ld8a.h

关于对传统的只能传递文本信息的G。729的改进

/*
   ITU-T G.729 Annex C - Reference C code for floating point
                         implementation of G.729 Annex A
                         Version 1.01 of 15.September.98
*/

/*
----------------------------------------------------------------------
                    COPYRIGHT NOTICE
----------------------------------------------------------------------
   ITU-T G.729 Annex C ANSI C source code
   Copyright (C) 1998, AT&T, France Telecom, NTT, University of
   Sherbrooke.  All rights reserved.

----------------------------------------------------------------------
*/


/*-----------------------------------------------------------*
 * ld8a.h - include file for G.729a 8.0 kb/s codec           *
 *-----------------------------------------------------------*/

#include <stdio.h>
#include <stdlib.h>

#ifdef PI
#undef PI
#endif
#ifdef PI2
#undef PI2
#endif
#define PI              (F)3.141592654
#define PI2             (F)6.283185307
#define FLT_MAX_G729    (F)1.0e38    /* largest floating point number      */
#define FLT_MIN_G729    (F)-1.0e38   /* largest floating point number      */

/*--------------------------------------------------------------------------*
 *       Codec constant parameters (coder, decoder, and postfilter)         *
 *--------------------------------------------------------------------------*/

#define L_TOTAL         240     /* Total size of speech buffer              */
#define L_WINDOW        240     /* LPC analysis window size                 */
#define L_NEXT          40      /* Samples of next frame needed for LPC ana.*/
#define L_FRAME         80      /* LPC update frame size                    */
#define L_SUBFR         40      /* Sub-frame size                           */

#define PIT_MIN         20      /* Minimum pitch lag in samples             */
#define PIT_MAX         143     /* Maximum pitch lag in samples             */
#define L_INTERPOL      (10+1)  /* Length of filter for interpolation.      */
#define GAMMA1       (F)0.75    /* Bandwitdh expansion for W(z)             */


/*--------------------------------------------------------------------------*
 * constants for lpc analysis and lsp quantizer                             *
 *--------------------------------------------------------------------------*/

#define M               10      /* LPC order                                */
#define MP1             (M+1)   /* LPC order+1                              */
#define NC              (M/2)   /* LPC order / 2                            */
#define WNC          (F)1.0001  /* white noise correction factor            */
#define GRID_POINTS      50     /* resolution of lsp search                 */

#define MA_NP           4       /* MA prediction order for LSP              */
#define MODE            2       /* number of modes for MA prediction        */
#define NC0_B           7       /* number of bits in first stage            */
#define NC0          (1<<NC0_B) /* number of entries in first stage         */
#define NC1_B           5       /* number of bits in second stage           */
#define NC1          (1<<NC1_B) /* number of entries in second stage        */

#define L_LIMIT         (F)0.005   /*  */
#define M_LIMIT         (F)3.135   /*  */
#define GAP1            (F)0.0012  /*  */
#define GAP2            (F)0.0006  /*  */
#define GAP3            (F)0.0392  /*  */
#define PI04            PI*(F)0.04   /* pi*0.04 */
#define PI92            PI*(F)0.92   /* pi*0.92 */
#define CONST12         (F)1.2

/*------------------------------------------------------------------*
 *  Constants for long-term predictor                               *
 *------------------------------------------------------------------*/

#define  SHARPMAX       (F)0.7945  /* Maximum value of pitch sharpening */
#define  SHARPMIN       (F)0.2     /* Minimum value of pitch sharpening */
#define  GAIN_PIT_MAX   (F)1.2     /* Maximum adaptive codebook gain    */

#define  UP_SAMP         3         /* Resolution of fractional delays   */
#define  L_INTER10       10        /* Length for pitch interpolation    */
#define  FIR_SIZE_SYN    (UP_SAMP*L_INTER10+1)

/*-----------------------*
 * Innovative codebook.  *
 *-----------------------*/

#define DIM_RR  616 /* size of correlation matrix                            */
#define NB_POS  8   /* Number of positions for each pulse                    */
#define STEP    5   /* Step betweem position of the same pulse.              */
#define MSIZE   64  /* Size of vectors for cross-correlation between 2 pulses*/

/*------------------------------------------------------------------*
 *  gain quantizer                                                  *
 *------------------------------------------------------------------*/

#define MEAN_ENER     (F)36.0   /* Average innovation energy */
#define NCODE1           8      /* Codebook 1 size */
#define NCODE2           16     /* Codebook 2 size */
#define NCAN1            4      /* Pre-selecting order for #1 */
#define NCAN2            8      /* Pre-selecting order for #2 */
#define INV_COEF      (F)-0.032623

/*------------------------------------------------------------------*
 *  Constant for postfilter                                         *
 *------------------------------------------------------------------*/

#define  GAMMA2_PST  (F)0.55       /* Formant postfilt factor (numerator)   */
#define  GAMMA1_PST  (F)0.70       /* Formant postfilt factor (denominator) */
#define  GAMMAP      (F)0.50       /* Harmonic postfilt factor              */
#define  INV_GAMMAP  ((F)1.0/((F)1.0+GAMMAP))
#define  GAMMAP_2    (GAMMAP/((F)1.0+GAMMAP))

#define  MU          (F)0.8        /* Factor for tilt compensation filter   */
#define  AGC_FAC     (F)0.9        /* Factor for automatic gain control     */
#define  AGC_FAC1     ((F)1.-AGC_FAC)
#define  L_H 22   /* size of truncated impulse response of A(z/g1)/A(z/g2) */

/*--------------------------------------------------------------------------*
 * Constants for taming procedure.                           *
 *--------------------------------------------------------------------------*/

#define GPCLIP      (F)0.95     /* Maximum pitch gain if taming is needed */
#define GPCLIP2     (F)0.94     /* Maximum pitch gain if taming is needed */
#define GP0999      (F)0.9999   /* Maximum pitch gain if taming is needed    */
#define THRESH_ERR  (F)60000.   /* Error threshold taming    */
#define INV_L_SUBFR (FLOAT) ((F)1./(FLOAT)L_SUBFR) /* =0.025 */

/*-----------------------*
 * Bitstream constants   *
 *-----------------------*/

#define BIT_0     (short)0x007f /* definition of zero-bit in bit-stream     */
#define BIT_1     (short)0x0081 /* definition of one-bit in bit-stream      */
#define SYNC_WORD (short)0x6b21 /* definition of frame erasure flag         */
#define PRM_SIZE        11      /* number of parameters per 10 ms frame     */
#define SERIAL_SIZE     82      /* bits per frame                           */
#define SIZE_WORD (short)80     /* number of speech bits                     */

/*-------------------------------*
 * Pre and post-process functions*
 *-------------------------------*/
void init_post_process( void
);

void post_process(
   FLOAT signal[],      /* (i/o)  : signal           */
   int lg               /* (i)    : lenght of signal */
);

void init_pre_process( void
);

void pre_process(
   FLOAT signal[],      /* (i/o)  : signal           */
   int lg               /* (i)    : lenght of signal */
);

/*----------------------------------*
 * Main coder and decoder functions *
 *----------------------------------*/
void  init_coder_ld8a(void);

void  coder_ld8a(
 int ana[]              /* output: analysis parameters */
);

void  init_decod_ld8a(void);

void  decod_ld8a(
  int parm[],          /* (i)   : vector of synthesis parameters
                                  parm[0] = bad frame indicator (bfi)  */
  FLOAT   synth[],     /* (o)   : synthesis speech                     */
  FLOAT   A_t[],       /* (o)   : decoded LP filter in 2 subframes     */
  int *T2,              /* (o)   : decoded pitch lag in 2 subframes     */
  int     bfi           /* (i)   :bad frame indicator (bfi)      */
);

/*-------------------------------*
 * LPC analysis and filtering.   *
 *-------------------------------*/
void  autocorr(FLOAT *x, int m, FLOAT *r);

void  lag_window(int m, FLOAT r[]);

FLOAT levinson(FLOAT *a, FLOAT *r, FLOAT *r_c);

void  az_lsp(FLOAT *a, FLOAT *lsp, FLOAT *old_lsp);

void  int_qlpc(FLOAT lsp_new[], FLOAT lsp_old[], FLOAT a[]);

void  weight_az(FLOAT *a,  FLOAT gamma, int m,  FLOAT *ap);

void residu(    /* filter A(z)                                       */
 FLOAT *a,      /* input : prediction coefficients a[0:m+1], a[0]=1. */
 FLOAT *x,      /* input : input signal x[0:l-1], x[-1:m] are needed */
 FLOAT *y,      /* output: output signal y[0:l-1] NOTE: x[] and y[]
                            cannot point to same array               */
 int l          /* input : dimension of x and y                      */
);

void syn_filt(
 FLOAT a[],     /* input : predictor coefficients a[0:m]    */
 FLOAT x[],     /* input : excitation signal                */
 FLOAT y[],     /* output: filtered output signal           */
 int l,         /* input : vector dimension                 */