libsent/src/adin/zc-e.c

説明を見る。

/*
 * Copyright (c) 1991-2011 Kawahara Lab., Kyoto University
 * Copyright (c) 2000-2005 Shikano Lab., Nara Institute of Science and Technology
 * Copyright (c) 2005-2011 Julius project team, Nagoya Institute of Technology
 * All rights reserved
 */

/* Sat Feb 19 13:48:00 JST 1994 */
/*  Kawahara 1986 */
/*  Munetsugu 1991 */
/*  shinohara 1993 */
/*  mikik 1993 */
/*  ri 1997 for cycle buffer */

#include <sent/stddefs.h>
#include <sent/adin.h>

void
init_count_zc_e(ZEROCROSS *zc, int length)
{
  /* data spool for header-margin */
  zc->data = (SP16 *)mymalloc(length * sizeof(SP16));
  /* zero-cross location */
  zc->is_zc = (int *)mymalloc(length * sizeof(int));

  zc->length = length;
}

void
reset_count_zc_e(ZEROCROSS *zc, int c_trigger, int c_length, int c_offset)
{
  int i;

  if (zc->length != c_length) {
    jlog("Warning: zerocross buffer length changed, re-allocate it\n");
    free_count_zc_e(zc);
    init_count_zc_e(zc, c_length);
  }

  zc->trigger = c_trigger;
  zc->offset = c_offset;

  zc->zero_cross = 0;
  zc->is_trig = FALSE;
  zc->sign = ZC_POSITIVE;
  zc->top = 0;
  zc->valid_len = 0;

  for (i=0; i<c_length; i++){
    zc->is_zc[i] = ZC_UNDEF;
  }
}

void
free_count_zc_e(ZEROCROSS *zc)
{
  free(zc->is_zc);
  free(zc->data);
}

int
count_zc_e(ZEROCROSS *zc, SP16 *buf, int step)
{
  int i;
  SP16 tmp, level;

  level = 0;
  for (i=0; i<step; i++) {
    if (zc->is_zc[zc->top] == TRUE) {
      zc->zero_cross--;
    }
    zc->is_zc[zc->top] = FALSE;
    /* exchange old data and buf */
    tmp = buf[i] + zc->offset;
    if (zc->is_trig) {
      if (zc->sign == ZC_POSITIVE && tmp < 0) {
        zc->zero_cross++;
        zc->is_zc[zc->top] = TRUE;
        zc->is_trig = FALSE;
        zc->sign = ZC_NEGATIVE;
      } else if (zc->sign == ZC_NEGATIVE && tmp > 0) {
        zc->zero_cross++;
        zc->is_zc[zc->top] = TRUE;
        zc->is_trig = FALSE;
        zc->sign = ZC_POSITIVE;
      }
    }
    if (abs(tmp) > zc->trigger) {
      zc->is_trig = TRUE;
    }
    if (abs(tmp) > level) level = abs(tmp);
    zc->data[zc->top] = buf[i];
    zc->top++;
    if (zc->valid_len < zc->top) zc->valid_len = zc->top;
    if (zc->top >= zc->length) {
      zc->top = 0;
    }
  }
  zc->level = (int)level;
  return (zc->zero_cross);
}

void
zc_copy_buffer(ZEROCROSS *zc, SP16 *newbuf, int *len)
{
  int i, t;
  if (zc->valid_len < zc->length) {
    t = 0;
  } else {
    t = zc->top;
  }
  for(i=0;i<zc->valid_len;i++) {
    newbuf[i] = zc->data[t];
    if (++t == zc->length) t = 0;
  }
  *len = zc->valid_len;
}