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    /*
    
    $Log$
    
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    Revision 1.7  2000/01/05 08:20:40  markster
    Version 0.1.8 from FTP
    
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    Revision 1.2  2000/01/05 08:20:40  markster
    Some OSS fixes and a few lpc changes to make it actually work
    
     * Revision 1.1  1996/08/19  22:30:26  jaf
     * Initial revision
     *
    
    */
    
    #ifdef P_R_O_T_O_T_Y_P_E_S
    extern int tbdm_(real *speech, integer *lpita, integer *tau, integer *ltau, real *amdf, integer *minptr, integer *maxptr, integer *mintau);
    /*:ref: difmag_ 14 8 6 4 4 4 4 6 4 4 */
    #endif
    
    /*  -- translated by f2c (version 19951025).
       You must link the resulting object file with the libraries:
    	-lf2c -lm   (in that order)
    */
    
    #include "f2c.h"
    
    /* ********************************************************************** */
    
    /* 	TBDM Version 49 */
    
    /* $Log$
    
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     * Revision 1.7  2000/01/05 08:20:40  markster
     * Version 0.1.8 from FTP
    
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     *
    /* Revision 1.2  2000/01/05 08:20:40  markster
    /* Some OSS fixes and a few lpc changes to make it actually work
    /*
     * Revision 1.1  1996/08/19  22:30:26  jaf
     * Initial revision
     * */
    /* Revision 1.3  1996/03/18  22:14:00  jaf */
    /* Just added a few comments about which array indices of the arguments */
    /* are used, and mentioning that this subroutine has no local state. */
    
    /* Revision 1.2  1996/03/13  14:48:37  jaf */
    /* Comments added explaining that none of the local variables of this */
    /* subroutine need to be saved from one invocation to the next. */
    
    /* Revision 1.1  1996/02/07 14:49:54  jaf */
    /* Initial revision */
    
    
    /* ********************************************************************* */
    
    /*TURBO DIFMAG: Compute High Resolution Average Magnitude Difference Function
    */
    
    /* Note: There are several constants in here that appear to depend on a */
    /* particular TAU table.  That's not a problem for the LPC10 coder, but */
    /* watch out if you change the contents of TAU in the subroutine ANALYS. */
    
    /* Input: */
    /*  SPEECH - Low pass filtered speech */
    /*           Indices 1 through MAX+LPITA-1 are read, where: */
    /*           MAX = (TAU(LTAU)-TAU(1))/2+1 */
    /*           (If TAU(1) .LT. 39, then larger indices could be read */
    /*           by the last call to DIFMAG below.) */
    /*  LPITA  - Length of speech buffer */
    /*  TAU    - Table of lags, sorted in increasing order. */
    /*           Indices 1 through LTAU read. */
    /*  LTAU   - Number of lag values to compute */
    /* Output: */
    /*  AMDF   - Average Magnitude Difference for each lag in TAU */
    /*          Indices 1 through LTAU written, and several might then be read.*/
    /*  MINPTR - Index of minimum AMDF value */
    /*  MAXPTR - Index of maximum AMDF value within +/- 1/2 octave of min */
    /*  MINTAU - Lag corresponding to minimum AMDF value */
    
    /* This subroutine has no local state. */
    
    /* Subroutine */ int tbdm_(real *speech, integer *lpita, integer *tau, 
    	integer *ltau, real *amdf, integer *minptr, integer *maxptr, integer *
    	mintau)
    {
        /* System generated locals */
        integer i__1, i__2, i__3, i__4;
    
        /* Local variables */
        real amdf2[6];
        integer minp2, ltau2, maxp2, i__;
        extern /* Subroutine */ int difmag_(real *, integer *, integer *, integer 
    	    *, integer *, real *, integer *, integer *);
        integer minamd, ptr, tau2[6];
    
    /* 	Arguments */
    /* 	REAL SPEECH(LPITA+TAU(LTAU)), AMDF(LTAU) */
    /*   Stupid TOAST doesn't understand expressions */
    /*       Local variables that need not be saved */
    /*       Local state */
    /*       None */
    /*   Compute full AMDF using log spaced lags, find coarse minimum */
        /* Parameter adjustments */
        --speech;
        --amdf;
        --tau;
    
        /* Function Body */
        difmag_(&speech[1], lpita, &tau[1], ltau, &tau[*ltau], &amdf[1], minptr, 
    	    maxptr);
        *mintau = tau[*minptr];
        minamd = amdf[*minptr];
    /*   Build table containing all lags within +/- 3 of the AMDF minimum */
    /*    excluding all that have already been computed */
        ltau2 = 0;
        ptr = *minptr - 2;
    /* Computing MAX */
        i__1 = *mintau - 3;
    /* Computing MIN */
        i__3 = *mintau + 3, i__4 = tau[*ltau] - 1;
        i__2 = min(i__3,i__4);
        for (i__ = max(i__1,41); i__ <= i__2; ++i__) {
    	while(tau[ptr] < i__) {
    	    ++ptr;
    	}
    	if (tau[ptr] != i__) {
    	    ++ltau2;
    	    tau2[ltau2 - 1] = i__;
    	}
        }
    /*   Compute AMDF of the new lags, if there are any, and choose one */
    /*    if it is better than the coarse minimum */
        if (ltau2 > 0) {
    	difmag_(&speech[1], lpita, tau2, &ltau2, &tau[*ltau], amdf2, &minp2, &
    		maxp2);
    	if (amdf2[minp2 - 1] < (real) minamd) {
    	    *mintau = tau2[minp2 - 1];
    	    minamd = amdf2[minp2 - 1];
    	}
        }
    /*   Check one octave up, if there are any lags not yet computed */
        if (*mintau >= 80) {
    	i__ = *mintau / 2;
    	if ((i__ & 1) == 0) {
    	    ltau2 = 2;
    	    tau2[0] = i__ - 1;
    	    tau2[1] = i__ + 1;
    	} else {
    	    ltau2 = 1;
    	    tau2[0] = i__;
    	}
    	difmag_(&speech[1], lpita, tau2, &ltau2, &tau[*ltau], amdf2, &minp2, &
    		maxp2);
    	if (amdf2[minp2 - 1] < (real) minamd) {
    	    *mintau = tau2[minp2 - 1];
    	    minamd = amdf2[minp2 - 1];
    	    *minptr += -20;
    	}
        }
    /*   Force minimum of the AMDF array to the high resolution minimum */
        amdf[*minptr] = (real) minamd;
    /*   Find maximum of AMDF within 1/2 octave of minimum */
    /* Computing MAX */
        i__2 = *minptr - 5;
        *maxptr = max(i__2,1);
    /* Computing MIN */
        i__1 = *minptr + 5;
        i__2 = min(i__1,*ltau);
        for (i__ = *maxptr + 1; i__ <= i__2; ++i__) {
    	if (amdf[i__] > amdf[*maxptr]) {
    	    *maxptr = i__;
    	}
        }
        return 0;
    } /* tbdm_ */