lpc10/onset.c

   1 /*
   2
   3  * Revision 1.2  1996/08/20  20:37:55  jaf
   4  * Removed all static local variables that were SAVE'd in the Fortran
   5  * code, and put them in struct lpc10_encoder_state that is passed as an
   6  * argument.
   7  *
   8  * Removed init function, since all initialization is now done in
   9  * init_lpc10_encoder_state().
  10  *
  11  * Revision 1.1  1996/08/19  22:31:18  jaf
  12  * Initial revision
  13  *
  14
  15 */
  16
  17 /*  -- translated by f2c (version 19951025).
  18    You must link the resulting object file with the libraries:
  19         -lf2c -lm   (in that order)
  20 */
  21
  22 #include "f2c.h"
  23
  24 extern int onset_(real *pebuf, integer *osbuf, integer *osptr, integer *oslen, integer *sbufl, integer *sbufh, integer *lframe, struct lpc10_encoder_state *st);
  25
  26 /* Table of constant values */
  27
  28 static real c_b2 = 1.f;
  29
  30 /* ****************************************************************** */
  31
  32 /*      ONSET Version 49 */
  33
  34 /* Revision 1.2  1996/08/20  20:37:55  jaf
  35  * Removed all static local variables that were SAVE'd in the Fortran
  36  * code, and put them in struct lpc10_encoder_state that is passed as an
  37  * argument.
  38  *
  39  * Removed init function, since all initialization is now done in
  40  * init_lpc10_encoder_state().
  41  *
  42  * Revision 1.1  1996/08/19  22:31:18  jaf
  43  * Initial revision
  44  * */
  45 /* Revision 1.5  1996/03/15  16:41:01  jaf */
  46 /* Just rearranged INITONSET assignment orders to be consistent with */
  47 /* order of DATA statements in ONSET. */
  48
  49 /* Revision 1.4  1996/03/15  15:48:27  jaf */
  50 /* Changed some comments, and only reordered the DATA statements (their */
  51 /* meaning wasn't changed). */
  52
  53 /* Revision 1.3  1996/03/14  23:53:06  jaf */
  54 /* Added an entry INITONSET that reinitializes the local state variables */
  55 /* of subroutine ONSET. */
  56
  57 /* Rearranged quite a few comments, adding more explaining which */
  58 /* arguments were inputs, and how the modified ones can be changed. */
  59
  60 /* Revision 1.2  1996/03/12  23:53:00  jaf */
  61 /* Lots of comments added about the local state of this subroutine that */
  62 /* must be saved from one invocation to the next. */
  63
  64 /* One constant 180 replaced with LFRAME, which should be "more general", */
  65 /* even though it would probably require many more changes than this to */
  66 /* get this coder to work for other frame sizes. */
  67
  68 /* Revision 1.1  1996/02/07 14:48:09  jaf */
  69 /* Initial revision */
  70
  71
  72 /* ****************************************************************** */
  73
  74 /*      Floating point version */
  75
  76
  77 /*   Detection of onsets in (or slightly preceding) the futuremost frame */
  78 /*   of speech. */
  79
  80
  81 /* Input: */
  82 /*  PEBUF(SBUFL:SBUFH)  - Preemphasized speech */
  83 /*                        Indices SBUFH-LFRAME through SBUFH are read. */
  84 /*  OSLEN  - Maximum number of onsets that can be stored in OSBUF. */
  85 /*  SBUFL, SBUFH        - Range of PEBUF */
  86 /*  LFRAME              - length of a frame, in samples */
  87 /* Input/Output: */
  88 /*  OSBUF(OSLEN) - Buffer which holds sorted indexes of onsets */
  89 /*                 Indices A through B are modified, where A */
  90 /*                 is the original value of OSPTR, and B is the final */
  91 /*                 value of OSPTR-1.  B is at most OSLEN. */
  92 /*  OSPTR        - Free pointer into OSBUF */
  93 /*                 Initial value should be .LE. OSLEN+1. */
  94 /*                 If so, final value grows by one for each new onset */
  95 /*                 found, and final value will be .LE. OSLEN+1. */
  96
  97 /* This subroutine maintains local state from one call to the next.  If */
  98 /* you want to switch to using a new audio stream for this subroutine, or */
  99 /* reinitialize its state for any other reason, call the ENTRY INITONSET. */
 100
 101 /* Subroutine */ int onset_(real *pebuf, integer *osbuf, integer *
 102         osptr, integer *oslen, integer *sbufl, integer *sbufh, integer *
 103         lframe, struct lpc10_encoder_state *st)
 104 {
 105     /* Initialized data */
 106
 107     real *n;
 108     real *d__;
 109     real *l2buf;
 110     real *l2sum1;
 111     integer *l2ptr1;
 112     integer *l2ptr2;
 113     logical *hyst;
 114
 115     /* System generated locals */
 116     integer pebuf_offset, i__1;
 117     real r__1;
 118
 119     /* Builtin functions */
 120     double r_sign(real *, real *);
 121
 122     /* Local variables */
 123     integer i__;
 124     integer *lasti;
 125     real l2sum2;
 126     real *fpc;
 127
 128 /*       Arguments */
 129
 130 /*   LPC Configuration parameters: */
 131 /* Frame size, Prediction order, Pitch period */
 132 /*       Parameters/constants */
 133 /*   Parameters for onset detection algorithm: */
 134 /*    L2                Threshold for filtered slope of FPC (function of L2WID!) */
 135 /*    L2LAG     Lag due to both filters which compute filtered slope of FPC */
 136 /*    L2WID     Width of the filter which computes the slope of FPC */
 137 /*    OSHYST    The number of samples of slope(FPC) which must be below */
 138 /*              the threshold before a new onset may be declared. */
 139 /*       Local variables that need not be saved */
 140 /*       Local state */
 141 /*   Variables */
 142 /*    N, D       Numerator and denominator of prediction filters */
 143 /*    FPC        Current prediction coefs */
 144 /*    L2BUF, L2SUM1, L2SUM2    State of slope filter */
 145 /*       The only "significant" change I've made is to change L2SUM2 out
 146 */
 147 /*       of the list of local variables that need to be saved, since it */
 148 /*       didn't need to be. */
 149 /*       L2SUM1 need not be, but avoiding saving it would require a small
 150 */
 151 /*       change to the body of the code.  See comments below for an */
 152 /*       example of how the code could be changed to avoid saving L2SUM1.
 153 */
 154 /*       FPC and LASTI are saved from one invocation to the next, but */
 155 /*       they are not given initial values.  This is acceptable, because
 156 */
 157 /*       FPC will be assigned a value the first time that this function */
 158 /*       is called after D is initialized to 1, since the formula to */
 159 /*       change D will not change it to 0 in one step, and the IF (D */
 160 /*       .NE. 0) statement will execute its THEN part, initializing FPC.
 161 */
 162
 163 /*       LASTI's value will not be used until HYST is .TRUE., and */
 164 /*       whenever HYST is changed from its initial value of .FALSE., */
 165 /*       LASTI is assigned a value. */
 166 /*       In a C version of this coder, it would be nice if all of these */
 167 /*       saved things, in this and all other subroutines, could be stored
 168 */
 169 /*       in a single struct lpc10_coder_state_t, initialized with a call
 170 */
 171 /*       to a function like lpc10_init(&lpc10_coder_state).  In this way,
 172 */
 173 /*       a program that used these functions could conveniently alternate
 174 */
 175 /*       coding more than one distinct audio stream. */
 176
 177     n = &(st->n);
 178     d__ = &(st->d__);
 179     fpc = &(st->fpc);
 180     l2buf = &(st->l2buf[0]);
 181     l2sum1 = &(st->l2sum1);
 182     l2ptr1 = &(st->l2ptr1);
 183     l2ptr2 = &(st->l2ptr2);
 184     lasti = &(st->lasti);
 185     hyst = &(st->hyst);
 186
 187     /* Parameter adjustments */
 188     if (osbuf) {
 189         --osbuf;
 190         }
 191     if (pebuf) {
 192         pebuf_offset = *sbufl;
 193         pebuf -= pebuf_offset;
 194         }
 195
 196     /* Function Body */
 197
 198 /*       The following line subtracted a hard-coded "180" from LASTI, */
 199 /*       instead of using a variable like LFRAME or a constant like */
 200 /*       MAXFRM.  I changed it to LFRAME, for "generality". */
 201     if (*hyst) {
 202         *lasti -= *lframe;
 203     }
 204     i__1 = *sbufh;
 205     for (i__ = *sbufh - *lframe + 1; i__ <= i__1; ++i__) {
 206 /*   Compute FPC; Use old FPC on divide by zero; Clamp FPC to +/- 1.
 207 */
 208         *n = (pebuf[i__] * pebuf[i__ - 1] + (*n) * 63.f) / 64.f;
 209 /* Computing 2nd power */
 210         r__1 = pebuf[i__ - 1];
 211         *d__ = (r__1 * r__1 + (*d__) * 63.f) / 64.f;
 212         if ((*d__) != 0.f) {
 213             if (abs(*n) > (*d__)) {
 214                 *fpc = r_sign(&c_b2, n);
 215             } else {
 216                 *fpc = (*n) / (*d__);
 217             }
 218         }
 219 /*   Filter FPC */
 220 /*       In order to allow L2SUM1 not to be saved from one invocation
 221 of */
 222 /*       this subroutine to the next, one could change the sequence of
 223  */
 224 /*       assignments below, up to the IF statement, to the following.
 225  In */
 226 /*       addition, the initial value of L2PTR2 should be changed to */
 227 /*       L2WID/2 instead of L2WID/2+1. */
 228
 229 /*       L2SUM1 = L2BUF(L2PTR2) */
 230 /*       L2PTR2 = MOD(L2PTR2,L2WID)+1 */
 231 /*       L2SUM1 = L2SUM1 - L2BUF(L2PTR2) + FPC */
 232 /*       L2BUF(L2PTR2) = L2SUM1 */
 233
 234 /* *       The following lines didn't change from the original: */
 235 /*       L2SUM2 = L2BUF(L2PTR1) */
 236 /*       L2BUF(L2PTR1) = FPC */
 237 /*       L2PTR1 = MOD(L2PTR1,L2WID)+1 */
 238
 239         l2sum2 = l2buf[*l2ptr1 - 1];
 240         *l2sum1 = *l2sum1 - l2buf[*l2ptr2 - 1] + *fpc;
 241         l2buf[*l2ptr2 - 1] = *l2sum1;
 242         l2buf[*l2ptr1 - 1] = *fpc;
 243         *l2ptr1 = *l2ptr1 % 16 + 1;
 244         *l2ptr2 = *l2ptr2 % 16 + 1;
 245         if ((r__1 = *l2sum1 - l2sum2, abs(r__1)) > 1.7f) {
 246             if (! (*hyst)) {
 247 /*   Ignore if buffer full */
 248                 if (*osptr <= *oslen) {
 249                     osbuf[*osptr] = i__ - 9;
 250                     ++(*osptr);
 251                 }
 252                 *hyst = TRUE_;
 253             }
 254             *lasti = i__;
 255 /*       After one onset detection, at least OSHYST sample times m
 256 ust go */
 257 /*       by before another is allowed to occur. */
 258         } else if ((*hyst) && i__ - *lasti >= 10) {
 259             *hyst = FALSE_;
 260         }
 261     }
 262     return 0;
 263 } /* onset_ */