libsent/src/anlz/strip_mfcc.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
 */

#include <sent/stddefs.h>
#include <sent/htk_param.h>
#include <sent/mfcc.h>

#define IS_INVALID_FRAME_MFCC(A) ((A) < -30.0 || (A) > 30.0)

static int
guess_abs_e_location(HTK_Param *param)
{
  short qualtype;
  int basenum, abs_e_num;
  qualtype = param->header.samptype & ~(F_COMPRESS | F_CHECKSUM);
  qualtype &= ~(F_BASEMASK);
  basenum = guess_basenum(param, qualtype);
  if (qualtype & F_ENERGY) {
    if (qualtype & F_ZEROTH) {
      abs_e_num = basenum + 1;
    } else {
      abs_e_num = basenum;
    }
  } else {
    /* absolute energy not included */
    jlog("Stat: strip_mfcc: absolute energy coef. not exist, stripping disabled\n");
    abs_e_num = -1;
  }
  return abs_e_num;
}

boolean
param_strip_zero(HTK_Param *param)
{
  unsigned int src,dst;
  int eloc;

  /* guess where the absolute energy coefficient is */
  eloc = guess_abs_e_location(param);
  if ((eloc = guess_abs_e_location(param)) < 0) return FALSE;
    
  /* guess the invalid range... */
  dst = 0;
  for(src=0;src<param->samplenum;src++) {
    if (IS_INVALID_FRAME_MFCC(param->parvec[src][eloc])) {
      jlog("Warning: strip_mfcc: frame %d has invalid energy, stripped\n", src);
      continue;
    }
    if (src != dst) {
      memcpy(param->parvec[dst], param->parvec[src], sizeof(VECT) * param->veclen);
    }
    dst++;
  }
  if (dst != param->samplenum) {
    jlog("Warning: strip_mfcc: input shrinked from %d to %d frames\n", param->samplenum, dst);
    param->header.samplenum = param->samplenum = dst;
  }

  return TRUE;
}