libsent/src/phmm/calc_mix.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_hmm.h>
#include <sent/htk_param.h>
#include <sent/hmm.h>
#include <sent/hmm_calc.h>

LOGPROB
calc_mix(HMMWork *wrk)
{
  int i;
  LOGPROB logprob, logprobsum;
  PROB *w;
  int *id;
  int s;
  PROB stream_weight;

  /* compute Gaussian set */
  logprobsum = 0.0;
  for(s=0;s<wrk->OP_nstream;s++) {
    /* set stream weight */
    if (wrk->OP_state->w) stream_weight = wrk->OP_state->w->weight[s];
    else stream_weight = 1.0;
    /* setup storage pointer for this mixture pdf */
    wrk->OP_vec = wrk->OP_vec_stream[s];
    wrk->OP_veclen = wrk->OP_veclen_stream[s];
    /* compute output probabilities */
    /* computed Gaussians will be set in:
       score ... OP_calced_score[0..OP_calced_num]
       id    ... OP_calced_id[0..OP_calced_num] */    
    (*(wrk->compute_gaussset))(wrk, wrk->OP_state->pdf[s]->b, wrk->OP_state->pdf[s]->mix_num, NULL, 0);
    /* add weights */
    id = wrk->OP_calced_id;
    w = wrk->OP_state->pdf[s]->bweight;
    for(i=0;i<wrk->OP_calced_num;i++) {
      //printf("s%d-m%d: %f %f\n", s+1, i+1, wrk->OP_calced_score[i], w[id[i]]);
      wrk->OP_calced_score[i] += w[id[i]];
    }
    /* add log probs */
    logprob = addlog_array(wrk->OP_calced_score, wrk->OP_calced_num);
    /* if outprob of a stream is zero, skip this stream */
    if (logprob <= LOG_ZERO) continue;
    /* sum all the obtained mixture scores */
    logprobsum += logprob * stream_weight;
  }
  if (logprobsum == 0.0) return(LOG_ZERO); /* no valid stream */
  if (logprobsum <= LOG_ZERO) return(LOG_ZERO); /* lowest == LOG_ZERO */
  return (logprobsum * INV_LOG_TEN);
}