csub.c

语音CELP压缩解压源代码（C语音)

/**************************************************************************
*
* ROUTINE
*               csub
*
* FUNCTION
*               control routine to find optimal excitation 
*		(adaptive and stochastic code book searches)
*
* SYNOPSIS
*               subroutine csub(s, v, l, lp)
*
*   formal
*
*                       data    I/O
*       name            type    type    function
*       -------------------------------------------------------------------
*       s[l]            float	i       speech or residual segment
*       v[l]            float	o       optimum excitation vector
*       l               int	i       stochastic analysis frame size
*	lp		int	i	adaptive (pitch) analysis frame size
*
*   external
*                       data    I/O
*       name            type    type    function
*       -------------------------------------------------------------------
*	idb		int	i
*	no		int	i
*	nseg		int	i
*	sg		int	i
*	e0[]		float	i/o
*	fndex_e0_vid	int	i
*	fndpp_e0_vid	int	i
*	mxsw		int	i	modified excitation switch
*	
***************************************************************************
*
*  Global
*
*	SPECTRUM VARIABLES:
*	d2a	real	memory 1/A(z)
*	d2b	real	memory 1/A(z)
*	d3a	real	memory A(z)
*	d3b	real	memory A(z)
*	d4a	real	memory 1/A(z/gamma)
*	d4b	real	memory 1/A(z/gamma)
*
*	PITCH VARIABLES:
*	d1a	real	memory 1/P(z)
*	d1b	real	memory 1/P(z)
***************************************************************************
*
* CALLED BY
*
*       celp
*
* CALLS
*
*       confg   cbsearch   psearch   movefr   save_sg   setr
*
*	mescite1   mexcite2
*
**************************************************************************/
#include "ccsub.h"
float d1a[MAXPA], d1b[MAXPA], d2a[MAXNO+1], d2b[MAXNO+1], d3a[MAXNO+1], d3b[MAXNO+1];
float d4a[MAXNO+1], d4b[MAXNO+1];
extern int idb, no, nseg, sg, mxsw;
extern float e0[MAXLP];

#ifdef SUNGRAPH
extern int fndex_e0_vid, fndpp_e0_vid;

#endif

csub(s, v, l, lp)
int l, lp;
float s[], v[];

{

  /* *find the intial error without pitch VQ		 	 */

  setr(l, 0.0, e0);
  confg(s, l, d1a, d2a, d3a, d4a, 0, 1, 1, 1);
  movefr(no + 1, d2b, d2a);
  movefr(no + 1, d3b, d3a);
  movefr(no + 1, d4b, d4a);

  /* *find impulse response (h) of perceptual weighting filter	 */

  impulse(l);

  /* *norm of the first error signal for const. exc.		 */

  if (mxsw) 
    mexcite1(l);

  /* *pitch (adaptive code book) search						 */

  /* Get pp parameters every segment if lp = l. If lp <> l then	 */
  /* get pp parameters on odd segments. 			 */

  if (lp == l)
    psearch(l);
  else if (nseg % 2 == 1)
    psearch(lp);

#ifdef SUNGRAPH
    save_sg(fndpp_e0_vid, e0, l, "save fndpp_e0_vid");
#endif

  /* *find initial error with pitch VQ				 */

  setr(l, 0.0, e0);
  confg(s, l, d1a, d2a, d3a, d4a, 1, 1, 1, 1);

#ifdef SUNGRAPH
    save_sg(fndex_e0_vid, e0, l, "save fndex_e0_vid");
#endif


  /* *norm of second error signal for const. exc.		 */

  if (mxsw)
    mexcite2(l);

  /* *stochastic code book search 				 */

  cbsearch(l, v);

  /* *update filter states 					 */

  movefr(l, v, e0);
  confg(s, l, d1b, d2b, d3b, d4b, 1, 1, 1, 1);
  movefr(idb, d1b, d1a);
  movefr(no + 1, d2b, d2a);
  movefr(no + 1, d3b, d3a);
  movefr(no + 1, d4b, d4a);
}