search_bestfirst_v1.c

説明を見る。

/*
 * 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
 */

#include <julius.h>

#ifndef PASS2_STRICT_IWCD

#undef TCD                      

/**********************************************************************/
/************ 仮説ノードの基本操作                         ************/
/************ Basic functions for hypothesis node handling ************/
/**********************************************************************/

void
free_node(NODE *node)
{
  if (node == NULL) return;
  free(node->g);
  if (ccd_flag) free(node->g_prev);
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  free(node->wordend_frame);
  free(node->wordend_gscore);
#endif
  if (node->prevgraph != NULL && node->prevgraph->saved == FALSE) {
    wordgraph_free(node->prevgraph);
  }
#endif

  free(node);
}

NODE *
cpy_node(NODE *dst, NODE *src)
{
  
  dst->next = src->next;
  dst->prev = src->prev;
  memcpy(dst->g, src->g, sizeof(LOGPROB) * peseqlen);
  memcpy(dst->seq, src->seq, sizeof(WORD_ID) * MAXSEQNUM);
#ifdef CM_SEARCH
#ifdef CM_MULTIPLE_ALPHA
  {
    int w;
    for(w=0;w<src->seqnum;w++) {
      memcpy(dst->cmscore[w], src->cmscore[w], sizeof(LOGPROB) * cm_alpha_num);
    }
  }     
#else
  memcpy(dst->cmscore, src->cmscore, sizeof(LOGPROB) * MAXSEQNUM);
#endif
#endif /* CM_SEARCH */
  dst->seqnum = src->seqnum;
  dst->score = src->score;
  dst->bestt = src->bestt;
  dst->estimated_next_t = src->estimated_next_t;
  dst->endflag = src->endflag;
#ifdef USE_DFA
  dst->state = src->state;
#endif
  dst->tre = src->tre;
  if (ccd_flag) {
    memcpy(dst->g_prev, src->g_prev, sizeof(LOGPROB)*peseqlen);
    dst->last_ph = src->last_ph;
#ifdef MULTIPATH_VERSION
    dst->last_ph_sp_attached = src->last_ph_sp_attached;
#endif
#ifdef USE_NGRAM
    dst->lscore = src->lscore;
#endif
  }
#ifdef USE_NGRAM
  dst->totallscore = src->totallscore;
#endif
#ifdef MULTIPATH_VERSION
  dst->final_g = src->final_g;
#endif
#ifdef VISUALIZE
  dst->popnode = src->popnode;
#endif
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  memcpy(dst->wordend_frame, src->wordend_frame, sizeof(short)*peseqlen);
  memcpy(dst->wordend_gscore, src->wordend_gscore, sizeof(LOGPROB)*peseqlen);
#endif
  dst->prevgraph = src->prevgraph;
  dst->lastcontext = src->lastcontext;
#ifndef GRAPHOUT_PRECISE_BOUNDARY
  dst->tail_g_score = src->tail_g_score;
#endif
#endif
  return(dst);
}

NODE *
newnode()
{
  NODE *tmp;
  int i;

  if ((tmp=(NODE *)mymalloc(sizeof(NODE)))==NULL) {
    j_error("can't malloc\n");
  }
  /*bzero(tmp,sizeof(NODE));*/
  tmp->next=NULL;
  tmp->prev=NULL;
  tmp->g = (LOGPROB *)mymalloc(sizeof(LOGPROB)*peseqlen);
  tmp->last_ph = NULL;
#ifdef MULTIPATH_VERSION
  tmp->last_ph_sp_attached = FALSE;
#endif 
  if (ccd_flag) {
    tmp->g_prev = (LOGPROB *)mymalloc(sizeof(LOGPROB)*peseqlen);
#ifdef USE_NGRAM
    tmp->lscore = LOG_ZERO;
    tmp->totallscore = LOG_ZERO;
#endif
  }
  tmp->endflag = FALSE;
  tmp->seqnum = 0;
  for(i=0;i<peseqlen;i++) {
    tmp->g[i] = LOG_ZERO;
    if (ccd_flag) tmp->g_prev[i] = LOG_ZERO;
  }
#ifdef MULTIPATH_VERSION
  tmp->final_g = LOG_ZERO;
#endif
#ifdef VISUALIZE
  tmp->popnode = NULL;
#endif
  tmp->tre = NULL;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  tmp->wordend_frame = (short *)mymalloc(sizeof(short)*peseqlen);
  tmp->wordend_gscore = (LOGPROB *)mymalloc(sizeof(LOGPROB)*peseqlen);
#endif
  tmp->prevgraph = NULL;
  tmp->lastcontext = NULL;
#endif
  return(tmp);
}


/**********************************************************************/
/************ 前向きトレリス展開と尤度計算              ***************/
/************ Expand trellis and update forward viterbi ***************/
/**********************************************************************/

static LOGPROB *wordtrellis[2]; 
static int tn;                 
static int tl;                 
static LOGPROB *g;              
static HMM_Logical **phmmseq;   
static int phmmlen_max;         
#ifdef MULTIPATH_VERSION
static boolean *has_sp;         
#endif

#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
static short *wend_token_frame[2]; 
static LOGPROB *wend_token_gscore[2]; 
#endif
#endif

void
malloc_wordtrellis()
{
  int maxwn;

  maxwn = winfo->maxwn + 10;
  wordtrellis[0] = (LOGPROB *)mymalloc(sizeof(LOGPROB) * maxwn);
  wordtrellis[1] = (LOGPROB *)mymalloc(sizeof(LOGPROB) * maxwn);

  g = (LOGPROB *)mymalloc(sizeof(LOGPROB) * peseqlen);

  phmmlen_max = winfo->maxwlen + 2;
  phmmseq = (HMM_Logical **)mymalloc(sizeof(HMM_Logical *) * phmmlen_max);
#ifdef MULTIPATH_VERSION
  has_sp = (boolean *)mymalloc(sizeof(boolean) * phmmlen_max);
#endif

#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  wend_token_frame[0] = (short *)mymalloc(sizeof(short) * maxwn);
  wend_token_frame[1] = (short *)mymalloc(sizeof(short) * maxwn);
  wend_token_gscore[0] = (LOGPROB *)mymalloc(sizeof(LOGPROB) * maxwn);
  wend_token_gscore[1] = (LOGPROB *)mymalloc(sizeof(LOGPROB) * maxwn);
#endif
#endif
  
}

void
free_wordtrellis()
{
  free(wordtrellis[0]);
  free(wordtrellis[1]);
  free(g);
  free(phmmseq);
#ifdef MULTIPATH_VERSION
  free(has_sp);
#endif
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  free(wend_token_frame[0]);
  free(wend_token_frame[1]);
  free(wend_token_gscore[0]);
  free(wend_token_gscore[1]);
#endif
#endif
}


/**********************************************************************/
/************ 仮説の前向き尤度計算                  *******************/
/************ Compute forward score of a hypothesis *******************/
/**********************************************************************/

#ifdef MULTIPATH_VERSION

static LOGPROB
get_max_out_arc(HTK_HMM_Trans *tr, int state_num)
{
  LOGPROB max_a;
  int afrom;
  LOGPROB a;
  
  max_a = LOG_ZERO;
  for (afrom = 0; afrom < state_num - 1; afrom++) {
    a = tr->a[afrom][state_num-1];
    if (max_a < a) max_a = a;
  }
  return(max_a);
}

static LOGPROB
max_out_arc(HMM_Logical *l)
{
  return(get_max_out_arc(hmm_logical_trans(l), hmm_logical_state_num(l)));
}

#endif /* MULTIPATH_VERSION */

void
scan_word(NODE *now, HTK_Param *param)
{
  int   i,t, j;
  HMM *whmm;
  A_CELL *ac;
  WORD_ID word;
  LOGPROB tmpmax, tmptmp, score1;
  int startt = 0, endt;
  int wordhmmnum;
#ifdef MULTIPATH_VERSION
  LOGPROB tmpmax_store, store_point_maxarc;
#else
  LOGPROB tmpmax2 = LOG_ZERO;
#endif
  int phmmlen;
  HMM_Logical *ret, *wend;
#ifdef MULTIPATH_VERSION
  int store_point = -1;
#else
  int store_point = 0;
#endif
  int crossword_point = 0;
  boolean back_rescan = FALSE;
  boolean node_exist_p;
  
  /* ----------------------- prepare HMM ----------------------- */

  if (ccd_flag) {
    /* 直前の音素があれば，そこまでさかのぼって scan する */
    /* if there are any last phone, enable backscan */
    if (now->last_ph == NULL) {
      /* initial score: now->g[] */
      /* scan range: phones in now->seq[now->seqnum-1] */
      back_rescan = FALSE;
    } else {
      /* initial score: now->g_prev[] (1-phone before)*/
      /* scan range: phones in now->seq[now->seqnum-1] + now->last_ph */
      back_rescan = TRUE;
    }
  }
#ifdef TCD
  if (now->last_ph != NULL) {
    j_printf("inherited last_ph: %s\n", (now->last_ph)->name);
#ifdef MULTIPATH_VERSION
    if (now->last_ph_sp_attached) j_printf(" (sp attached)\n");
#endif
  } else {
    j_printf("no last_ph inherited\n");
  }
#endif

  /* scan 範囲分のHMMを準備 */
  /* prepare HMM of the scan range */
  word = now->seq[now->seqnum-1];

  if (ccd_flag) {

    if (back_rescan) {
      
      /* scan range: phones in now->seq[now->seqnum-1] + now->last_ph */
      
      phmmlen = winfo->wlen[word] + 1;
      if (phmmlen > phmmlen_max) {
        j_error("short of phmmlen\n");
      }
      for (i=0;i<phmmlen - 2;i++) {
        phmmseq[i] = winfo->wseq[word][i];
#ifdef MULTIPATH_VERSION
        has_sp[i] = FALSE;
#endif
      }
      /* 最終単語と last_ph 間の単語間triphoneを考慮 */
      /* consider cross-word context dependency between the last word and now->last_ph */
      wend = winfo->wseq[word][winfo->wlen[word]-1];
      ret = get_right_context_HMM(wend, now->last_ph->name, hmminfo);
      if (ret == NULL) {        /* triphone not found */
        /* fallback to the original bi/mono-phone */
        /* error if the original is pseudo phone (not explicitly defined
           in hmmdefs/hmmlist) */
        /* exception: word with 1 phone (triphone may exist in the next expansion */
        if (winfo->wlen[word] > 1 && wend->is_pseudo) {
          error_missing_right_triphone(wend, now->last_ph->name);
        }
        phmmseq[phmmlen-2] = wend;
      } else {
        phmmseq[phmmlen-2] = ret;
      }
      ret = get_left_context_HMM(now->last_ph, wend->name, hmminfo);
      if (ret == NULL) {
        /* fallback to the original bi/mono-phone */
        /* error if the original is pseudo phone (not explicitly defined
           in hmmdefs/hmmlist) */
        if (now->last_ph->is_pseudo) {
          error_missing_left_triphone(now->last_ph, wend->name);
        }
        phmmseq[phmmlen-1] = now->last_ph;
      } else {
        phmmseq[phmmlen-1] = ret;
      }

#ifdef MULTIPATH_VERSION
      has_sp[phmmlen-2] = has_sp[phmmlen-1] = FALSE;
      if (enable_iwsp) {
        has_sp[phmmlen-2] = TRUE;
        if (now->last_ph_sp_attached) {
          has_sp[phmmlen-1] = TRUE;
        }
      }
#endif
 
#ifdef TCD
      j_printf("w=");
      for(i=0;i<winfo->wlen[word];i++) {
        j_printf(" %s",(winfo->wseq[word][i])->name);
#ifdef MULTIPATH_VERSION
        if (has_sp[i]) j_printf("(sp)");
#endif
      }
      j_printf(" | %s\n", (now->last_ph)->name);
#ifdef MULTIPATH_VERSION
      if (now->last_ph_sp_attached) j_printf("   (sp)\n");
#endif
      j_printf("scan for:");
      
      for (i=0;i<phmmlen;i++) {
        j_printf(" %s", phmmseq[i]->name);
#ifdef MULTIPATH_VERSION
        if (has_sp[i]) j_printf("(sp)");
#endif
      }
      j_printf("\n");
#endif

      /* 単語HMMを作る */
      /* make word HMM */
      whmm = new_make_word_hmm(hmminfo, phmmseq, phmmlen
#ifdef MULTIPATH_VERSION
                               ,has_sp
#endif
                               );
      
      /* backscan なので，計算前の g[] 初期値は now->g_prev[] を使用 */
      /* As backscan enabled, the initial forward score g[] is set by
         now->g_prev[] */
      for (t=0;t<peseqlen;t++) {
        g[t]=now->g_prev[t];

      }
      
      /* 次段用のg_prevを格納するノード位置を設定 */
      /* set where to store scores as new g_prev[] for the next backscan
         in the HMM */
#ifdef MULTIPATH_VERSION
      store_point = hmm_logical_state_num(phmmseq[0]) - 2;
      store_point_maxarc = max_out_arc(phmmseq[0]);
      if (enable_iwsp && has_sp[0]) {
        store_point += hmm_logical_state_num(hmminfo->sp) - 2;
        if (store_point_maxarc < max_out_arc(hmminfo->sp)) {
          store_point_maxarc = max_out_arc(hmminfo->sp);
        }
      }
#else
      store_point = hmm_logical_state_num(phmmseq[0]) - 2 - 1;
#endif
      /* scan中に直前単語とこの単語をまたぐ場所を設定 */
      /* set where is the connection point of the last word in the HMM */
#ifdef MULTIPATH_VERSION      
      crossword_point = whmm->len - hmm_logical_state_num(phmmseq[phmmlen-1]);
      if (enable_iwsp && has_sp[phmmlen-1]) {
        crossword_point -= hmm_logical_state_num(hmminfo->sp) - 2;
      }
#else
      crossword_point = whmm->len - (hmm_logical_state_num(phmmseq[phmmlen-1]) - 2) - 1;
#endif
      
    } else {                    /* not backscan mode */
      
      /* scan range: phones in now->seq[now->seqnum-1] */
      
#ifdef TCD
      j_printf("scan(org):");
      for (i=0;i<winfo->wlen[word];i++) {
        j_printf(" %s", (winfo->wseq[word][i])->name);
      }
      j_printf("\n");
#endif

#ifdef MULTIPATH_VERSION
      /* 必要ならばショートポーズを挟み込む位置を指定する */
      for(i=0;i<winfo->wlen[word];i++) {
        has_sp[i] = FALSE;
      }
      if (enable_iwsp) {
        has_sp[winfo->wlen[word]-1] = TRUE;
      }
#endif
      
      /* 単語HMMを作る */
      /* make word HMM */
      whmm = new_make_word_hmm(hmminfo, winfo->wseq[word], winfo->wlen[word]
#ifdef MULTIPATH_VERSION
                               , has_sp
#endif
                               );
      
      /* 計算前の g[] 初期値は now->g[] を使用 */
      /* the initial forward score g[] is set by now->g[] */
      for (t=0;t<peseqlen;t++) {
        g[t]=now->g[t];
      }
      
      /* 次段用のg_prevを格納するノード位置を設定 */
      /* set where to store scores as new g_prev[] for the next backscan
         in the HMM */
#ifdef MULTIPATH_VERSION
      store_point = hmm_logical_state_num(winfo->wseq[word][0]) - 2;
      store_point_maxarc = max_out_arc(winfo->wseq[word][0]);
      if (enable_iwsp && has_sp[0]) {
        store_point += hmm_logical_state_num(hmminfo->sp) - 2;
        if (store_point_maxarc < max_out_arc(hmminfo->sp)) {
          store_point_maxarc = max_out_arc(hmminfo->sp);
        }
      }
#else
      store_point = hmm_logical_state_num(winfo->wseq[word][0]) - 2 - 1;
#endif

      /* scan中に直前単語とこの単語をまたぐ場所は，なし */
      /* the connection point of the last word is not exist in the HMM */
      crossword_point = -1;
    }
    
  } else {                      /* ccd_flag == FALSE */

#ifdef MULTIPATH_VERSION
    /* 必要ならばショートポーズを挟み込む位置を指定する */
    for(i=0;i<winfo->wlen[word];i++) {
      has_sp[i] = FALSE;
    }
    if (enable_iwsp) {
      has_sp[winfo->wlen[word]-1] = TRUE;
    }
#endif

    /* 音素環境非依存の場合は単純に最終単語分の HMM を作成 */
    /* for monophone: simple make HMM for the last word */
    whmm = new_make_word_hmm(hmminfo, winfo->wseq[word], winfo->wlen[word]
#ifdef MULTIPATH_VERSION
                             , has_sp
#endif
                             );

    /* 計算前の g[] 初期値は now->g[] を使用 */
    /* the initial forward score g[] is set by now->g[] */
    for (t=0;t<peseqlen;t++) {
      g[t]=now->g[t];
    }
    
  }

#ifdef TCD
  j_printf("whmm len      = %d\n",whmm->len);
  j_printf("crossword_point = %d\n", crossword_point);
  j_printf("g[] store point = %d\n", store_point);
#endif

  wordhmmnum = whmm->len;
  if (wordhmmnum >= winfo->maxwn + 10) {
    j_error("scan_word: word too long\n");
  }

#ifdef GRAPHOUT
#ifndef GRAPHOUT_PRECISE_BOUNDARY
  if (ccd_flag) {
    now->tail_g_score = now->g[now->bestt];
  }
#endif
#endif

  /* ----------------------- do scan ----------------------- */
  
  /* scan開始点を検索 -> starttへ*/
  /* search for the start frame -> set to startt */
  for(t = peseqlen-1; t >=0 ; t--) {
    if (
#ifdef SCAN_BEAM
        g[t] > framemaxscore[t] - scan_beam_thres &&
#endif
        g[t] > LOG_ZERO) {
      break;
    }
  }
  if (t < 0) {                  /* no node has score > LOG_ZERO */
    for(t=0;t<peseqlen;t++) {
      if (ccd_flag) now->g_prev[t] = LOG_ZERO;
      now->g[t] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
      now->wordend_frame[t] = -1;
      now->wordend_gscore[t] = LOG_ZERO;
#endif
#endif
    }
    goto end_of_scan;
  }
  startt = t;
  
  /* clear [startt+1..peseqlen-1] */
  for(t=peseqlen-1;t>startt;t--) {
    if (ccd_flag) now->g_prev[t] = LOG_ZERO;
    now->g[t] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
    now->wordend_frame[t] = -1;
    now->wordend_gscore[t] = LOG_ZERO;
#endif
#endif
  }

  /* バッファポインタ初期化 */
  tn = 0; tl = 1;

#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  for(i=0;i<wordhmmnum;i++) {
    wend_token_frame[tn][i] = -1;
    wend_token_gscore[tn][i] = LOG_ZERO;
  }
#endif
#endif
  
#ifndef MULTIPATH_VERSION
  /* Below initialization is not needed on multipath version, since
     the actual viterbi will begin at frame 0 in multipath mode in main loop */
  
  /* 時間 [startt] 上の値を初期化 */
  /* initialize scores on frame [startt] */
  for(i=0;i<wordhmmnum-1;i++) wordtrellis[tn][i] = LOG_ZERO;
  wordtrellis[tn][wordhmmnum-1] = g[startt] + outprob(startt, &(whmm->state[wordhmmnum-1]), param);
  if (ccd_flag) {
    now->g_prev[startt] = wordtrellis[tn][store_point];
  }
  now->g[startt] = wordtrellis[tn][0];

#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  if (ccd_flag) {
    if (back_rescan) {
      if (wordhmmnum-1 == crossword_point) {
        wend_token_frame[tn][wordhmmnum-1] = startt;
        wend_token_gscore[tn][wordhmmnum-1] = g[startt];
      } else {
        wend_token_frame[tn][wordhmmnum-1] = -1;
        wend_token_gscore[tn][wordhmmnum-1] = LOG_ZERO;
      }
    } else {
      wend_token_frame[tn][wordhmmnum-1] = startt;
      wend_token_gscore[tn][wordhmmnum-1] = g[startt];
    }
  } else {
    wend_token_frame[tn][wordhmmnum-1] = startt;
    wend_token_gscore[tn][wordhmmnum-1] = g[startt];
  }
  now->wordend_frame[startt] = wend_token_frame[tn][0];
  now->wordend_gscore[startt] = wend_token_gscore[tn][0];
#endif
#endif

#endif /* ~MULTIPATH_VERSION */
  
  endt = startt;

  /* メインループ: startt から始まり 0 に向かって Viterbi 計算 */
  /* main loop: start from [startt], and compute Viterbi toward [0] */
  for(t=
#ifdef MULTIPATH_VERSION
        startt
#else
        startt-1
#endif
        ;t>=0;t--) {
    
    /* wordtrellisのワークエリアをスワップ */
    i = tn; tn = tl; tl = i;
    
    node_exist_p = FALSE;       /* TRUE if there is at least 1 survived node in this frame */

#ifdef MULTIPATH_VERSION

    /* 端のノード [t][wordhmmnum-1]は g[] を参照する */
    /* the edge node [t][wordhmmnum-1] is equal to g[] */
  
    /* ノード [t][wordhmmnum-2..0] についてトレリスを計算 */
    /* expand trellis for node [t][wordhmmnum-2..0] */
    tmpmax_store = LOG_ZERO;
    
#else  /* ~MULTIPATH_VERSION */
    
    /* 端のノード [t][wordhmmnum-1]は，内部遷移 か g[]の高い方になる */
    /* the edge node [t][wordhmmnum-1] is either internal transitin or g[] */
    tmptmp = LOG_ZERO;
    for (ac=whmm->state[wordhmmnum-1].ac;ac;ac=ac->next) {
      score1 = wordtrellis[tl][ac->arc] + ac->a;
      if (tmptmp < score1) {
        j = ac->arc;
        tmptmp = score1;
      }
    }
    if (g[t] > tmptmp) {
      tmpmax = g[t];
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
      if (!back_rescan || wordhmmnum-1 == crossword_point) {
        wend_token_frame[tn][wordhmmnum-1] = t;
        wend_token_gscore[tn][wordhmmnum-1] = g[t];
      } else {
        wend_token_frame[tn][wordhmmnum-1] = wend_token_frame[tl][j];
        wend_token_gscore[tn][wordhmmnum-1] = wend_token_gscore[tl][j];
      }
#endif
#endif
    } else {
      tmpmax = tmptmp;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
      wend_token_frame[tn][wordhmmnum-1] = wend_token_frame[tl][j];
      wend_token_gscore[tn][wordhmmnum-1] = wend_token_gscore[tl][j];
#endif
#endif
    }

    /* 端のノードのスコアエンベロープチェック: 一定幅外なら落とす */
    /* check if the edge node is within score envelope */
    if (
#ifdef SCAN_BEAM
        tmpmax <= framemaxscore[t] - scan_beam_thres ||
#endif
        tmpmax <= LOG_ZERO
        ) {
      wordtrellis[tn][wordhmmnum-1] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
      wend_token_frame[tn][wordhmmnum-1] = -1;
      wend_token_gscore[tn][wordhmmnum-1] = LOG_ZERO;
#endif
#endif
    } else {
      node_exist_p = TRUE;
      wordtrellis[tn][wordhmmnum-1] = tmpmax + outprob(t, &(whmm->state[wordhmmnum-1]), param);
    }

#endif /* MULTIPATH_VERSION  */

    /* ノード [t][wordhmmnum-2..0] についてトレリスを計算 */
    /* expand trellis for node [t][wordhmmnum-2..0] */
    for(i=wordhmmnum-2;i>=0;i--) {

      if (ccd_flag) {

        /* 最尤パスと最尤スコア tmpmax を見つける */
        /* tmpmax2 は次回用 g_prev[] のための最大値(自己遷移を除いた最大値) */
        /* find most likely path and the max score 'tmpmax' */
        /* 'tmpmax2' is max score excluding self transition, for next g_prev[] */
#ifndef MULTIPATH_VERSION
        if (i == store_point) {
          tmpmax2 = LOG_ZERO;
        }
#endif
        tmpmax = LOG_ZERO;
        for (ac=whmm->state[i].ac;ac;ac=ac->next) {
#ifdef MULTIPATH_VERSION
          if (ac->arc == wordhmmnum-1) score1 = g[t];
          else if (t + 1 > startt) score1 = LOG_ZERO;
          else score1 = wordtrellis[tl][ac->arc];
          score1 += ac->a;
#else
          score1 = wordtrellis[tl][ac->arc] + ac->a;
#endif
          if (i <= crossword_point && ac->arc > crossword_point) {
            /* これは単語を越える遷移 (backscan 実行時) */
            /* this is a transition across word (when backscan is enabled) */
#ifdef USE_NGRAM
            score1 += now->lscore; /* add N-gram LM score */
#else
            score1 += penalty2; /* add DFA insertion penalty */
#endif
          }
#ifdef MULTIPATH_VERSION
          if (i <= store_point && ac->arc > store_point) {
            if (tmpmax_store < score1) tmpmax_store = score1;
          }
#else
          if (i == store_point && i != ac->arc) {
            if (tmpmax2 < score1) tmpmax2 = score1;
          }
#endif
          if (tmpmax < score1) {
            tmpmax = score1;
            j = ac->arc;
          }
        }

        /* スコアエンベロープチェック: 一定幅外なら落とす */
        /* check if score of this node is within the score envelope */
        if (
#ifdef SCAN_BEAM
            tmpmax <= framemaxscore[t] - scan_beam_thres ||
#endif
            tmpmax <= LOG_ZERO
            ) {  /* invalid node */
          wordtrellis[tn][i] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
          wend_token_frame[tn][i] = -1;
          wend_token_gscore[tn][i] = LOG_ZERO;
#endif
#endif
#ifndef MULTIPATH_VERSION
          if (i == store_point) now->g_prev[t] = LOG_ZERO;
#endif
        } else { /* survived node */
#ifndef MULTIPATH_VERSION
          if (i == store_point) now->g_prev[t] = tmpmax2;
#endif
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
          if (
#ifdef MULTIPATH_VERSION
              (back_rescan && i <= crossword_point && j > crossword_point)
              || j == wordhmmnum-1
#else
              i <= crossword_point && j > crossword_point
#endif
              ) {
            wend_token_frame[tn][i] = t;
            wend_token_gscore[tn][i] = tmpmax;
          } else {
            wend_token_frame[tn][i] = wend_token_frame[tl][j];
            wend_token_gscore[tn][i] = wend_token_gscore[tl][j];
          }
#endif
#endif
          node_exist_p = TRUE;  /* at least one node survive in this frame */
#ifdef MULTIPATH_VERSION
          wordtrellis[tn][i] = tmpmax;
          if (i > 0) {
            /* compute output probability */
            wordtrellis[tn][i] += outprob(t, &(whmm->state[i]), param);
          }
#else
          /* compute output probability */
          tmptmp = outprob(t, &(whmm->state[i]), param);
          /* score of node [t][i] has been determined here */
          wordtrellis[tn][i] = tmpmax + tmptmp;
#endif
        }
        
      } else {                  /* not triphone */

        /* backscan 無し: store_point, crossword_point は無関係 */
        /* no backscan: store_point, crossword_point ignored */
        tmpmax = LOG_ZERO;
        for (ac=whmm->state[i].ac;ac;ac=ac->next) {
#ifdef MULTIPATH_VERSION
          if (ac->arc == wordhmmnum-1) score1 = g[t];
          else if (t + 1 > startt) score1 = LOG_ZERO;
          else score1 = wordtrellis[tl][ac->arc];
          score1 += ac->a;
#else
          score1 = wordtrellis[tl][ac->arc] + ac->a;
#endif
          if (tmpmax < score1) {
            tmpmax = score1;
            j = ac->arc;
          }
        }

        /* スコアエンベロープチェック: 一定幅外なら落とす */
        /* check if score of this node is within the score envelope */
        if (
#ifdef SCAN_BEAM
            tmpmax <= framemaxscore[t] - scan_beam_thres ||
#endif
            tmpmax <= LOG_ZERO
            ) {
          /* invalid node */
          wordtrellis[tn][i] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
          wend_token_frame[tn][i] = -1;
          wend_token_gscore[tn][i] = LOG_ZERO;
#endif
#endif
        } else {
          /* survived node */
          node_exist_p = TRUE;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
#ifdef MULTIPATH_VERSION
          if (j == wordhmmnum-1) {
            wend_token_frame[tn][i] = t;
            wend_token_gscore[tn][i] = tmpmax;
          } else {
            wend_token_frame[tn][i] = wend_token_frame[tl][j];
            wend_token_gscore[tn][i] = wend_token_gscore[tl][j];
          }
#else
          wend_token_frame[tn][i] = wend_token_frame[tl][j];
          wend_token_gscore[tn][i] = wend_token_gscore[tl][j];
#endif
#endif
#endif
          /* score of node [t][i] has been determined here */
#ifdef MULTIPATH_VERSION
          wordtrellis[tn][i] = tmpmax;
          if (i > 0) {
            wordtrellis[tn][i] += outprob(t, &(whmm->state[i]), param);
          } 
#else
          wordtrellis[tn][i] = tmpmax + outprob(t, &(whmm->state[i]), param);
#endif
        }
        
      }
    } /* end of node loop */

    /* 時間 t のViterbi計算終了．前向きスコアはscanした単語の始端 */
    /* Viterbi end for frame [t].  the forward score is the score of word
       beginning scanned */
    now->g[t] = wordtrellis[tn][0];
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
    now->wordend_frame[t] = wend_token_frame[tn][0];
    now->wordend_gscore[t] = wend_token_gscore[tn][0];
#endif
#endif

#ifdef MULTIPATH_VERSION
    /* triphone 時, 次段のために store_point のデータをg_prevに保存 */
    /* store the scores crossing the store_point to g_prev, for next scan */
    if (ccd_flag) {
      /* the max arc crossing the store_point always selected as tmpmax_score */ 
      tmpmax_store -= store_point_maxarc;
      if (tmpmax_store < LOG_ZERO) tmpmax_store = LOG_ZERO;
      now->g_prev[t] = tmpmax_store;
    }
#endif

    /* store the number of last computed frame */
    if (node_exist_p) endt = t;
    
    /* scanした単語の第１パスでの始端時刻より先まで t が進んでおり，かつ
       この t においてスコアエンベロープによって生き残ったノードが一つも
       無かったならば,このフレームで計算を打ち切りそれ以上先([0..t-1])は
       計算しない */
    /* if frame 't' already reached the beginning frame of scanned word
       in 1st pass and no node was survived in this frame (all nodes pruned
       by score envelope), terminate computation at this frame and
       do not computer further frame ([0..t-1]). */
    if (t < now->estimated_next_t && (!node_exist_p)) {
      /* clear the rest scores */
      for (i=t-1;i>=0;i--) {
        now->g[i] = LOG_ZERO;
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
        now->wordend_frame[i] = -1;
        now->wordend_gscore[i] = LOG_ZERO;
#endif
#endif
        if (ccd_flag) now->g_prev[i] = LOG_ZERO;
      }
      /* terminate loop */
      break;
    }
    
  } /* end of time loop */
  
  if (debug2_flag) j_printf("scanned: [%3d-%3d]\n", endt, startt);

 end_of_scan:

#ifdef MULTIPATH_VERSION
  /* 前向きスコアの最終値を計算 (状態 0 から時間 0 への遷移) */
  /* compute the total forward score (transition from state 0 to frame 0 */
  if (endt == 0) {
    tmpmax = LOG_ZERO;
    for(ac=whmm->state[0].ac;ac;ac=ac->next) {
      score1 = wordtrellis[tn][ac->arc] + ac->a;
      if (tmpmax < score1) tmpmax = score1;
    }
    now->final_g = score1;
  } else {
    now->final_g = LOG_ZERO;
  }
#endif
  
  /* 次回 backscan のための情報格納 */
  /* store data for next backscan */
  if (ccd_flag) {
    if (store_point ==
#ifdef MULTIPATH_VERSION
        wordhmmnum - 2
#else
        wordhmmnum - 1
#endif
        ) {
      /* last_ph無し，かつ単語の音素長=1の場合、次回の scan_word() で
         単語全体がもう一度再計算される．この場合,
         g_prev は，このscan_wordを開始する前のスコアを入れておく必要がある */
      /* if there was no 'last_ph' and the scanned word consists of only
         1 phone, the whole word should be re-computed in the future scan_word().
         So the next 'g_prev[]' should be the initial forward scores
         before we begin Viterbi (= g[t]). */
      for (t = startt; t>=0; t--) {
        now->g_prev[t] = g[t];
      }
    }
#ifdef GRAPHOUT
#ifndef GRAPHOUT_PRECISE_BOUNDARY
    if (now->tail_g_score != LOG_ZERO) {
      if (now->prevgraph != NULL) {
        (now->prevgraph)->leftscore = now->tail_g_score;
      }
    }
#endif
#endif
    /* 次回のために now->last_ph を更新 */
    /* update 'now->last_ph' for future scan_word() */
    if (back_rescan) {
      now->last_ph = phmmseq[0];
    } else {
      now->last_ph = winfo->wseq[word][0];
    }
#ifdef MULTIPATH_VERSION
    now->last_ph_sp_attached = has_sp[0];
#endif
  }

#ifndef MULTIPATH_VERSION
#ifdef GRAPHOUT
#ifdef GRAPHOUT_PRECISE_BOUNDARY
  /* 次回の next_word 用に境界情報を調整 */
  /* proceed word boundary for one step for next_word */
  now->wordend_frame[peseqlen-1] = now->wordend_frame[0];
  now->wordend_gscore[peseqlen-1] = now->wordend_gscore[0];
  for (t=0;t<peseqlen-1;t++) {
    now->wordend_frame[t] = now->wordend_frame[t+1];
    now->wordend_gscore[t] = now->wordend_gscore[t+1];
  }
#endif
#endif
#endif /* MULTIPATH_VERSION */

  /* free work area */
  free_hmm(whmm);
#ifdef TCD
#ifdef MULTIPATH_VERSION
  if (ccd_flag) {
    j_printf("last_ph = %s", (now->last_ph)->name);
    if (now->last_ph_sp_attached) j_printf(" (sp attached)");
    j_printf("\n");
  }
#else
  j_printf("last_ph = %s\n", (now->last_ph)->name);
#endif
#endif
}


/**************************************************************************/
/*** 新仮説の展開とヒューリスティックを繋いだ全体スコアを計算           ***/
/*** Expand new hypothesis and compute the total score (with heuristic) ***/
/**************************************************************************/

void
next_word(NODE *now, NODE *new, NEXTWORD *nword, HTK_Param *param, BACKTRELLIS *backtrellis)
{
  int   t;
  HMM_Logical *newphone;
  int lastword;
  int   i;
  LOGPROB tmpp;
#ifndef MULTIPATH_VERSION
  LOGPROB a_value;
#endif
  int   startt;
  int word;
#ifndef WORD_GRAPH
  LOGPROB totalscore;
  TRELLIS_ATOM *tre;
#endif

  new->score = LOG_ZERO;

  word = nword->id;
  lastword=now->seq[now->seqnum-1];

  /* 単語並び、DFA状態番号、言語スコアを継承・更新 */
  /* inherit and update word sequence, DFA state and total LM score */
  for (i=0;i< now->seqnum;i++){ 
    new->seq[i] = now->seq[i];
#ifdef CM_SEARCH
#ifdef CM_MULTIPLE_ALPHA
    memcpy(new->cmscore[i], now->cmscore[i], sizeof(LOGPROB) * cm_alpha_num);
#else
    new->cmscore[i] = now->cmscore[i];
#endif
#endif /* CM_SEARCH */
  }
  new->seq[i] = word;
  new->seqnum = now->seqnum+1;
#ifdef USE_DFA
  new->state = nword->next_state;
#endif
#ifdef USE_NGRAM
  new->totallscore = now->totallscore + nword->lscore;
#endif  
#ifdef MULTIPATH_VERSION
  new->final_g = now->final_g;
#endif
  
  if (ccd_flag) {
    
    /* 展開単語の接続点の音素HMMをnewphoneにセットする．
       元仮説 now との単語間の音素環境依存性を考慮する */
    /* set the triphone at the connection point to 'newphone', considering
       cross-word context dependency to 'now' */
    newphone = get_right_context_HMM(winfo->wseq[word][winfo->wlen[word]-1], now->last_ph->name, hmminfo);
    if (newphone == NULL) {     /* triphone not found */
      /* fallback to the original bi/mono-phone */
      /* error if the original is pseudo phone (not explicitly defined
         in hmmdefs/hmmlist) */
      /* exception: word with 1 phone (triphone may exist in the next expansion */
      if (winfo->wlen[word] > 1 && winfo->wseq[word][winfo->wlen[word]-1]->is_pseudo){
        error_missing_right_triphone(winfo->wseq[word][winfo->wlen[word]-1], now->last_ph->name);
      }
      newphone = winfo->wseq[word][winfo->wlen[word]-1];
    }
    
    /* 元仮説をscanした時の末端音素HMM -> 新仮説の直前音素HMM */
    /* inherit last_ph */
    new->last_ph = now->last_ph;
#ifdef MULTIPATH_VERSION
    new->last_ph_sp_attached = now->last_ph_sp_attached;
#endif
    
    /* backscan用接続ポイントのスコア g_prev[] をコピー */
    /* copy g_prev[] that are scores at backscan connection point */
    for (t=0;t<peseqlen;t++) {
      new->g_prev[t] = now->g_prev[t];
    }
    
  } else {                      /* not triphone */
    
    /* 展開単語の接続(=終端)の音素HMMをnewphoneにセット */
    /* set the phone at the connection point to 'newphone' */
    newphone = winfo->wseq[word][winfo->wlen[word]-1];
  }

#ifdef USE_NGRAM
  /* set current LM score */
  new->lscore = nword->lscore;
#endif

#ifndef MULTIPATH_VERSION
  /* a_value: 接続点の遷移確率 */
  /* a_value: transition probability of connection point */
  i = hmm_logical_state_num(newphone);
  a_value = (hmm_logical_trans(newphone))->a[i-2][i-1];
#endif

  /***************************************************************************/
  /* 前向き(第２パス),後ろ向き(第１パス)トレリスを接続し最尤接続点を見つける */
  /* connect forward/backward trellis to look for the best connection time   */
  /***************************************************************************/

#ifdef MULTIPATH_VERSION
  startt = peseqlen-1;
#else
  startt = peseqlen-2;
  new->g[startt+1] = LOG_ZERO;
#endif

#ifdef WORD_GRAPH
  /*-----------------------------------------------------------------*/
  /* 単語グラフモードでは同じフレームの同じ単語でも直前単語毎にスコ
     アが違う．bestt は 固定 */
  /* there are several trellis word with the same word ID in the same
     frame, with different word context in WORD_GRAPH mode.  And the
     best t is fixed (no re-esimation) */
  /*-----------------------------------------------------------------*/

  /* update new->g[t] */
  for(t=startt;t>=0;t--) {
    new->g[t] =
#ifdef MULTIPATH_VERSION
      now->g[t]
#else
      now->g[t+1] + a_value
#endif
#ifdef USE_NGRAM
      + nword->lscore
#else
      + penalty2
#endif
      ;
  }
  
  /* 最尤接続点は, 最後に参照したTRELLIS_ATOMの終端に固定 */
  /* the best connection point is fixed to the end time of last trellis word (no re-alignment */
  new->bestt = (nword->tre)->endtime;
  /* 次回の展開単語決定のための推定始端時間は，上記の始端 */
  /* the estimated next beginning frame for the next word expansion
     corresponds to the endtime above (this is also fixed) */
  new->estimated_next_t = (nword->tre)->begintime - 1;

  /* 仮説全体のスコアを計算 */
#ifdef MULTIPATH_VERSION
  new->score = new->g[new->bestt] + (nword->tre)->backscore;
#else
  /* 接続部の状態の出力確率を加算 */
  /* add output prob of connection state */
  if (newphone->is_pseudo) {
    tmpp = outprob_cd(new->bestt, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
  } else {
    tmpp = outprob_state(new->bestt, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
  }
  new->score = new->g[new->bestt] + (nword->tre)->backscore + tmpp;
#endif
  
  /* 展開単語のトレリス上の情報を伝搬 */
  new->tre  =  nword->tre;
  
#else  /* not WORD_GRAPH */

  /*-----------------------------------------------------------------*/
  /* 単語トレリスを探して, 次単語の最尤接続点を発見する */
  /* determine the best connection time of the new word, seeking the word
     trellis */
  /*-----------------------------------------------------------------*/

  /* update new->g[t] */
  for(t=startt;t>=0;t--) {
    new->g[t] =
#ifdef MULTIPATH_VERSION
      now->g[t]
#else
      now->g[t+1] + a_value
#endif
#ifdef USE_NGRAM
      + nword->lscore
#else
      + penalty2
#endif
      ;
  }

#ifdef USE_DFA
  if (!looktrellis_flag) {
    /* すべてのフレームにわたって最尤を探す */
    /* search for best trellis word throughout all frame */
    for(t = startt; t >= 0; t--) {
      tre = bt_binsearch_atom(backtrellis, t, (WORD_ID) word);
      if (tre == NULL) continue;
#ifdef MULTIPATH_VERSION
      totalscore = new->g[t] + tre->backscore;
#else
      if (newphone->is_pseudo) {
        tmpp = outprob_cd(t, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
      } else {
        tmpp = outprob_state(t, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
      }
      totalscore = new->g[t] + tre->backscore + tmpp;
#endif
      if (new->score < totalscore) {
        new->score = totalscore;
        new->bestt = t;
        new->estimated_next_t = tre->begintime - 1;
        new->tre  =  tre;
      }
    }
  } else {
#endif /* USE_DFA */
      
  /* この展開単語のトレリス上の終端時間の前後のみスキャンする
     前後に連続して存在するフレームについてのみ計算 */
  /* search for best trellis word only around the estimated time */
  /* 1. search forward */
  for(t = (nword->tre)->endtime; t >= 0; t--) {
    tre = bt_binsearch_atom(backtrellis, t, (WORD_ID) word);
    if (tre == NULL) break;     /* go to 2 if the trellis word disappear */
#ifdef MULTIPATH_VERSION
    totalscore = new->g[t] + tre->backscore;
#else
    if (newphone->is_pseudo) {
      tmpp = outprob_cd(t, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
    } else {
      tmpp = outprob_state(t, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
    }
    totalscore = new->g[t] + tre->backscore + tmpp;
#endif
    if (new->score < totalscore) {
      new->score = totalscore;
      new->bestt = t;
      new->estimated_next_t = tre->begintime - 1;
      new->tre = tre;
    }
  }
  /* 2. search backward */
  for(t = (nword->tre)->endtime + 1; t <= startt; t++) {
    tre = bt_binsearch_atom(backtrellis, t, (WORD_ID) word);
    if (tre == NULL) break;     /* end if the trellis word disapper */
#ifdef MULTIPATH_VERSION
    totalscore = new->g[t] + tre->backscore;
#else
    if (newphone->is_pseudo) {
      tmpp = outprob_cd(t, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
    } else {
      tmpp = outprob_state(t, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
    }
    totalscore = new->g[t] + tre->backscore + tmpp;
#endif
    if (new->score < totalscore) {
      new->score = totalscore;
      new->bestt = t;
      new->estimated_next_t = tre->begintime - 1;
      new->tre = tre;
    }
  }

#ifdef USE_DFA
  }
#endif

#endif /* WORD_GRAPH */

}

/**********************************************************************/
/********** 初期仮説の生成                 ****************************/
/********** Generate an initial hypothesis ****************************/
/**********************************************************************/

void
start_word(NODE *new, NEXTWORD *nword, HTK_Param *param, BACKTRELLIS *backtrellis)
{
  HMM_Logical *newphone;
  WORD_ID word;
  LOGPROB tmpp;
#ifndef WORD_GRAPH
  int t;
  TRELLIS_ATOM *tre = NULL;
#endif

  /* initialize data */
  word = nword->id;
  new->score = LOG_ZERO;
  new->seqnum = 1;
  new->seq[0] = word;

#ifdef USE_DFA
  new->state = nword->next_state;
#endif
#ifdef USE_NGRAM
  new->totallscore = nword->lscore;
#endif  

  /* cross-word triphone handling is not needed on startup */
  newphone = winfo->wseq[word][winfo->wlen[word]-1];
  if (ccd_flag) {
    new->last_ph = NULL;
#ifdef MULTIPATH_VERSION
    new->last_ph_sp_attached = FALSE;
#endif
  }
#ifdef USE_NGRAM
  new->lscore = nword->lscore;
#endif
  
#ifdef USE_NGRAM
  new->g[peseqlen-1] = nword->lscore;
#else  /* USE_DFA */
  new->g[peseqlen-1] = 0;
#endif
  
#ifdef WORD_GRAPH
#ifdef MULTIPATH_VERSION
  new->score = new->g[peseqlen-1] + (nword->tre)->backscore;
#else
  if (newphone->is_pseudo) {
    tmpp = outprob_cd(peseqlen-1, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
  } else {
    tmpp = outprob_state(peseqlen-1, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
  }
  new->score = new->g[peseqlen-1] + (nword->tre)->backscore + tmpp;
#endif
  new->tre  =  nword->tre;
  new->bestt = peseqlen-1;
  new->estimated_next_t = (nword->tre)->begintime - 1;
  
#else

  for (t=peseqlen-1; t>=0; t--) {
    tre = bt_binsearch_atom(backtrellis, t, word);
    if (tre != NULL) {
#ifdef GRAPHOUT
      new->bestt = peseqlen-1;
#else
      new->bestt = t;
#endif
#ifdef MULTIPATH_VERSION
      new->score = new->g[peseqlen-1] + tre->backscore;
#else
      if (newphone->is_pseudo) {
        tmpp = outprob_cd(peseqlen-1, &(newphone->body.pseudo->stateset[newphone->body.pseudo->state_num-2]), param);
      } else {
        tmpp = outprob_state(peseqlen-1, newphone->body.defined->s[newphone->body.defined->state_num-2], param);
      }
      new->score = new->g[peseqlen-1] + tre->backscore + tmpp;
#endif
      new->estimated_next_t = tre->begintime - 1;
      new->tre = tre;
      break;
    }
  }
  if (tre == NULL) {            /* no word in backtrellis */
    new->score = LOG_ZERO;
  }
#endif /* WORD_GRAPH */
}


void
last_next_word(NODE *now, NODE *new, HTK_Param *param)
{
  cpy_node(new, now);
  /* 最終スコアを設定 */
  /* update the final score */
#ifdef MULTIPATH_VERSION
  new->score = now->final_g;
#else
  new->score = now->g[0];
#endif
}


#endif /* PASS2_STRICT_IWCD */

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