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Diffstat (limited to 'media/pocketsphinx/src/ngram_search.h')
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1 files changed, 0 insertions, 433 deletions
diff --git a/media/pocketsphinx/src/ngram_search.h b/media/pocketsphinx/src/ngram_search.h deleted file mode 100644 index a9a2f4c25..000000000 --- a/media/pocketsphinx/src/ngram_search.h +++ /dev/null @@ -1,433 +0,0 @@ -/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */ -/* ==================================================================== - * Copyright (c) 2008 Carnegie Mellon University. All rights - * reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * - * This work was supported in part by funding from the Defense Advanced - * Research Projects Agency and the National Science Foundation of the - * United States of America, and the CMU Sphinx Speech Consortium. - * - * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND - * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, - * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR - * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL CARNEGIE MELLON UNIVERSITY - * NOR ITS EMPLOYEES BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT - * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, - * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY - * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - * - * ==================================================================== - * - */ - -/** - * @file ngram_search.h N-Gram based multi-pass search ("FBS") - */ - -#ifndef __NGRAM_SEARCH_H__ -#define __NGRAM_SEARCH_H__ - -/* SphinxBase headers. */ -#include <sphinxbase/cmd_ln.h> -#include <sphinxbase/logmath.h> -#include <sphinxbase/ngram_model.h> -#include <sphinxbase/listelem_alloc.h> -#include <sphinxbase/err.h> - -/* Local headers. */ -#include "pocketsphinx_internal.h" -#include "hmm.h" - -/** - * Lexical tree node data type. - * - * Not the first HMM for words, which multiplex HMMs based on - * different left contexts. This structure is used both in the - * dynamic HMM tree structure and in the per-word last-phone right - * context fanout. - */ -typedef struct chan_s { - hmm_t hmm; /**< Basic HMM structure. This *must* be first in - the structure because chan_t and root_chan_t are - sometimes used interchangeably */ - struct chan_s *next; /**< first descendant of this channel; or, in the - case of the last phone of a word, the next - alternative right context channel */ - struct chan_s *alt; /**< sibling; i.e., next descendant of parent HMM */ - - int32 ciphone; /**< ciphone for this node */ - union { - int32 penult_phn_wid; /**< list of words whose last phone follows this one; - this field indicates the first of the list; the - rest must be built up in a separate array. Used - only within HMM tree. -1 if none */ - int32 rc_id; /**< right-context id for last phone of words */ - } info; -} chan_t; - -/** - * Lexical tree node data type for the first phone (root) of each dynamic HMM tree - * structure. - * - * Each state may have a different parent static HMM. Most fields are - * similar to those in chan_t. - */ -typedef struct root_chan_s { - hmm_t hmm; /**< Basic HMM structure. This *must* be first in - the structure because chan_t and root_chan_t are - sometimes used interchangeably. */ - chan_t *next; /**< first descendant of this channel */ - - int32 penult_phn_wid; - int32 this_phn_wid; /**< list of words consisting of this single phone; - actually the first of the list, like penult_phn_wid; - -1 if none */ - int16 ciphone; /**< first ciphone of this node; all words rooted at this - node begin with this ciphone */ - int16 ci2phone; /**< second ciphone of this node; one root HMM for each - unique right context */ -} root_chan_t; - -/** - * Back pointer table (forward pass lattice; actually a tree) - */ -typedef struct bptbl_s { - frame_idx_t frame; /**< start or end frame */ - uint8 valid; /**< For absolute pruning */ - uint8 refcnt; /**< Reference count (number of successors) */ - int32 wid; /**< Word index */ - int32 bp; /**< Back Pointer */ - int32 score; /**< Score (best among all right contexts) */ - int32 s_idx; /**< Start of BScoreStack for various right contexts*/ - int32 real_wid; /**< wid of this or latest predecessor real word */ - int32 prev_real_wid; /**< wid of second-last real word */ - int16 last_phone; /**< last phone of this word */ - int16 last2_phone; /**< next-to-last phone of this word */ -} bptbl_t; - -/** - * Segmentation "iterator" for backpointer table results. - */ -typedef struct bptbl_seg_s { - ps_seg_t base; /**< Base structure. */ - int32 *bpidx; /**< Sequence of backpointer IDs. */ - int16 n_bpidx; /**< Number of backpointer IDs. */ - int16 cur; /**< Current position in bpidx. */ -} bptbl_seg_t; - -/* - * Candidates words for entering their last phones. Cleared and rebuilt in each - * frame. - * NOTE: candidates can only be multi-phone, real dictionary words. - */ -typedef struct lastphn_cand_s { - int32 wid; - int32 score; - int32 bp; - int32 next; /* next candidate starting at the same frame */ -} lastphn_cand_t; - -/* - * Since the same instance of a word (i.e., <word,start-frame>) reaches its last - * phone several times, we can compute its best BP and LM transition score info - * just the first time and cache it for future occurrences. Structure for such - * a cache. - */ -typedef struct { - int32 sf; /* Start frame */ - int32 dscr; /* Delta-score upon entering last phone */ - int32 bp; /* Best BP */ -} last_ltrans_t; - -#define CAND_SF_ALLOCSIZE 32 -typedef struct { - int32 bp_ef; - int32 cand; -} cand_sf_t; - -/* - * Structure for reorganizing the BP table entries in the current frame according - * to distinct right context ci-phones. Each entry contains the best BP entry for - * a given right context. Each successor word will pick up the correct entry based - * on its first ci-phone. - */ -typedef struct bestbp_rc_s { - int32 score; - int32 path; /* BP table index corresponding to this entry */ - int32 lc; /* right most ci-phone of above BP entry word */ -} bestbp_rc_t; - -#define NO_BP -1 - -/** - * Various statistics for profiling. - */ -typedef struct ngram_search_stats_s { - int32 n_phone_eval; - int32 n_root_chan_eval; - int32 n_nonroot_chan_eval; - int32 n_last_chan_eval; - int32 n_word_lastchan_eval; - int32 n_lastphn_cand_utt; - int32 n_fwdflat_chan; - int32 n_fwdflat_words; - int32 n_fwdflat_word_transition; - int32 n_senone_active_utt; -} ngram_search_stats_t; - - -/** - * N-Gram search module structure. - */ -struct ngram_search_s { - ps_search_t base; - ngram_model_t *lmset; /**< Set of language models. */ - hmm_context_t *hmmctx; /**< HMM context. */ - - /* Flags to quickly indicate which passes are enabled. */ - uint8 fwdtree; - uint8 fwdflat; - uint8 bestpath; - - /* State of procesing. */ - uint8 done; - - /* Allocators */ - listelem_alloc_t *chan_alloc; /**< For chan_t */ - listelem_alloc_t *root_chan_alloc; /**< For root_chan_t */ - listelem_alloc_t *latnode_alloc; /**< For latnode_t */ - - /** - * Search structure of HMM instances. - * - * The word triphone sequences (HMM instances) are transformed - * into tree structures, one tree per unique left triphone in the - * entire dictionary (actually diphone, since its left context - * varies dyamically during the search process). The entire set - * of trees of channels is allocated once and for all during - * initialization (since dynamic management of active CHANs is - * time consuming), with one exception: the last phones of words, - * that need multiple right context modelling, are not maintained - * in this static structure since there are too many of them and - * few are active at any time. Instead they are maintained as - * linked lists of CHANs, one list per word, and each CHAN in this - * set is allocated only on demand and freed if inactive. - */ - root_chan_t *root_chan; /**< Roots of search tree. */ - int32 n_root_chan_alloc; /**< Number of root_chan allocated */ - int32 n_root_chan; /**< Number of valid root_chan */ - int32 n_nonroot_chan; /**< Number of valid non-root channels */ - int32 max_nonroot_chan; /**< Maximum possible number of non-root channels */ - root_chan_t *rhmm_1ph; /**< Root HMMs for single-phone words */ - - /** - * Channels associated with a given word (only used for right - * contexts, single-phone words in fwdtree search, and word HMMs - * in fwdflat search). WARNING: For single-phone words and - * fwdflat search, this actually contains pointers to root_chan_t, - * which are allocated using root_chan_alloc. This is a - * suboptimal state of affairs. - */ - chan_t **word_chan; - bitvec_t *word_active; /**< array of active flags for all words. */ - - /** - * Each node in the HMM tree structure may point to a set of words - * whose last phone would follow that node in the tree structure - * (but is not included in the tree structure for reasons - * explained above). The channel node points to one word in this - * set of words. The remaining words are linked through - * homophone_set[]. - * - * Single-phone words are not represented in the HMM tree; they - * are kept in word_chan. - * - * Specifically, homophone_set[w] = wid of next word in the same - * set as w. - */ - int32 *homophone_set; - int32 *single_phone_wid; /**< list of single-phone word ids */ - int32 n_1ph_words; /**< Number single phone words in dict (total) */ - int32 n_1ph_LMwords; /**< Number single phone dict words also in LM; - these come first in single_phone_wid */ - /** - * Array of active channels for current and next frame. - * - * In any frame, only some HMM tree nodes are active. - * active_chan_list[f mod 2] = list of nonroot channels in the HMM - * tree active in frame f. - */ - chan_t ***active_chan_list; - int32 n_active_chan[2]; /**< Number entries in active_chan_list */ - /** - * Array of active multi-phone words for current and next frame. - * - * Similarly to active_chan_list, active_word_list[f mod 2] = list - * of word ids for which active channels exist in word_chan in - * frame f. - * - * Statically allocated single-phone words are always active and - * should not appear in this list. - */ - int32 **active_word_list; - int32 n_active_word[2]; /**< Number entries in active_word_list */ - - /* - * FIXME: Document all of these bits. - */ - lastphn_cand_t *lastphn_cand; - int32 n_lastphn_cand; - last_ltrans_t *last_ltrans; /* one per word */ - int32 cand_sf_alloc; - cand_sf_t *cand_sf; - bestbp_rc_t *bestbp_rc; - - bptbl_t *bp_table; /* Forward pass lattice */ - int32 bpidx; /* First free BPTable entry */ - int32 bp_table_size; - int32 *bscore_stack; /* Score stack for all possible right contexts */ - int32 bss_head; /* First free BScoreStack entry */ - int32 bscore_stack_size; - - int32 n_frame_alloc; /**< Number of frames allocated in bp_table_idx and friends. */ - int32 n_frame; /**< Number of frames actually present. */ - int32 *bp_table_idx; /* First BPTable entry for each frame */ - int32 *word_lat_idx; /* BPTable index for any word in current frame; - cleared before each frame */ - - /* - * Flat lexicon (2nd pass) search stuff. - */ - ps_latnode_t **frm_wordlist; /**< List of active words in each frame. */ - int32 *fwdflat_wordlist; /**< List of active word IDs for utterance. */ - bitvec_t *expand_word_flag; - int32 *expand_word_list; - int32 n_expand_words; - int32 min_ef_width; - int32 max_sf_win; - float32 fwdflat_fwdtree_lw_ratio; - - int32 best_score; /**< Best Viterbi path score. */ - int32 last_phone_best_score; /**< Best Viterbi path score for last phone. */ - int32 renormalized; - - /* - * DAG (3rd pass) search stuff. - */ - float32 bestpath_fwdtree_lw_ratio; - float32 ascale; /**< Acoustic score scale for posterior probabilities. */ - - ngram_search_stats_t st; /**< Various statistics for profiling. */ - ptmr_t fwdtree_perf; - ptmr_t fwdflat_perf; - ptmr_t bestpath_perf; - int32 n_tot_frame; - - /* A collection of beam widths. */ - int32 beam; - int32 dynamic_beam; - int32 pbeam; - int32 wbeam; - int32 lpbeam; - int32 lponlybeam; - int32 fwdflatbeam; - int32 fwdflatwbeam; - int32 fillpen; - int32 silpen; - int32 wip; - int32 nwpen; - int32 pip; - int32 maxwpf; - int32 maxhmmpf; -}; -typedef struct ngram_search_s ngram_search_t; - -/** - * Initialize the N-Gram search module. - */ -ps_search_t *ngram_search_init(ngram_model_t *lm, - cmd_ln_t *config, - acmod_t *acmod, - dict_t *dict, - dict2pid_t *d2p); - -/** - * Finalize the N-Gram search module. - */ -void ngram_search_free(ps_search_t *ngs); - -/** - * Record the current frame's index in the backpointer table. - * - * @return the current backpointer index. - */ -int ngram_search_mark_bptable(ngram_search_t *ngs, int frame_idx); - -/** - * Enter a word in the backpointer table. - */ -void ngram_search_save_bp(ngram_search_t *ngs, int frame_idx, int32 w, - int32 score, int32 path, int32 rc); - -/** - * Allocate last phone channels for all possible right contexts for word w. - */ -void ngram_search_alloc_all_rc(ngram_search_t *ngs, int32 w); - -/** - * Allocate last phone channels for all possible right contexts for word w. - */ -void ngram_search_free_all_rc(ngram_search_t *ngs, int32 w); - -/** - * Find the best word exit for the current frame in the backpointer table. - * - * @return the backpointer index of the best word exit. - */ -int ngram_search_find_exit(ngram_search_t *ngs, int frame_idx, int32 *out_best_score, int32 *out_is_final); - -/** - * Backtrace from a given backpointer index to obtain a word hypothesis. - * - * @return a <strong>read-only</strong> string with the best hypothesis. - */ -char const *ngram_search_bp_hyp(ngram_search_t *ngs, int bpidx); - -/** - * Compute language and acoustic scores for backpointer table entries. - */ -void ngram_compute_seg_scores(ngram_search_t *ngs, float32 lwf); - -/** - * Construct a word lattice from the current hypothesis. - */ -ps_lattice_t *ngram_search_lattice(ps_search_t *search); - -/** - * Get the exit score for a backpointer entry with a given right context. - */ -int32 ngram_search_exit_score(ngram_search_t *ngs, bptbl_t *pbe, int rcphone); - -/** - * Sets the global language model. - * - * Sets the language model to use if nothing was passed in configuration - */ -void ngram_search_set_lm(ngram_model_t *lm); - -#endif /* __NGRAM_SEARCH_H__ */ |