/** * @file   gms.c * @author Akinobu LEE * @date   Thu Feb 17 14:52:18 2005 *  * <JA> * @brief  Gaussian Mixture Selection による覺輪銻刨紛換 * * 悸劉數(shù)恕についてはソ〖ス柒のコメントをご枉くださいˉ * </JA> *  * <EN> * @brief  Calculate state probability with Gaussian Mixture Selection * * See the comments in the source for details about implementation. * </EN> *  * $Revision: 1.4 $ *  *//* * 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 * All rights reserved *//*  Implementation of Gaussian Mixture Selection (old doc...)    It is called from gs_calc_selected_mixture_and_cache_{safe,heu,beam} in  the first pass for each frame.  It calculates all GS HMM outprob for  given input frame and get the N-best GS HMM states. Then,       for the selected (N-best) states:           calculate the corresponding codebook,           and set fallback_score[t][book] to LOG_ZERO.       else:           set fallback_score[t][book] to the GS HMM outprob.  Later, when calculating state outprobs, the fallback_score[t][book]  is consulted and,       if fallback_score[t][book] == LOG_ZERO:           it means it has been selected, so calculate the outprob with           the corresponding codebook and its weights.       else:           it means it was pruned, so use the fallback_score[t][book]           as its outprob.             For triphone, GS HMMs should be assigned to each state.  So the fallback_score[][] is kept according to the GS state ID,  and corresponding GS HMM state id for each triphone state id should be  kept beforehand.  GS HMM Calculation:       for the selected (N-best) GS HMM states:           set fallback_score[t][gs_stateid] to LOG_ZERO.       else:           set fallback_score[t][gs_stateid] to the GS HMM outprob.  triphone HMM probabilities are assigned as:       if fallback_score[t][state2gs[tri_stateid]] == LOG_ZERO:           it has been selected, so calculate the original outprob.       else:           as it was pruned, re-use the fallback_score[t][stateid]           as its outprob.*/#include <sent/stddefs.h>#include <sent/htk_hmm.h>#include <sent/htk_param.h>#include <sent/hmm.h>#include <sent/gprune.h>#include "globalvars.h"#undef NORMALIZE_GS_SCORE	/* normalize score (ad-hoc) */  /* GS HMMs must be defined at STATE level using "~s NAME" macro,     where NAMES are like "i:4m", "s2m", etc. *//* variables for GMS */static int my_nbest;		///< Number of states to be selectedstatic int allocframenum;	///< Allocated number of frame for storing fallback scores per frame/* GMS info */static GS_SET *gsset;		///< Set of GS statesstatic int gsset_num;		///< Num of abovestatic int *state2gs; ///< Mapping from triphone state id to gs id/* results */static boolean *is_selected;	///< TRUE if the frame is already selectedstatic LOGPROB **fallback_score = NULL; ///< [t][gssetid], LOG_ZERO if selected/* for calculation */static int *gsindex;		///< Index bufferstatic LOGPROB *t_fs;		///< Current fallback_score/**  * Register all state defs in GS HMM to GS_SET. *  */static voidbuild_gsset(){  HTK_HMM_State *st;  /* allocate */  gsset = (GS_SET *)mymalloc(sizeof(GS_SET) * OP_gshmm->totalstatenum);  gsset_num = OP_gshmm->totalstatenum;  /* make ID */  for(st = OP_gshmm->ststart; st; st=st->next) {    gsset[st->id].state = st;  }}/** * Free gsset. *  */static voidfree_gsset(){  free(gsset);}#define MAXHMMNAMELEN 40	///< Assumed maximum length of %HMM name/**  * Build the correspondence from GS states to triphone states. *  * @return TRUE on success, FALSE on failure. */static booleanbuild_state2gs(){  HTK_HMM_Data *dt;  HTK_HMM_State *st, *cr;  int i;  char gstr[MAXHMMNAMELEN], cbuf[MAXHMMNAMELEN];  boolean ok_p = TRUE;  /* initialize */  state2gs = (int *)mymalloc(sizeof(int) * OP_hmminfo->totalstatenum);  for(i=0;i<OP_hmminfo->totalstatenum;i++) state2gs[i] = -1;  /* parse through all HMM macro to register their state */  for(dt = OP_hmminfo->start; dt; dt=dt->next) {    if (strlen(dt->name) >= MAXHMMNAMELEN - 2) {      j_printerr("Error: too long hmm name (>%d): \"%s\"\n",		 MAXHMMNAMELEN-3, dt->name);      ok_p = FALSE;      continue;    }    for(i=1;i<dt->state_num-1;i++) { /* for all state */      st = dt->s[i];      /* skip if already assigned */      if (state2gs[st->id] != -1) continue;      /* set corresponding gshmm name */      sprintf(gstr, "%s%dm", center_name(dt->name, cbuf), i + 1);      /* look up the state in OP_gshmm */      if ((cr = state_lookup(OP_gshmm, gstr)) == NULL) {	j_printerr("Error: GS HMM \"%s\" not defined\n", gstr);	ok_p = FALSE;	continue;      }      /* store its ID */      state2gs[st->id] = cr->id;    }  }#ifdef PARANOIA  {    HTK_HMM_State *st;    for(st=OP_hmminfo->ststart; st; st=st->next) {      printf("%s -> %s\n", (st->name == NULL) ? "(NULL)" : st->name,	     (gsset[state2gs[st->id]].state)->name);    }  }#endif  return ok_p;}/** * free state2gs. *  */static voidfree_state2gs(){  free(state2gs);}/* sort to find N-best states */#define SD(A) gsindex[A-1]	///< Index macro for heap sort#define SCOPY(D,S) D = S	///< Element copy macro for heap sort#define SVAL(A) (t_fs[gsindex[A-1]]) ///< Element evaluation macro for heap sort#define STVAL (t_fs[s]) ///< Element current value macro for heap sort/**  * Heap sort of @a gsindex to determine which model gets N best likelihoods. *  * @param neednum [in] needed number N * @param totalnum [in] total number of data */static voidsort_gsindex_upward(int neednum, int totalnum){  int n,root,child,parent;  int s;  for (root = totalnum/2; root >= 1; root--) {    SCOPY(s, SD(root));    parent = root;    while ((child = parent * 2) <= totalnum) {      if (child < totalnum && SVAL(child) < SVAL(child+1)) {	child++;      }      if (STVAL >= SVAL(child)) {	break;      }      SCOPY(SD(parent), SD(child));      parent = child;    }    SCOPY(SD(parent), s);  }  n = totalnum;  while ( n > totalnum - neednum) {    SCOPY(s, SD(n));    SCOPY(SD(n), SD(1));    n--;    parent = 1;    while ((child = parent * 2) <= n) {      if (child < n && SVAL(child) < SVAL(child+1)) {	child++;      }      if (STVAL >= SVAL(child)) {	break;      }      SCOPY(SD(parent), SD(child));      parent = child;    }    SCOPY(SD(parent), s);  }}/**  * Calculate all GS state scores and select the best ones. *  */static voiddo_gms(){  int i;    /* compute all gshmm scores (in gs_score.c) */  compute_gs_scores(gsset, gsset_num, t_fs);  /* sort and select */  sort_gsindex_upward(my_nbest, gsset_num);  for(i=gsset_num - my_nbest;i<gsset_num;i++) {    /* set scores of selected states to LOG_ZERO */    t_fs[gsindex[i]] = LOG_ZERO;  }  /* power e -> 10 */#ifdef NORMALIZE_GS_SCORE  /* normalize other fallback scores (rate of max) */  for(i=0;i<gsset_num;i++) {    if (t_fs[i] != LOG_ZERO) {      t_fs[i] = t_fs[i] * 0.975;    }  }#endif}  /**  * Initialize the GMS related functions and data. *  * @param nbest [in] N-best state to compute the precise triphone. *  * @return TRUE on success, FALSE on failure. */booleangms_init(int nbest){  int i;    /* Check gshmm type */  if (OP_gshmm->is_triphone) {    j_printerr("Error: GS HMM should be a monophone model\n");    return FALSE;  }  if (OP_gshmm->is_tied_mixture) {    j_printerr("Error: GS HMM should not be a tied mixture model\n");    return FALSE;  }  /* store as local info */  my_nbest = nbest;  /* Register all GS HMM states in GS_SET */  build_gsset();  /* Make correspondence of all triphone states to GS HMM states */  j_printerr("Mapping HMM states to GS HMM...");  if (build_state2gs() == FALSE) {    j_printerr("Error: failed in assigning GS HMM state for each state\n");    return FALSE;  }  j_printerr("done\n");  /* prepare index buffer for heap sort */  gsindex = (int *)mymalloc(sizeof(int) * gsset_num);  for(i=0;i<gsset_num;i++) gsindex[i] = i;  /* init cache status */  fallback_score = NULL;  is_selected = NULL;  allocframenum = -1;  /* initialize gms_gprune functions */  gms_gprune_init(OP_hmminfo, gsset_num);    return TRUE;}/**  * Setup GMS parameters for next input. *  * @param framenum [in] length of next input in frames *  * @return TRUE on success, FALSE on failure. */booleangms_prepare(int framenum){  LOGPROB *tmp;  int t;  /* allocate cache */  if (allocframenum < framenum) {    if (fallback_score != NULL) {      free(fallback_score[0]);      free(fallback_score);      free(is_selected);    }    fallback_score = (LOGPROB **)mymalloc(sizeof(LOGPROB *) * framenum);    tmp = (LOGPROB *)mymalloc(sizeof(LOGPROB) * gsset_num * framenum);    for(t=0;t<framenum;t++) {      fallback_score[t] = &(tmp[gsset_num * t]);    }    is_selected = (boolean *)mymalloc(sizeof(boolean) * framenum);    allocframenum = framenum;  }  /* clear */  for(t=0;t<framenum;t++) is_selected[t] = FALSE;  /* prepare gms_gprune functions */  gms_gprune_prepare();    return TRUE;}/** * Free GMS related work areas. *  */voidgms_free(){  free_gsset();  free_state2gs();  free(gsindex);  if (fallback_score != NULL) {    free(fallback_score[0]);    free(fallback_score);    free(is_selected);  }  gms_gprune_free();}/**  * Get %HMM State probability of current state with Gaussiam Mixture Selection. * * If the GMS %HMM score of the corresponding basephone is below the * N-best, the triphone score will not be computed, and the score of * the GMS %HMM will be returned instead as a fallback score. * Else, the precise triphone will be computed and returned. *  * @return the state output probability score in log10. */LOGPROBgms_state(){  LOGPROB gsprob;  if (OP_last_time != OP_time) { /* different frame */    /* set current buffer */    t_fs = fallback_score[OP_time];    /* select state if not yet */    if (!is_selected[OP_time]) {      do_gms();      is_selected[OP_time] = TRUE;    }  }  if ((gsprob = t_fs[state2gs[OP_state_id]]) != LOG_ZERO) {    /* un-selected: return the fallback value */    return(gsprob);  }  /* selected: calculate the real outprob of the state */  return(calc_outprob());}