------------------------------------
  backward filtering 
------------------------------------------------------------------------
*/

void 
PHI_backward_filtering
(
long  nos,              /* In:     Number of samples to be processed    */
float *vi,              /* In:     Array of samples to be filtered      */ 
float *vo,              /* Out:    Array of filtered samples            */ 
float *h                /* In:     The filter coefficients              */
);

/*
----------------------------------------------------------------------------
  adaptive codebook search
----------------------------------------------------------------------------
*/

void 
PHI_cba_search
(
long   nos,             /* In:     Number of samples to be processed    */
long   max_lag,         /* In:     Maximum Permitted Adapt cbk Lag      */
long   min_lag,         /* In:     Minimum Permitted Adapt cbk Lag      */
float  *cb,             /* In:     Segment of Adaptive Codebook         */
long   *pi,             /* In:     Array of preselected-lag indices     */
long   n_lags,          /* In:     Number of lag candidates to be tried */
float  *h,              /* In:     Impulse response of synthesis filter */ 
float  *t,              /* In:     The real target signal               */ 
float  *g,              /* Out:    Adapt-cbk gain(Quantised but uncoded)*/
long   *vid,            /* Out:    The final adaptive cbk lag index     */ 
long   *gid             /* Out:    The gain index                       */
);

/*
----------------------------------------------------------------------------
  computes residual signal after adaptive codebook
----------------------------------------------------------------------------
*/
    
void 
PHI_calc_cba_residual
(
long  nos,             /* In:     Number of samples to be processed    */
float *vi,             /* In:     Succesful excitation candidate       */ 
float gain,            /* In:     Gain of the adaptive codebook        */ 
float *h,              /* In:     Impulse response of synthesis filt   */
float *t,              /* In:     The real target signal               */
float *e               /* Out:    Adapt-cbk residual: Target for f-cbk */
);

/*
----------------------------------------------------------------------------
  determines phase of the local rpe codebook vectors
----------------------------------------------------------------------------
*/

void 
PHI_calc_cbf_phase
(
long  pulse_spacing,    /* In:    Regular Spacing Between Pulses        */
long  nos,              /* In:    Number of samples to be processed     */
float *tf,              /* In:    Backward filtered target signal       */ 
long  *p                /* Out:   Phase of the local RPE codebook vector*/
);

/*
----------------------------------------------------------------------------
  computes rpe pulse amplitude (Version 2:only computes amplitude)
----------------------------------------------------------------------------
*/

void 
PHI_CompAmpArray
(
long  num_of_pulses,    /* In:    Number of pulses in the sequence      */
long  pulse_spacing,    /* In:    Regular Spacing Between Pulses        */
float *tf,              /* In:    Backward filtered target signal       */ 
long  p,                /* In:    Phase of the RPE codebook             */
long  *amp             /* Out:   Pulse amplitudes  +/- 1               */ 
);


/*
----------------------------------------------------------------------------
  computes pos array {extension to Vienna code which only fixed 1 amp
----------------------------------------------------------------------------
*/

void 
PHI_CompPosArray
(
long  num_of_pulses,    /* In:    Number of pulses in the sequence      */
long  pulse_spacing,    /* In:    Regular Spacing Between Pulses        */
long  num_fxd_amps,     /* IN:    Number of fixed amplitudes            */
float *tf,              /* In:    Backward filtered target signal       */ 
long  p,                /* In:    Phase of the RPE codebook             */
long  *pos              /* Out:   Pulse amplitudes  +/- 1               */ 
);

/*
----------------------------------------------------------------------------
  generates local fixed codebook
----------------------------------------------------------------------------
*/

void 
PHI_generate_cbf
(