backtrellis.c

来自「julius version 4.12.about sound recognit」· C语言 代码 · 共 589 行 · 第 1/2 页

/**
 * @file   backtrellis.c
 * 
 * <JA>
 * @brief  帽胳トレリスの瘦赂ˇ徊救
 *
 * 妈1パスの冯蔡を帽胳トレリスとして瘦赂し·妈2パスで徊救するための簇眶凡
 * です. Julius では·妈１パスで玫瑚面に姜眉が栏き荒っていた帽胳は链て·
 * その幌姜眉フレ〖ム·幌眉からの芜姥锑刨および帽胳旺悟とともに
 * 瘦赂され·妈２パスでその礁圭の面から浩玫瑚が乖われます. 
 * この妈１パスでフレ〖ムごとに荒される帽胳攫鼠のことを≈トレリス帽胳∽·
 * トレリス帽胳の礁圭链挛を≈帽胳トレリス∽と钙びます. 
 *
 * トレリス帽胳は·妈１パスの千急面に称フレ〖ムごとに瘦赂されます. 
 * 妈１パス姜位稿·トレリス链挛の腊妨ˇ浩芹弥とフレ〖ムごとのインデックス
 * を侯喇します. 
 *
 * 妈２パスでは·この帽胳トレリスを徊救して
 * 称箕粗∈掐蜗フレ〖ム∷における鸥倡材墙な簿棱のリストを评るとともに·
 * その妈１パスでの(稿ろ羹きの)芜姥锑刨を·妈２パスにおける簿棱の踏鸥倡婶尸の
 * 夸年スコアとして脱います. このしくみから·帽胳トレリスは≈バックトレリス∽
 * とも钙ばれています. 
 * </JA>
 * 
 * <EN>
 * @brief  Word trellis operations
 *
 * Functions to store the result of the 1st pass as "word trellis",
 * and functions to access them from the 2nd pass are defined in this
 * file.  On the 1st pass of Julius, all the promising words whose
 * word end has been survived at the 1st pass will be stored as "word
 * trellis", which consists of surviving words: word boundary,
 * accumulated score and word history.
 *
 * The trellis word will be stored per frame at the 1st pass.  After
 * the 1st pass ended, the word trellis will be re-organized and
 * indexed by frame to prepare for access at the 2nd pass.
 *
 * In the 2nd pass of reverse stack decoding, this word trellis will be
 * used to constrain the word hypothesis, and also used to estimate
 * the score of unseen area by the obtained backward scores in the 1st pass.
 * Thus the word trellis information is also called as "back trellis" in
 * Julius.
 * </EN>
 * 
 * @author Akinobu LEE
 * @date   Tue Feb 22 15:40:01 2005
 *
 * $Revision: 1.2 $
 * 
 */
/*
 * 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 <julius/julius.h>

/** 
 * <JA>
 * 帽胳トレリスを瘦积する 帽胳トレリス 菇陇挛を介袋步する(弹瓢箕に1搀だけ悸乖)
 * 
 * @param bt [in] 介袋步する 帽胳トレリス 菇陇挛へのポインタ 
 * </JA>
 * <EN>
 * Initialize backtrellis that will hold the whole word trellis
 * (called once on startup).
 * 
 * @param bt [in] pointer to the backtrellis structure to initialize
 * </EN>
 *
 * @callergraph
 * @callgraph
 * 
 */
void
bt_init(BACKTRELLIS *bt)
{
  bt->num  = NULL;
  bt->rw   = NULL;
  bt->list = NULL;
  bt->root = NULL;
}

/** 
 * <JA>
 * 肌搀の千急脱に 帽胳トレリス 菇陇挛を洁洒する (千急倡幌箕ごとに悸乖). 
 * 
 * @param bt [in] 滦据とする帽胳トレリス菇陇挛へのポインタ
 * </JA>
 * <EN>
 * Prepare backtrellis for the next input (called at beginning of each
 * speech segment).
 * 
 * @param bt [in] pointer to the word trellis structure
 * </EN>
 * @callergraph
 * @callgraph
 * 
 */
void
bt_prepare(BACKTRELLIS *bt)
{
  /* free previously allocated data */
  mybfree2(&(bt->root));

  /* reset entry point */
  bt->num = NULL;
  bt->rw = NULL;
  bt->list = NULL;
  bt->root = NULL;
}  

/** 
 * <EN>
 * Free memories of backtrellis.
 * </EN>
 * <JA>
 * 帽胳トレリスのメモリを倡庶する. 
 * </JA>
 * 
 * @param bt [out] pointer to the word trellis structure.
 *
 * @callergraph
 * @callgraph
 * 
 */
void
bt_free(BACKTRELLIS *bt)
{
  if (bt->root) mybfree2(&(bt->root));
  free(bt);
}

/** 
 * <EN>
 * Allocate a new trellis word atom.
 * </EN>
 * <JA>
 * トレリス帽胳を糠たに充り烧ける. 
 * </JA>
 * 
 * @param bt [out] pointer to the word trellis structure.
 *
 * @return pointer to the newly allocated trellis word.
 *
 * @callergraph
 * @callgraph
 * 
 */
TRELLIS_ATOM *
bt_new(BACKTRELLIS *bt)
{
  TRELLIS_ATOM *new;

  new = (TRELLIS_ATOM *)mybmalloc2(sizeof(TRELLIS_ATOM), &(bt->root));
  return new;
}



/** 
 * <JA>
 * 妈1パスで叫附したトレリス帽胳∈帽胳姜眉のトレリス攫鼠∷を呈羌する. 
 *
 * ここでは呈羌だけ乖い·妈1パス姜位稿に bt_relocate_rw() で
 * フレ〖ム界に浩芹弥する. 
 * 
 * @param bt [i/o] トレリス帽胳を呈羌するバックトレリス菇陇挛
 * @param tatom [in] 叫附したトレリス帽胳へのポインタ
 * </JA>
 * <EN>
 * Store a trellis word generated on the 1st pass for the 2nd pass.
 *
 * This function just store the new atom into backtrellis.
 * They will be re-located per frame after 1st pass for quick access
 * in the 2nd pass.
 * 
 * @param bt [i/o] backtrellis structure to store the trellis word
 * @param tatom [in] the trellis word to be stored
 * </EN>
 *
 * @callergraph
 * @callgraph
 * 
 */
void
bt_store(BACKTRELLIS *bt, TRELLIS_ATOM *tatom)
{
#ifdef WORD_GRAPH
  tatom->within_context = FALSE;
  tatom->within_wordgraph = FALSE;
#endif
  tatom->next = bt->list;
  bt->list = tatom;
}

/** 
 * <JA>
 * 妈1パス姜位稿, 呈羌された帽胳トレリス攫鼠をフレ〖ム界に浩芹弥する. 
 * 
 * @param bt [i/o] 帽胳トレリス菇陇挛
 * </JA>
 * <EN>
 * Re-locate the stored atom lists per frame (will be called after the
 * 1st pass).
 * 
 * @param bt [i/o] word trellis structure
 * </EN>
 *
 * @callergraph
 * @callgraph
 * 
 */
void
bt_relocate_rw(BACKTRELLIS *bt)
{
  TRELLIS_ATOM *tre;
  int t;
  int totalnum, n;
  TRELLIS_ATOM **tmp;

  if (bt->framelen == 0) {
    bt->num = NULL;
    return;
  }

  bt->num = (int *)mybmalloc2(sizeof(int) * bt->framelen, &(bt->root));

  /* count number of trellis atom (= survived word end) for each frame */
  for (t=0;t<bt->framelen;t++) bt->num[t] = 0;
  totalnum = 0;
  for (tre=bt->list;tre;tre=tre->next) {
    /* the last frame (when triggered from sp to non-sp) should be discarded */
    if (tre->endtime >= bt->framelen) continue;
    bt->num[tre->endtime]++;
    totalnum++;
  }
  /* if no atom found, return here with all bt->num[t] set to 0 */
  if (totalnum <= 0) {
    bt->num = NULL;
    return;
  }
  
  /* allocate area */
  bt->rw  = (TRELLIS_ATOM ***)mybmalloc2(sizeof(TRELLIS_ATOM **) * bt->framelen, &(bt->root));
  tmp = (TRELLIS_ATOM **)mybmalloc2(sizeof(TRELLIS_ATOM *) * totalnum, &(bt->root));
  n = 0;
  for (t=0;t<bt->framelen;t++) {
    if (bt->num[t] > 0) {
      bt->rw[t] = (TRELLIS_ATOM **)&(tmp[n]);
      n += bt->num[t];
    }
  }
  /* then store the atoms */
  for (t=0;t<bt->framelen;t++) bt->num[t] = 0;
  for (tre=bt->list;tre;tre=tre->next) {
    /* the last frame (when triggered from sp to non-sp) should be discarded */
    if (tre->endtime >= bt->framelen) continue;
    t = tre->endtime;
    
    bt->rw[t][bt->num[t]] = tre;
    bt->num[t]++;
  }
}


/* 笆布の簇眶は bt_relocate_rw 悸乖稿にのみ蝗脱材墙となる. */
/* functions below this line should be called after bt_relocate_rw() */

/** 
 * <JA>
 * 绵肌デコ〖ディング箕, 妈１パス姜位稿に·
 * 掐蜗セグメントの尉眉に荒った呵锑帽胳簿棱を艰り叫し, それらを
 * 妈2パスにおける介袋/呵姜簿棱としてセットする. 
 * 
 * @param r [in] 千急借妄インスタンス
 * </JA>
 * <EN>
 * When using progressive decoding with short pause segmentation,
 * This function extracts the best word hypothesis on head and tail of
 * the current input segment just after the 1st pass ends,
 * and store them as start/end word in the following 2nd pass.
 * 
 * @param r [in] recognition process instance
 * </EN>
 *
 * @callergraph
 * @callgraph
 * 
 */
void
set_terminal_words(RecogProcess *r)