zc-e.c

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/*
 * Copyright (c) 1991-2006 Kawahara Lab., Kyoto University
 * Copyright (c) 2000-2005 Shikano Lab., Nara Institute of Science and Technology
 * Copyright (c) 2005-2006 Julius project team, Nagoya Institute of Technology, 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>

#define UNDEF 2                 
#define POSITIVE 1              
#define NEGATIVE -1             

static int trigger;             
static int length;              
static int offset;              
static int *is_zc;              
static SP16 *data;              
static int zero_cross;          
static int sign;                
static int is_trig;             
static int top;                 
static int valid_len;           

void
init_count_zc_e(int c_trigger, int c_length, int c_offset)
{
  int i;

  trigger = c_trigger;
  length = c_length;
  offset = c_offset;

  zero_cross = 0;
  is_trig = FALSE;
  sign = POSITIVE;
  top = 0;
  valid_len = 0;

  /* data spool for header-margin */
  data = (SP16 *)mymalloc(length * sizeof(SP16));
  /* zero-cross location */
  is_zc = (int *)mymalloc(length * sizeof(int));
  for (i=0; i<length; i++){
    is_zc[i] = UNDEF;
  }
}

void
end_count_zc_e()
{
  free(is_zc);
  free(data);
}

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

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

int
count_zc_e_level(SP16 *buf,int step,int *levelp)
{
  int i;
  SP16 tmp, level;

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

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

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