ref: 3e4bb567ba239293df67d1995aaef21c38d3272c
dir: /lpc10/tbdm.c/
/*
* Revision 1.1 1996/08/19 22:30:26 jaf
* Initial revision
*
*/
/* -- translated by f2c (version 19951025).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
extern int tbdm_(real *speech, integer *lpita, integer *tau, integer *ltau, real *amdf, integer *minptr, integer *maxptr, integer *mintau);
/* ********************************************************************** */
/* TBDM Version 49 */
/*
* 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, <au2, &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, <au2, &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_ */