libsent/src/phmm/outprob_init.c

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/*
 * Copyright (c) 1991-2007 Kawahara Lab., Kyoto University
 * Copyright (c) 2000-2005 Shikano Lab., Nara Institute of Science and Technology
 * Copyright (c) 2005-2007 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>


boolean
outprob_init(HMMWork *wrk, HTK_HMM_INFO *hmminfo,
             HTK_HMM_INFO *gshmm, int gms_num,
             int gprune_method, int gprune_mixnum
             )
{
  /* check if variances are inversed */
  if (!hmminfo->variance_inversed) {
    /* here, inverse all variance values for faster computation */
    htk_hmm_inverse_variances(hmminfo);
    hmminfo->variance_inversed = TRUE;
  }
  /* check if variances are inversed */
  if (gshmm) {
    if (!gshmm->variance_inversed) {
      /* here, inverse all variance values for faster computation */
      htk_hmm_inverse_variances(gshmm);
      gshmm->variance_inversed = TRUE;
    }
  }

  /* select pruning function to compute likelihood of a mixture component
     and set the pointer to global */
  switch(gprune_method) {
  case GPRUNE_SEL_NONE:
    wrk->compute_gaussset = gprune_none;
    wrk->compute_gaussset_init = gprune_none_init;
    wrk->compute_gaussset_free = gprune_none_free;
    break;
  case GPRUNE_SEL_SAFE:
    wrk->compute_gaussset = gprune_safe;
    wrk->compute_gaussset_init = gprune_safe_init;
    wrk->compute_gaussset_free = gprune_safe_free;
    break;
  case GPRUNE_SEL_HEURISTIC:
    wrk->compute_gaussset = gprune_heu;
    wrk->compute_gaussset_init = gprune_heu_init;
    wrk->compute_gaussset_free = gprune_heu_free;
    break;
  case GPRUNE_SEL_BEAM:
    wrk->compute_gaussset = gprune_beam;
    wrk->compute_gaussset_init = gprune_beam_init;
    wrk->compute_gaussset_free = gprune_beam_free;
    break;
  }
  /* select caching function to compute output probability of a mixture */
  if (hmminfo->is_tied_mixture) {
    wrk->calc_outprob = calc_tied_mix; /* enable book-level cache, typically for a tied-mixture model */
  } else {
    wrk->calc_outprob = calc_mix; /* no mixture-level cache, for a shared-state, non tied-mixture model */
  }
  
  /* select back-off functon for state probability calculation */
  if (gshmm != NULL) {
    wrk->calc_outprob_state = gms_state; /* enable GMS */
  } else {
    wrk->calc_outprob_state = wrk->calc_outprob; /* call mixture outprob directly */
  }

  /* store common variable to global */
  wrk->OP_hmminfo = hmminfo;
  wrk->OP_gshmm = gshmm;                /* NULL if GMS not used */
  wrk->OP_gprune_num = gprune_mixnum;

  /* generate addlog table */
  make_log_tbl();
  
  /* initialize work area for mixture component pruning function */
  if ((*(wrk->compute_gaussset_init))(wrk) == FALSE) return FALSE; /* OP_gprune may change */
  /* initialize work area for book level cache on tied-mixture model */
  if (hmminfo->is_tied_mixture) {
    if (calc_tied_mix_init(wrk) == FALSE) return FALSE;
  }
  /* initialize work area for GMS */
  if (wrk->OP_gshmm != NULL) {
    wrk->my_nbest = gms_num;
    if (gms_init(wrk) == FALSE) return FALSE;
  }
  /* initialize cache for all output probabilities */
  if (outprob_cache_init(wrk) == FALSE)  return FALSE;

  /* initialize word area for computation of pseudo HMM set when N-max is specified */
  if (hmminfo->cdset_method == IWCD_NBEST) {
    outprob_cd_nbest_init(wrk, hmminfo->cdmax_num);
  }

  return TRUE;
}

boolean
outprob_prepare(HMMWork *wrk, int framenum)
{
  if (outprob_cache_prepare(wrk) == FALSE) return FALSE;
  if (wrk->OP_gshmm != NULL) {
    if (gms_prepare(wrk, framenum) == FALSE) return FALSE;
  }
  if (wrk->OP_hmminfo->is_tied_mixture) {
    if (calc_tied_mix_prepare(wrk, framenum) == FALSE) return FALSE;
  }
  /* reset last time */
  wrk->OP_last_time = wrk->OP_time = -1;
  return TRUE;
}

void
outprob_free(HMMWork *wrk)
{
  (*(wrk->compute_gaussset_free))(wrk);
  if (wrk->OP_hmminfo->is_tied_mixture) {
    calc_tied_mix_free(wrk);
  }
  if (wrk->OP_gshmm != NULL) {
    gms_free(wrk);
  }
  outprob_cache_free(wrk);
  if (wrk->OP_hmminfo->cdset_method == IWCD_NBEST) {
    outprob_cd_nbest_free(wrk);
  }

}

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