ref: c7709bad17ca756694a68aed2696f993ed9056ce
dir: /lpc10/onset.c/
/*
* Revision 1.2 1996/08/20 20:37:55 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Removed init function, since all initialization is now done in
* init_lpc10_encoder_state().
*
* Revision 1.1 1996/08/19 22:31:18 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 onset_(real *pebuf, integer *osbuf, integer *osptr, integer *oslen, integer *sbufl, integer *sbufh, integer *lframe, struct lpc10_encoder_state *st);
/* Table of constant values */
static real c_b2 = 1.f;
/* ****************************************************************** */
/* ONSET Version 49 */
/* Revision 1.2 1996/08/20 20:37:55 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Removed init function, since all initialization is now done in
* init_lpc10_encoder_state().
*
* Revision 1.1 1996/08/19 22:31:18 jaf
* Initial revision
* */
/* Revision 1.5 1996/03/15 16:41:01 jaf */
/* Just rearranged INITONSET assignment orders to be consistent with */
/* order of DATA statements in ONSET. */
/* Revision 1.4 1996/03/15 15:48:27 jaf */
/* Changed some comments, and only reordered the DATA statements (their */
/* meaning wasn't changed). */
/* Revision 1.3 1996/03/14 23:53:06 jaf */
/* Added an entry INITONSET that reinitializes the local state variables */
/* of subroutine ONSET. */
/* Rearranged quite a few comments, adding more explaining which */
/* arguments were inputs, and how the modified ones can be changed. */
/* Revision 1.2 1996/03/12 23:53:00 jaf */
/* Lots of comments added about the local state of this subroutine that */
/* must be saved from one invocation to the next. */
/* One constant 180 replaced with LFRAME, which should be "more general", */
/* even though it would probably require many more changes than this to */
/* get this coder to work for other frame sizes. */
/* Revision 1.1 1996/02/07 14:48:09 jaf */
/* Initial revision */
/* ****************************************************************** */
/* Floating point version */
/* Detection of onsets in (or slightly preceding) the futuremost frame */
/* of speech. */
/* Input: */
/* PEBUF(SBUFL:SBUFH) - Preemphasized speech */
/* Indices SBUFH-LFRAME through SBUFH are read. */
/* OSLEN - Maximum number of onsets that can be stored in OSBUF. */
/* SBUFL, SBUFH - Range of PEBUF */
/* LFRAME - length of a frame, in samples */
/* Input/Output: */
/* OSBUF(OSLEN) - Buffer which holds sorted indexes of onsets */
/* Indices A through B are modified, where A */
/* is the original value of OSPTR, and B is the final */
/* value of OSPTR-1. B is at most OSLEN. */
/* OSPTR - Free pointer into OSBUF */
/* Initial value should be .LE. OSLEN+1. */
/* If so, final value grows by one for each new onset */
/* found, and final value will be .LE. OSLEN+1. */
/* This subroutine maintains local state from one call to the next. If */
/* you want to switch to using a new audio stream for this subroutine, or */
/* reinitialize its state for any other reason, call the ENTRY INITONSET. */
/* Subroutine */ int onset_(real *pebuf, integer *osbuf, integer *
osptr, integer *oslen, integer *sbufl, integer *sbufh, integer *
lframe, struct lpc10_encoder_state *st)
{
/* Initialized data */
real *n;
real *d__;
real *l2buf;
real *l2sum1;
integer *l2ptr1;
integer *l2ptr2;
logical *hyst;
/* System generated locals */
integer pebuf_offset, i__1;
real r__1;
/* Builtin functions */
double r_sign(real *, real *);
/* Local variables */
integer i__;
integer *lasti;
real l2sum2;
real *fpc;
/* Arguments */
/* LPC Configuration parameters: */
/* Frame size, Prediction order, Pitch period */
/* Parameters/constants */
/* Parameters for onset detection algorithm: */
/* L2 Threshold for filtered slope of FPC (function of L2WID!) */
/* L2LAG Lag due to both filters which compute filtered slope of FPC */
/* L2WID Width of the filter which computes the slope of FPC */
/* OSHYST The number of samples of slope(FPC) which must be below */
/* the threshold before a new onset may be declared. */
/* Local variables that need not be saved */
/* Local state */
/* Variables */
/* N, D Numerator and denominator of prediction filters */
/* FPC Current prediction coefs */
/* L2BUF, L2SUM1, L2SUM2 State of slope filter */
/* The only "significant" change I've made is to change L2SUM2 out
*/
/* of the list of local variables that need to be saved, since it */
/* didn't need to be. */
/* L2SUM1 need not be, but avoiding saving it would require a small
*/
/* change to the body of the code. See comments below for an */
/* example of how the code could be changed to avoid saving L2SUM1.
*/
/* FPC and LASTI are saved from one invocation to the next, but */
/* they are not given initial values. This is acceptable, because
*/
/* FPC will be assigned a value the first time that this function */
/* is called after D is initialized to 1, since the formula to */
/* change D will not change it to 0 in one step, and the IF (D */
/* .NE. 0) statement will execute its THEN part, initializing FPC.
*/
/* LASTI's value will not be used until HYST is .TRUE., and */
/* whenever HYST is changed from its initial value of .FALSE., */
/* LASTI is assigned a value. */
/* In a C version of this coder, it would be nice if all of these */
/* saved things, in this and all other subroutines, could be stored
*/
/* in a single struct lpc10_coder_state_t, initialized with a call
*/
/* to a function like lpc10_init(&lpc10_coder_state). In this way,
*/
/* a program that used these functions could conveniently alternate
*/
/* coding more than one distinct audio stream. */
n = &(st->n);
d__ = &(st->d__);
fpc = &(st->fpc);
l2buf = &(st->l2buf[0]);
l2sum1 = &(st->l2sum1);
l2ptr1 = &(st->l2ptr1);
l2ptr2 = &(st->l2ptr2);
lasti = &(st->lasti);
hyst = &(st->hyst);
/* Parameter adjustments */
if (osbuf) {
--osbuf;
}
if (pebuf) {
pebuf_offset = *sbufl;
pebuf -= pebuf_offset;
}
/* Function Body */
/* The following line subtracted a hard-coded "180" from LASTI, */
/* instead of using a variable like LFRAME or a constant like */
/* MAXFRM. I changed it to LFRAME, for "generality". */
if (*hyst) {
*lasti -= *lframe;
}
i__1 = *sbufh;
for (i__ = *sbufh - *lframe + 1; i__ <= i__1; ++i__) {
/* Compute FPC; Use old FPC on divide by zero; Clamp FPC to +/- 1.
*/
*n = (pebuf[i__] * pebuf[i__ - 1] + (*n) * 63.f) / 64.f;
/* Computing 2nd power */
r__1 = pebuf[i__ - 1];
*d__ = (r__1 * r__1 + (*d__) * 63.f) / 64.f;
if ((*d__) != 0.f) {
if (abs(*n) > (*d__)) {
*fpc = r_sign(&c_b2, n);
} else {
*fpc = (*n) / (*d__);
}
}
/* Filter FPC */
/* In order to allow L2SUM1 not to be saved from one invocation
of */
/* this subroutine to the next, one could change the sequence of
*/
/* assignments below, up to the IF statement, to the following.
In */
/* addition, the initial value of L2PTR2 should be changed to */
/* L2WID/2 instead of L2WID/2+1. */
/* L2SUM1 = L2BUF(L2PTR2) */
/* L2PTR2 = MOD(L2PTR2,L2WID)+1 */
/* L2SUM1 = L2SUM1 - L2BUF(L2PTR2) + FPC */
/* L2BUF(L2PTR2) = L2SUM1 */
/* * The following lines didn't change from the original: */
/* L2SUM2 = L2BUF(L2PTR1) */
/* L2BUF(L2PTR1) = FPC */
/* L2PTR1 = MOD(L2PTR1,L2WID)+1 */
l2sum2 = l2buf[*l2ptr1 - 1];
*l2sum1 = *l2sum1 - l2buf[*l2ptr2 - 1] + *fpc;
l2buf[*l2ptr2 - 1] = *l2sum1;
l2buf[*l2ptr1 - 1] = *fpc;
*l2ptr1 = *l2ptr1 % 16 + 1;
*l2ptr2 = *l2ptr2 % 16 + 1;
if ((r__1 = *l2sum1 - l2sum2, abs(r__1)) > 1.7f) {
if (! (*hyst)) {
/* Ignore if buffer full */
if (*osptr <= *oslen) {
osbuf[*osptr] = i__ - 9;
++(*osptr);
}
*hyst = TRUE_;
}
*lasti = i__;
/* After one onset detection, at least OSHYST sample times m
ust go */
/* by before another is allowed to occur. */
} else if ((*hyst) && i__ - *lasti >= 10) {
*hyst = FALSE_;
}
}
return 0;
} /* onset_ */