dict2pid.h File Reference

Building triphones for a dictionary. More...

#include <stdio.h>
#include <logmath.h>
#include "s3types.h"
#include "mdef.h"
#include "dict.h"
#include "ctxt_table.h"

Go to the source code of this file.

Classes

struct  dict2pid_t
 Building composite triphone (as well as word internal triphones) with the dictionary. More...

Defines

#define dict2pid_internal(d, w, p)   ((d)->internal[w][p])
#define dict2pid_n_comstate(d)   ((d)->n_comstate)
#define dict2pid_n_comsseq(d)   ((d)->n_comsseq)
#define dict2pid_is_composite(d)   ((d)->is_composite)
#define IS_COMPOSITE   1
#define NOT_COMPOSITE   0

Functions

dict2pid_tdict2pid_build (mdef_t *mdef, dict_t *dict, int32 is_composite, logmath_t *logmath)
void dict2pid_free (dict2pid_t *d2p)
void dict2pid_comsenscr (dict2pid_t *d2p, int32 *senscr, int32 *comsenscr)
void dict2pid_comsseq2sen_active (dict2pid_t *d2p, mdef_t *mdef, uint8 *comssid, uint8 *sen)
void dict2pid_dump (FILE *fp, dict2pid_t *d2p, mdef_t *mdef, dict_t *dict)
void dict2pid_report (dict2pid_t *d2p)
int32 get_rc_nssid (dict2pid_t *d2p, s3wid_t w, dict_t *dict)
s3cipid_tdict2pid_get_rcmap (dict2pid_t *d2p, s3wid_t w, dict_t *dict)

Detailed Description

Building triphones for a dictionary.

This is one of the more complicated parts of a cross-word triphone model decoder. The first and last phones of each word get their left and right contexts, respectively, from other words. For single-phone words, both its contexts are from other words, simultaneously. As these words are not known beforehand, life gets complicated. In this implementation, when we do not wish to distinguish between distinct contexts, we use a COMPOSITE triphone (a bit like BBN's fast-match implementation), by clubbing together all possible contexts.

There are 3 cases:

1. Internal phones, and boundary phones without any specific context, in each word. The boundary phones are modelled using composite phones, internal ones using ordinary phones.

2. The first phone of a multi-phone word, for a specific history (i.e., in a 2g/3g/4g... tree) has known left and right contexts. The possible left contexts are limited to the possible last phones of the history. So it can be modelled separately, efficiently, as an ordinary triphone.

3. The one phone in a single-phone word, for a specific history (i.e., in a 2g/3g/4g... tree) has a known left context, but unknown right context. It is modelled using a composite triphone. (Note that right contexts are always composite, left contexts are composite only in the unigram tree.)

A composite triphone is formed as follows. (NOTE: this assumes that all CIphones/triphones have the same HMM topology, specifically, no. of states.) A composite triphone represents a situation where either the left or the right context (or both) for a given base phone is unknown. That is, it represents the set of all possible ordinary triphones derivable from * the unkown context(s). Let us call this set S. It is modelled using the same HMM topology * as the ordinary triphones, but with COMPOSITE states. A composite state (in a given position * in the HMM state topology) is the set of states (senones) at that position derived from S.

Actually, we generally deal with COMPOSITE SENONE-SEQUENCES rather than COMPOSITE PHONES. The former are compressed forms of the latter, by virtue of state sharing among phones. (See mdef.h.)

In 3.6, the composite triphone will only be build when -composite 1 (default) is specified. Other than that, full triphone expansion will be carried out in run-time


Define Documentation

#define dict2pid_internal ( d,
w,
 )     ((d)->internal[w][p])

Access macros; not designed for arbitrary use return internal dict2pid

#define dict2pid_is_composite (  )     ((d)->is_composite)

return whether dict2pid is in composite triphone mode or not

#define dict2pid_n_comsseq (  )     ((d)->n_comsseq)

return number of composite state sequence

#define dict2pid_n_comstate (  )     ((d)->n_comstate)

return number of composite state

#define IS_COMPOSITE   1
#define NOT_COMPOSITE   0

Function Documentation

dict2pid_t* dict2pid_build ( mdef_t mdef,
dict_t dict,
int32  is_composite,
logmath_t *  logmath 
)

Build the dict2pid structure for the given model/dictionary

This segments of code take care of the initialization of internal[0] and ldiph[b][r][l]

This part will take care of the initialization of internal[pronlen-1] and rdiph[b][l][r]. Notice that this is symmetric to the first part of the code.

Parameters:
mdef A model definition
dict An initialized dictionary
is_composite Whether composite triphones will be built

References BAD_S3SENID, BAD_S3SSID, dict2pid_t::comsseq, dict2pid_t::comstate, dict2pid_t::comwt, dict_pron, dict_pronlen, dict_size, dict_wordstr, dict2pid_t::internal, dict2pid_t::is_composite, IS_S3SENID, dict2pid_t::ldiph_lc, logs3(), dict2pid_t::lrdiph_rc, dict2pid_t::lrssid, mdef_n_ciphone, mdef_phone_id_nearest(), mdef_pid2ssid, dict2pid_t::n_ci, mdef_t::n_ciphone, dict2pid_t::n_comsseq, dict2pid_t::n_comstate, dict2pid_t::n_dictsize, mdef_t::n_emit_state, NOT_S3SSID, dict2pid_t::rdiph_rc, dict2pid_t::rssid, dict2pid_t::single_lc, WORD_POSN_BEGIN, WORD_POSN_INTERNAL, and WORD_POSN_SINGLE.

void dict2pid_comsenscr ( dict2pid_t d2p,
int32 *  senscr,
int32 *  comsenscr 
)

Compute composite senone scores from ordinary senone scores (max of component senones)

Populate composite senone score array.

The composite senone score is the maximum of its component senones' scores, scaled down by the number of component senones.

Parameters:
d2p In: a dict2pid_t structure
senscr In: Ordinary senone scores
comsenscr Out: Composite senone scores

References dict2pid_t::comstate, dict2pid_t::comwt, dict2pid_t::n_comstate, and NOT_S3SENID.

void dict2pid_comsseq2sen_active ( dict2pid_t d2p,
mdef_t mdef,
uint8 *  comssid,
uint8 *  sen 
)

Mark active senones as indicated by the input array of composite senone-sequence active flags. Caller responsible for allocating and clearing sen[] before calling this function.

Mark senones active based on a set of active composite senones.

Parameters:
d2p In: a dict2pid_t structure
mdef In: a mdef_t structure
comssid In: Active flag for each comssid
sen In/Out: Active flags set for senones indicated by the active comssid

References dict2pid_t::comsseq, dict2pid_t::comstate, IS_S3SENID, mdef_n_emit_state, and dict2pid_t::n_comsseq.

void dict2pid_dump ( FILE *  fp,
dict2pid_t d2p,
mdef_t mdef,
dict_t dict 
)
void dict2pid_free ( dict2pid_t d2p  ) 
s3cipid_t* dict2pid_get_rcmap ( dict2pid_t d2p,
s3wid_t  w,
dict_t dict 
)

Get RC map

Parameters:
d2p In: a dict2pid
w In: a wid
dict In: a dictionary

References xwdssid_t::cimap, dictword_t::ciphone, dict2pid_t::lrssid, dictword_t::pronlen, dict2pid_t::rssid, and dict_t::word.

void dict2pid_report ( dict2pid_t d2p  ) 

Report a dict2pid data structure

Parameters:
d2p In: a dict2pid_t structure

References dict2pid_t::is_composite, dict2pid_t::n_comsseq, and dict2pid_t::n_comstate.

int32 get_rc_nssid ( dict2pid_t d2p,
s3wid_t  w,
dict_t dict 
)

Get number of rc

ARCHAN, A duplicate of get_rc_npid in ctxt_table.h. I doubt whether it is correct because the compressed map has not been checked.

Parameters:
d2p In: a dict2pid
w In: a wid
dict In: a dictionary

References dictword_t::ciphone, dict2pid_t::lrssid, xwdssid_t::n_ssid, dictword_t::pronlen, dict2pid_t::rssid, and dict_t::word.


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