lpc10/difmag.c

   1 /*
   2
   3  * Revision 1.1  1996/08/19  22:32:31  jaf
   4  * Initial revision
   5  *
   6
   7 */
   8
   9 /*  -- translated by f2c (version 19951025).
  10    You must link the resulting object file with the libraries:
  11         -lf2c -lm   (in that order)
  12 */
  13
  14 #include "f2c.h"
  15
  16 extern int difmag_(real *speech, integer *lpita, integer *tau, integer *ltau, integer *maxlag, real *amdf, integer *minptr, integer *maxptr);
  17
  18 /* ********************************************************************** */
  19
  20 /*      DIFMAG Version 49 */
  21
  22 /*
  23  * Revision 1.1  1996/08/19  22:32:31  jaf
  24  * Initial revision
  25  * */
  26 /* Revision 1.3  1996/03/15  23:09:39  jaf */
  27 /* Just added a few comments about which array indices of the arguments */
  28 /* are used, and mentioning that this subroutine has no local state. */
  29
  30 /* Revision 1.2  1996/03/13  14:41:31  jaf */
  31 /* Comments added explaining that none of the local variables of this */
  32 /* subroutine need to be saved from one invocation to the next. */
  33
  34 /* Revision 1.1  1996/02/07 14:45:04  jaf */
  35 /* Initial revision */
  36
  37
  38 /* ********************************************************************* */
  39
  40 /*  Compute Average Magnitude Difference Function */
  41
  42 /* Inputs: */
  43 /*  SPEECH - Low pass filtered speech */
  44 /*           Indices MIN_N1 through MAX_N1+LPITA-1 are read, where */
  45 /*      MIN_N1 = (MAXLAG - MAX_TAU)/2+1  MAX_TAU = max of TAU(I) for I=1,LTAU
  46 */
  47 /*      MAX_N1 = (MAXLAG - MIN_TAU)/2+1  MIN_TAU = min of TAU(I) for I=1,LTAU
  48 */
  49 /*  LPITA  - Length of speech buffer */
  50 /*  TAU    - Table of lags */
  51 /*           Indices 1 through LTAU read. */
  52 /*  LTAU   - Number of lag values to compute */
  53 /*  MAXLAG - Maximum possible lag value */
  54 /* Outputs: */
  55 /*  (All of these outputs are also read, but only after being written.) */
  56 /*  AMDF   - Average Magnitude Difference for each lag in TAU */
  57 /*           Indices 1 through LTAU written */
  58 /*  MINPTR - Index of minimum AMDF value */
  59 /*  MAXPTR - Index of maximum AMDF value */
  60
  61 /* This subroutine has no local state. */
  62
  63 /* Subroutine */ int difmag_(real *speech, integer *lpita, integer *tau,
  64         integer *ltau, integer *maxlag, real *amdf, integer *minptr, integer *
  65         maxptr)
  66 {
  67     /* System generated locals */
  68     integer i__1, i__2;
  69     real r__1;
  70
  71     /* Local variables */
  72     integer i__, j, n1, n2;
  73     real sum;
  74
  75 /*       Arguments */
  76 /*       Local variables that need not be saved */
  77 /*       Local state */
  78 /*       None */
  79     /* Parameter adjustments */
  80     --amdf;
  81     --tau;
  82     --speech;
  83
  84     /* Function Body */
  85     *minptr = 1;
  86     *maxptr = 1;
  87     i__1 = *ltau;
  88     for (i__ = 1; i__ <= i__1; ++i__) {
  89         n1 = (*maxlag - tau[i__]) / 2 + 1;
  90         n2 = n1 + *lpita - 1;
  91         sum = 0.f;
  92         i__2 = n2;
  93         for (j = n1; j <= i__2; j += 4) {
  94             sum += (r__1 = speech[j] - speech[j + tau[i__]], abs(r__1));
  95         }
  96         amdf[i__] = sum;
  97         if (amdf[i__] < amdf[*minptr]) {
  98             *minptr = i__;
  99         }
 100         if (amdf[i__] > amdf[*maxptr]) {
 101             *maxptr = i__;
 102         }
 103     }
 104     return 0;
 105 } /* difmag_ */
 106