/* -*- 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 #include /* 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