intanaly.c

this the source code of addio compression standard CELP. Also, it is optimizied for the execution sp

/**************************************************************************
*
* ROUTINE
*		intanaly
*
* FUNCTION
*		Linearly interpolate between transmitted LSPs
*		to generate nn (=4) intermediate sets of LSP
*		frequencies for subframe analysis. 
*		
*
* SYNOPSIS
*		subroutine intanaly(lspnew, nn, lsp)
*
*   formal 
*
*                       data    I/O
*       name            type    type    function
*       -------------------------------------------------------------------
*	lspnew		float	i	new frequency array
*	nn		int	i	number of segments/frame
*	lsp		float	o	interpolated frequency matrix
*
*   external 
*                       data    I/O
*       name            type    type    function
*       -------------------------------------------------------------------
*	no		int	i
*	frame		int	i
*
***************************************************************************
*
* DESCRIPTION
*		This routine linearly interpolates lsp's for analysis in
*	nn (=4) subframes.  This is a combination of inter- and 
*	intra-frame interpolation.  There are two routines, one for the 
*	analyzer and one for the synthesizer.
*
*		The lsps are interpolated from two transmitted frames,
*	 old and new.  The lsp interpolation is calculated as follows:
*
*	superframe:       old	    	       new
*
*		|	      	      |      		    |
*		|---------------------|---------------------|
*		|	      	      |      		    |
*
*	         \		                           /
*                 \                                       /
*
*	subframe:         1       2        3        4
*		     |			       	         |
*	       ...---|--------|--------|--------|--------|
*		     |			                 |
*			  v       v        v        v
*
*	weighting:
*		old:     7/8      5/8      3/8      1/8
*		new:     1/8      3/8      5/8      7/8
*
*	Note: This is dependent on nn = ll/l = 4!
*	
***************************************************************************
*
* CALLED BY
*
*	celp
*
* CALLS
*
*
*
**************************************************************************/
#define TRUE	1
#define FALSE	0
#include "ccsub.h"
extern int no, frame;
static float tempfreq, w[2][4] =   { 0.875, 0.625, 0.375, 0.125,  
                                     0.125, 0.375, 0.625, 0.875};
intanaly(lspnew, nn, lsp)
int nn;
float lspnew[];
register float lsp[][MAXNO];
{
register  int m;
  static float lspold[MAXNO] = {.03, .05, .09, .13, .19,                                           .23, .29, .33, .39, .44};
  static float oldlsp[MAXNO];

#define STEP(i,j)     lsp[i][j] = w[0][i]*lspold[j] + w[1][i]*lspnew[j];

    STEP(0,0); STEP(0,1); STEP(0,2); STEP(0,3); STEP(0,4);
    STEP(0,5); STEP(0,6); STEP(0,7); STEP(0,8); STEP(0,9);
    STEP(1,0); STEP(1,1); STEP(1,2); STEP(1,3); STEP(1,4);
    STEP(1,5); STEP(1,6); STEP(1,7); STEP(1,8); STEP(1,9);
    STEP(2,0); STEP(2,1); STEP(2,2); STEP(2,3); STEP(2,4);
    STEP(2,5); STEP(2,6); STEP(2,7); STEP(2,8); STEP(2,9);
    STEP(3,0); STEP(3,1); STEP(3,2); STEP(3,3); STEP(3,4);
    STEP(3,5); STEP(3,6); STEP(3,7); STEP(3,8); STEP(3,9);
/*
  for (i = 0; i < nn; i++)
  {
    for (j = 0; j < no; j++)
      lsp[i][j] = w[0][i]*lspold[j] + w[1][i]*lspnew[j];
  }
*/  

  for (m = 0; m < no; m++)
  {
    lspold[m] = lspnew[m];
    oldlsp[m] = lsp[nn][m];
  }
}