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Diffstat (limited to 'media/pocketsphinx/src/fsg_history.h')
| -rw-r--r-- | media/pocketsphinx/src/fsg_history.h | 215 |
1 files changed, 215 insertions, 0 deletions
diff --git a/media/pocketsphinx/src/fsg_history.h b/media/pocketsphinx/src/fsg_history.h new file mode 100644 index 000000000..5eaad65e2 --- /dev/null +++ b/media/pocketsphinx/src/fsg_history.h @@ -0,0 +1,215 @@ +/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */ +/* ==================================================================== + * Copyright (c) 1999-2004 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 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. + * + * ==================================================================== + * + */ +/* + * fsg_history.h -- FSG Viterbi decode history + * + * ********************************************** + * CMU ARPA Speech Project + * + * Copyright (c) 1999 Carnegie Mellon University. + * ALL RIGHTS RESERVED. + * ********************************************** + * + * HISTORY + * + * $Log: fsg_history.h,v $ + * Revision 1.1.1.1 2006/05/23 18:45:02 dhuggins + * re-importation + * + * Revision 1.1 2004/07/16 00:57:12 egouvea + * Added Ravi's implementation of FSG support. + * + * Revision 1.7 2004/07/07 22:30:35 rkm + * *** empty log message *** + * + * Revision 1.6 2004/07/07 13:56:33 rkm + * Added reporting of (acoustic score - best senone score)/frame + * + * Revision 1.5 2004/06/25 14:49:08 rkm + * Optimized size of history table and speed of word transitions by maintaining only best scoring word exits at each state + * + * Revision 1.4 2004/06/23 20:32:16 rkm + * *** empty log message *** + * + * Revision 1.3 2004/05/27 15:16:08 rkm + * *** empty log message *** + * + * + * 25-Feb-2004 M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University + * Started, based on S3.3 version. + */ + + +#ifndef __S2_FSG_HISTORY_H__ +#define __S2_FSG_HISTORY_H__ + + +/* SphinxBase headers. */ +#include <sphinxbase/prim_type.h> +#include <sphinxbase/fsg_model.h> + +/* Local headers. */ +#include "blkarray_list.h" +#include "fsg_lextree.h" +#include "dict.h" + +/* + * The Viterbi history structure. This is a tree, with the root at the + * FSG start state, at frame 0, with a null predecessor. + */ + +/* + * A single Viterbi history entry + */ +typedef struct fsg_hist_entry_s { + fsg_link_t *fsglink; /* Link taken result in this entry */ + int32 score; /* Total path score at the end of this + transition */ + int32 pred; /* Predecessor entry; -1 if none */ + frame_idx_t frame; /* Ending frame for this entry */ + int16 lc; /* Left context provided by this entry to + succeeding words */ + fsg_pnode_ctxt_t rc; /* Possible right contexts to which this entry + applies */ +} fsg_hist_entry_t; + +/* Access macros */ +#define fsg_hist_entry_fsglink(v) ((v)->fsglink) +#define fsg_hist_entry_frame(v) ((v)->frame) +#define fsg_hist_entry_score(v) ((v)->score) +#define fsg_hist_entry_pred(v) ((v)->pred) +#define fsg_hist_entry_lc(v) ((v)->lc) +#define fsg_hist_entry_rc(v) ((v)->rc) + + +/* + * The entire tree of history entries (fsg_history_t.entries). + * Optimization: In a given frame, there may be several history entries, with + * the same left and right phonetic context, terminating in a particular state. + * Only the best scoring one of these needs to be saved, since everything else + * will be pruned according to the Viterbi algorithm. frame_entries is used + * temporarily in each frame to determine these best scoring entries in that + * frame. Only the ones not pruned are transferred to entries at the end of + * the frame. However, null transitions are a problem since they create + * entries that depend on entries created in the CURRENT frame. Hence, this + * pruning is done in two stages: first for the non-null transitions, and then + * for the null transitions alone. (This solution is sub-optimal, and can be + * improved with a little more work. SMOP.) + * Why is frame_entries a list? Each entry has a unique terminating state, + * and has a unique lc CIphone. But it has a SET of rc CIphones. + * frame_entries[s][lc] is an ordered list of entries created in the current + * frame, terminating in state s, and with left context lc. The list is in + * descending order of path score. When a new entry with (s,lc) arrives, + * its position in the list is determined. Then its rc set is modified by + * subtracting the union of the rc's of all its predecessors (i.e., better + * scoring entries). If the resulting rc set is empty, the entry is discarded. + * Otherwise, it is inserted, and the rc sets of all downstream entries in the + * list are updated by subtracting the new entry's rc. If any of them becomes + * empty, it is also discarded. + * As mentioned earlier, this procedure is applied in two stages, for the + * non-null transitions, and the null transitions, separately. + */ +typedef struct fsg_history_s { + fsg_model_t *fsg; /* The FSG for which this object applies */ + blkarray_list_t *entries; /* A list of history table entries; the root + entry is the first element of the list */ + glist_t **frame_entries; + int n_ciphone; +} fsg_history_t; + + +/* + * One-time intialization: Allocate and return an initially empty history + * module. + */ +fsg_history_t *fsg_history_init(fsg_model_t *fsg, dict_t *dict); + +void fsg_history_utt_start(fsg_history_t *h); + +void fsg_history_utt_end(fsg_history_t *h); + + +/* + * Create a history entry recording the completion of the given FSG + * transition, at the end of the given frame, with the given score, and + * the given predecessor history entry. + * The entry is initially temporary, and may be superseded by another + * with a higher score. The surviving entries must be transferred to + * the main history table, via fsg_history_end_frame(). + */ +void fsg_history_entry_add (fsg_history_t *h, + fsg_link_t *l, /* FSG transition */ + int32 frame, + int32 score, + int32 pred, + int32 lc, + fsg_pnode_ctxt_t rc); + +/* + * Transfer the surviving history entries for this frame into the permanent + * history table. This function can be called several times during a frame. + * Each time, the entries surviving so far are transferred, and the temporary + * lists cleared. This feature is used to handle the entries due to non-null + * transitions and null transitions separately. + */ +void fsg_history_end_frame (fsg_history_t *h); + + +/* Clear the hitory table */ +void fsg_history_reset (fsg_history_t *h); + + +/* Return the number of valid entries in the given history table */ +int32 fsg_history_n_entries (fsg_history_t *h); + +/* + * Return a ptr to the history entry for the given ID; NULL if there is no + * such entry. + */ +fsg_hist_entry_t *fsg_history_entry_get(fsg_history_t *h, int32 id); + + +/* + * Switch the FSG associated with the given history module. Should be done + * when the history list is empty. If not empty, the list is cleared. + */ +void fsg_history_set_fsg (fsg_history_t *h, fsg_model_t *fsg, dict_t *dict); + +/* Free the given Viterbi search history object */ +void fsg_history_free (fsg_history_t *h); + +/* Print the entire history */ +void fsg_history_print(fsg_history_t *h, dict_t *dict); + +#endif |