Word graph search. More...

#include <assert.h>
#include <string.h>
#include <math.h>
#include <sphinxbase/ckd_alloc.h>
#include <sphinxbase/listelem_alloc.h>
#include <sphinxbase/strfuncs.h>
#include <sphinxbase/err.h>
#include <sphinxbase/pio.h>
#include "pocketsphinx_internal.h"
#include "ps_lattice_internal.h"
#include "ngram_search.h"
#include "dict.h"

Macros
#define	MAX_PATHS 500 /* Max allowed active paths at any time */

#define	MAX_HYP_TRIES 10000

Functions
void	ps_lattice_link (ps_lattice_t dag, ps_latnode_t from, ps_latnode_t *to, int32 score, int32 ef)
	Create a directed link between "from" and "to" nodes, but if a link already exists, choose one with the best link_scr.

void	ps_lattice_penalize_fillers (ps_lattice_t *dag, int32 silpen, int32 fillpen)
	Insert penalty for fillers.

void	ps_lattice_delete_unreachable (ps_lattice_t *dag)
	Remove nodes marked as unreachable.

int32	ps_lattice_write (ps_lattice_t dag, char const filename)
	Write a lattice to disk.

int32	ps_lattice_write_htk (ps_lattice_t dag, char const filename)
	Write a lattice to disk in HTK format.

ps_lattice_t *	ps_lattice_read (ps_decoder_t ps, char const file)
	Read a lattice from a file on disk.

int	ps_lattice_n_frames (ps_lattice_t *dag)
	Get the number of frames in the lattice.

ps_lattice_t *	ps_lattice_init_search (ps_search_t *search, int n_frame)
	Construct an empty word graph with reference to a search structure.

ps_lattice_t *	ps_lattice_retain (ps_lattice_t *dag)
	Retain a lattice.

int	ps_lattice_free (ps_lattice_t *dag)
	Free a lattice.

logmath_t *	ps_lattice_get_logmath (ps_lattice_t *dag)
	Get the log-math computation object for this lattice.

ps_latnode_iter_t *	ps_latnode_iter (ps_lattice_t *dag)
	Start iterating over nodes in the lattice.

ps_latnode_iter_t *	ps_latnode_iter_next (ps_latnode_iter_t *itor)
	Move to next node in iteration.

void	ps_latnode_iter_free (ps_latnode_iter_t *itor)
	Stop iterating over nodes.

ps_latnode_t *	ps_latnode_iter_node (ps_latnode_iter_t *itor)
	Get node from iterator.

int	ps_latnode_times (ps_latnode_t node, int16 out_fef, int16 *out_lef)
	Get start and end time range for a node.

char const *	ps_latnode_word (ps_lattice_t dag, ps_latnode_t node)
	Get word string for this node.

char const *	ps_latnode_baseword (ps_lattice_t dag, ps_latnode_t node)
	Get base word string for this node.

int32	ps_latnode_prob (ps_lattice_t dag, ps_latnode_t node, ps_latlink_t **out_link)
	Get best posterior probability and associated acoustic score from a lattice node.

ps_latlink_iter_t *	ps_latnode_exits (ps_latnode_t *node)
	Iterate over exits from this node.

ps_latlink_iter_t *	ps_latnode_entries (ps_latnode_t *node)
	Iterate over entries to this node.

ps_latlink_iter_t *	ps_latlink_iter_next (ps_latlink_iter_t *itor)
	Get next link from a lattice link iterator.

void	ps_latlink_iter_free (ps_latlink_iter_t *itor)
	Stop iterating over links.

ps_latlink_t *	ps_latlink_iter_link (ps_latlink_iter_t *itor)
	Get link from iterator.

int	ps_latlink_times (ps_latlink_t link, int16 out_sf)
	Get start and end times from a lattice link.

ps_latnode_t *	ps_latlink_nodes (ps_latlink_t link, ps_latnode_t *out_src)
	Get destination and source nodes from a lattice link.

char const *	ps_latlink_word (ps_lattice_t dag, ps_latlink_t link)
	Get word string from a lattice link.

char const *	ps_latlink_baseword (ps_lattice_t dag, ps_latlink_t link)
	Get base word string from a lattice link.

ps_latlink_t *	ps_latlink_pred (ps_latlink_t *link)
	Get predecessor link in best path.

int32	ps_latlink_prob (ps_lattice_t dag, ps_latlink_t link, int32 *out_ascr)
	Get acoustic score and posterior probability from a lattice link.

char const *	ps_lattice_hyp (ps_lattice_t dag, ps_latlink_t link)
	Get hypothesis string after bestpath search.

ps_seg_t *	ps_lattice_seg_iter (ps_lattice_t dag, ps_latlink_t link, float32 lwf)
	Get hypothesis segmentation iterator after bestpath search.

latlink_list_t *	latlink_list_new (ps_lattice_t dag, ps_latlink_t link, latlink_list_t *next)
	Create a new lattice link element.

void	ps_lattice_pushq (ps_lattice_t dag, ps_latlink_t link)
	Add an edge to the traversal queue.

ps_latlink_t *	ps_lattice_popq (ps_lattice_t *dag)
	Remove an edge from the traversal queue.

void	ps_lattice_delq (ps_lattice_t *dag)
	Clear and reset the traversal queue.

ps_latlink_t *	ps_lattice_traverse_edges (ps_lattice_t dag, ps_latnode_t start, ps_latnode_t *end)
	Start a forward traversal of edges in a word graph.

ps_latlink_t *	ps_lattice_traverse_next (ps_lattice_t dag, ps_latnode_t end)
	Get the next link in forward traversal.

ps_latlink_t *	ps_lattice_reverse_edges (ps_lattice_t dag, ps_latnode_t start, ps_latnode_t *end)
	Start a reverse traversal of edges in a word graph.

ps_latlink_t *	ps_lattice_reverse_next (ps_lattice_t dag, ps_latnode_t start)
	Get the next link in reverse traversal.

ps_latlink_t *	ps_lattice_bestpath (ps_lattice_t dag, ngram_model_t lmset, float32 lwf, float32 ascale)
	Do N-Gram based best-path search on a word graph.

int32	ps_lattice_posterior (ps_lattice_t dag, ngram_model_t lmset, float32 ascale)
	Calculate link posterior probabilities on a word graph.

int32	ps_lattice_posterior_prune (ps_lattice_t *dag, int32 beam)
	Prune all links (and associated nodes) below a certain posterior probability.

ps_astar_t *	ps_astar_start (ps_lattice_t dag, ngram_model_t lmset, float32 lwf, int sf, int ef, int w1, int w2)
	Begin N-Gram based A* search on a word graph.

ps_latpath_t *	ps_astar_next (ps_astar_t *nbest)
	Find next best hypothesis of A* on a word graph.

char const *	ps_astar_hyp (ps_astar_t nbest, ps_latpath_t path)
	Get hypothesis string from A* search.

ps_seg_t *	ps_astar_seg_iter (ps_astar_t astar, ps_latpath_t path, float32 lwf)
	Get hypothesis segmentation from A* search.

void	ps_astar_finish (ps_astar_t *nbest)
	Finish N-best search, releasing resources associated with it.

Detailed Description

Word graph search.

Definition in file ps_lattice.c.

Macro Definition Documentation

◆ MAX_HYP_TRIES

#define MAX_HYP_TRIES 10000

Definition at line 1570 of file ps_lattice.c.

◆ MAX_PATHS

#define MAX_PATHS 500 /* Max allowed active paths at any time */

Definition at line 1569 of file ps_lattice.c.

Function Documentation

◆ latlink_list_new()

latlink_list_t * latlink_list_new	(	ps_lattice_t *	dag,
		ps_latlink_t *	link,
		latlink_list_t *	next
	)

Create a new lattice link element.

Definition at line 1042 of file ps_lattice.c.

References ps_lattice_s::latlink_list_alloc.

Referenced by ps_lattice_pushq().

◆ ps_astar_finish()

void ps_astar_finish ( ps_astar_t * nbest )

Finish N-best search, releasing resources associated with it.

Definition at line 1925 of file ps_lattice.c.

References ps_astar_s::hyps, and ps_astar_s::latpath_alloc.

Referenced by ps_nbest_free().

◆ ps_astar_hyp()

char const * ps_astar_hyp	(	ps_astar_t *	nbest,
		ps_latpath_t *	path
	)

Get hypothesis string from A* search.

Definition at line 1804 of file ps_lattice.c.

References ps_latnode_s::basewid, ps_astar_s::hyps, ps_latpath_s::node, ps_latpath_s::parent, and ps_lattice_s::search.

Referenced by ps_nbest_hyp().

◆ ps_astar_next()

ps_latpath_t * ps_astar_next ( ps_astar_t * nbest )

Find next best hypothesis of A* on a word graph.

Returns: a complete path, or NULL if no more hypotheses exist.

Definition at line 1771 of file ps_lattice.c.

References ps_lattice_s::end, ps_latnode_s::fef, ps_latpath_s::next, ps_latpath_s::node, and ps_latnode_s::sf.

Referenced by ps_nbest_next().

◆ ps_astar_seg_iter()

ps_seg_t * ps_astar_seg_iter	(	ps_astar_t *	astar,
		ps_latpath_t *	path,
		float32	lwf
	)

Get hypothesis segmentation from A* search.

Definition at line 1898 of file ps_lattice.c.

References ps_seg_s::lwf, ps_latpath_s::node, ps_latpath_s::parent, ps_seg_s::search, ps_lattice_s::search, and ps_seg_s::vt.

Referenced by ps_nbest_seg().

◆ ps_astar_start()

ps_astar_t * ps_astar_start	(	ps_lattice_t *	dag,
		ngram_model_t *	lmset,
		float32	lwf,
		int	sf,
		int	ef,
		int	w1,
		int	w2
	)

Begin N-Gram based A* search on a word graph.

Parameters

sf	Starting frame for N-best search.
ef	Ending frame for N-best search, or -1 for last frame.
w1	First context word, or -1 for none.
w2	Second context word, or -1 for none.

Returns: 0 for success, <0 on error.

Definition at line 1712 of file ps_lattice.c.

References ps_latnode_s::basewid, ps_lattice_s::end, ps_latnode_s::exits, ps_astar_s::latpath_alloc, ps_lattice_s::n_frames, ps_latnode_s::next, ps_latpath_s::node, ps_lattice_s::nodes, ps_latpath_s::parent, ps_latnode_s::rem_score, ps_latpath_s::score, SENSCR_SHIFT, ps_latnode_s::sf, and WORST_SCORE.

Referenced by ps_nbest().

◆ ps_latlink_baseword()

char const * ps_latlink_baseword	(	ps_lattice_t *	dag,
		ps_latlink_t *	link
	)

Get base word string from a lattice link.

Parameters

dag	Lattice to which node belongs.
link	Link inquired about

Returns: Base word string for this link

Definition at line 808 of file ps_lattice.c.

References ps_latnode_s::basewid, ps_lattice_s::dict, and ps_latlink_s::from.

◆ ps_latlink_iter_free()

void ps_latlink_iter_free ( ps_latlink_iter_t * itor )

Stop iterating over links.

Parameters

itor	Link iterator.

Definition at line 767 of file ps_lattice.c.

◆ ps_latlink_iter_link()

ps_latlink_t * ps_latlink_iter_link ( ps_latlink_iter_t * itor )

Get link from iterator.

Definition at line 773 of file ps_lattice.c.

◆ ps_latlink_iter_next()

ps_latlink_iter_t * ps_latlink_iter_next ( ps_latlink_iter_t * itor )

Get next link from a lattice link iterator.

Parameters

itor Iterator.

Returns: Updated iterator, or NULL if finished.

Definition at line 761 of file ps_lattice.c.

◆ ps_latlink_nodes()

ps_latnode_t * ps_latlink_nodes	(	ps_latlink_t *	link,
		ps_latnode_t **	out_src
	)

Get destination and source nodes from a lattice link.

Parameters

link	Link inquired about
out_src	Output: (optional) source node.

Returns: destination node

Definition at line 793 of file ps_lattice.c.

References ps_latlink_s::from, and ps_latlink_s::to.

◆ ps_latlink_pred()

ps_latlink_t * ps_latlink_pred ( ps_latlink_t * link )

Get predecessor link in best path.

Parameters

link	Link inquired about

Returns: Best previous link from bestpath search, if any. Otherwise NULL

Definition at line 816 of file ps_lattice.c.

◆ ps_latlink_prob()

int32 ps_latlink_prob	(	ps_lattice_t *	dag,
		ps_latlink_t *	link,
		int32 *	out_ascr
	)

Get acoustic score and posterior probability from a lattice link.

Parameters

dag	Lattice to which node belongs.
link	Link inquired about
out_ascr	Output: (optional) acoustic score.

Returns: Posterior probability for this link. Log is expressed in the log-base used in the decoder. To convert to linear floating-point, use logmath_exp(ps_lattice_get_logmath(), pprob).

Definition at line 822 of file ps_lattice.c.

References ps_latlink_s::alpha, ps_latlink_s::ascr, ps_latlink_s::beta, ps_lattice_s::norm, and SENSCR_SHIFT.

◆ ps_latlink_times()

int ps_latlink_times	(	ps_latlink_t *	link,
		int16 *	out_sf
	)

Get start and end times from a lattice link.

Note: these are inclusive - i.e. the last frame of this word is ef, not ef-1.

Parameters

link	Link inquired about.
out_sf	Output: (optional) start frame of this link.

Returns: End frame of this link.

Definition at line 779 of file ps_lattice.c.

References ps_latlink_s::ef, ps_latlink_s::from, and ps_latnode_s::sf.

◆ ps_latlink_word()

char const * ps_latlink_word	(	ps_lattice_t *	dag,
		ps_latlink_t *	link
	)

Get word string from a lattice link.

Parameters

dag	Lattice to which node belongs.
link	Link inquired about

Returns: Word string for this link (possibly a pronunciation variant).

Definition at line 800 of file ps_lattice.c.

References ps_lattice_s::dict, ps_latlink_s::from, and ps_latnode_s::wid.

◆ ps_latnode_baseword()

char const * ps_latnode_baseword	(	ps_lattice_t *	dag,
		ps_latnode_t *	node
	)

Get base word string for this node.

Parameters

dag	Lattice to which node belongs.
node	Node inquired about.

Returns: Base word string for this node.

Definition at line 726 of file ps_lattice.c.

References ps_latnode_s::basewid, and ps_lattice_s::dict.

◆ ps_latnode_entries()

ps_latlink_iter_t * ps_latnode_entries ( ps_latnode_t * node )

Iterate over entries to this node.

Parameters

node	Node inquired about.

Returns: Iterator over entry links to this node.

Definition at line 755 of file ps_lattice.c.

References ps_latnode_s::entries.

◆ ps_latnode_exits()

ps_latlink_iter_t * ps_latnode_exits ( ps_latnode_t * node )

Iterate over exits from this node.

Parameters

node	Node inquired about.

Returns: Iterator over exit links from this node.

Definition at line 749 of file ps_lattice.c.

References ps_latnode_s::exits.

◆ ps_latnode_iter()

ps_latnode_iter_t * ps_latnode_iter ( ps_lattice_t * dag )

Start iterating over nodes in the lattice.

Note: No particular order of traversal is guaranteed, and you should not depend on this.

Parameters

dag	Lattice to iterate over.

Returns: Iterator over lattice nodes.

Definition at line 688 of file ps_lattice.c.

References ps_lattice_s::nodes.

◆ ps_latnode_iter_free()

void ps_latnode_iter_free ( ps_latnode_iter_t * itor )

Stop iterating over nodes.

Parameters

itor	Node iterator.

Definition at line 700 of file ps_lattice.c.

◆ ps_latnode_iter_next()

ps_latnode_iter_t * ps_latnode_iter_next ( ps_latnode_iter_t * itor )

Move to next node in iteration.

Parameters

itor	Node iterator.

Returns: Updated node iterator, or NULL if finished

Definition at line 694 of file ps_lattice.c.

References ps_latnode_s::next.

◆ ps_latnode_iter_node()

ps_latnode_t * ps_latnode_iter_node ( ps_latnode_iter_t * itor )

Get node from iterator.

Definition at line 706 of file ps_lattice.c.

◆ ps_latnode_prob()

int32 ps_latnode_prob	(	ps_lattice_t *	dag,
		ps_latnode_t *	node,
		ps_latlink_t **	out_link
	)

Get best posterior probability and associated acoustic score from a lattice node.

Parameters

dag	Lattice to which node belongs.
node	Node inquired about.
out_link	Output: exit link with highest posterior probability

Returns: Posterior probability of the best link exiting this node. Log is expressed in the log-base used in the decoder. To convert to linear floating-point, use logmath_exp(ps_lattice_get_logmath(), pprob).

Definition at line 732 of file ps_lattice.c.

References ps_latlink_s::alpha, ps_latlink_s::beta, ps_latnode_s::exits, ps_lattice_s::lmath, and ps_lattice_s::norm.

◆ ps_latnode_times()

int ps_latnode_times	(	ps_latnode_t *	node,
		int16 *	out_fef,
		int16 *	out_lef
	)

Get start and end time range for a node.

Parameters

node	Node inquired about.
out_fef	Output: End frame of first exit from this node.
out_lef	Output: End frame of last exit from this node.

Returns: Start frame for all edges exiting this node.

Definition at line 712 of file ps_lattice.c.

References ps_latnode_s::fef, ps_latnode_s::lef, and ps_latnode_s::sf.

◆ ps_latnode_word()

char const * ps_latnode_word	(	ps_lattice_t *	dag,
		ps_latnode_t *	node
	)

Get word string for this node.

Parameters

dag	Lattice to which node belongs.
node	Node inquired about.

Returns: Word string for this node (possibly a pronunciation variant).

Definition at line 720 of file ps_lattice.c.

References ps_lattice_s::dict, and ps_latnode_s::wid.

◆ ps_lattice_bestpath()

ps_latlink_t * ps_lattice_bestpath	(	ps_lattice_t *	dag,
		ngram_model_t *	lmset,
		float32	lwf,
		float32	ascale
	)

Do N-Gram based best-path search on a word graph.

This function calculates both the best path as well as the forward probability used in confidence estimation.

Returns: Final link in best path, NULL on error.

Definition at line 1215 of file ps_lattice.c.

References ps_latlink_s::alpha, ps_latlink_s::ascr, ps_latnode_s::basewid, BETTER_THAN, ps_search_s::dict, ps_lattice_s::end, ps_latnode_s::entries, ps_latnode_s::exits, ps_lattice_s::final_node_ascr, ps_latlink_s::from, ps_latnode_s::lef, ps_lattice_s::lmath, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_s::norm, ps_latlink_s::path_scr, ps_lattice_traverse_edges(), ps_lattice_traverse_next(), ps_lattice_s::search, SENSCR_SHIFT, ps_latnode_s::sf, ps_lattice_s::start, ps_latlink_s::to, and ps_latnode_s::wid.

◆ ps_lattice_delete_unreachable()

void ps_lattice_delete_unreachable ( ps_lattice_t * dag )

Remove nodes marked as unreachable.

Definition at line 174 of file ps_lattice.c.

References ps_latnode_s::id, ps_latnode_s::next, ps_lattice_s::nodes, and ps_latnode_s::reachable.

Referenced by ngram_search_lattice(), ps_lattice_posterior_prune(), and ps_lattice_read().

◆ ps_lattice_delq()

void ps_lattice_delq ( ps_lattice_t * dag )

Clear and reset the traversal queue.

Definition at line 1083 of file ps_lattice.c.

References ps_lattice_popq().

Referenced by ps_lattice_reverse_edges(), ps_lattice_reverse_next(), ps_lattice_traverse_edges(), and ps_lattice_traverse_next().

◆ ps_lattice_free()

int ps_lattice_free ( ps_lattice_t * dag )

Free a lattice.

Returns: new reference count (0 if dag was freed)

Definition at line 665 of file ps_lattice.c.

References ps_lattice_s::dict, ps_lattice_s::hyp_str, ps_lattice_s::latlink_alloc, ps_lattice_s::latlink_list_alloc, ps_lattice_s::latnode_alloc, ps_lattice_s::lmath, and ps_lattice_s::refcount.

Referenced by ngram_search_lattice(), ps_search_base_free(), and ps_start_utt().

◆ ps_lattice_get_logmath()

logmath_t * ps_lattice_get_logmath ( ps_lattice_t * dag )

Get the log-math computation object for this lattice.

Returns: The log-math object for this lattice. The lattice retains ownership of this pointer, so you should not attempt to free it manually. Use logmath_retain() if you wish to reuse it elsewhere.

Definition at line 682 of file ps_lattice.c.

References ps_lattice_s::lmath.

◆ ps_lattice_hyp()

char const * ps_lattice_hyp	(	ps_lattice_t *	dag,
		ps_latlink_t *	link
	)

Get hypothesis string after bestpath search.

Definition at line 830 of file ps_lattice.c.

References ps_latnode_s::basewid, ps_lattice_s::dict, ps_latlink_s::from, ps_lattice_s::hyp_str, and ps_latlink_s::to.

◆ ps_lattice_init_search()

ps_lattice_t * ps_lattice_init_search	(	ps_search_t *	search,
		int	n_frame
	)

Construct an empty word graph with reference to a search structure.

Definition at line 639 of file ps_lattice.c.

References ps_search_s::acmod, ps_search_s::config, ps_search_s::dict, ps_lattice_s::dict, ps_lattice_s::frate, ps_lattice_s::latlink_alloc, ps_lattice_s::latlink_list_alloc, ps_lattice_s::latnode_alloc, acmod_s::lmath, ps_lattice_s::lmath, ps_lattice_s::n_frames, ps_lattice_s::refcount, ps_lattice_s::search, and ps_lattice_s::silence.

Referenced by ngram_search_lattice().

◆ ps_lattice_link()

void ps_lattice_link	(	ps_lattice_t *	dag,
		ps_latnode_t *	from,
		ps_latnode_t *	to,
		int32	score,
		int32	ef
	)

Create a directed link between "from" and "to" nodes, but if a link already exists, choose one with the best link_scr.

Definition at line 65 of file ps_lattice.c.

References ps_latlink_s::ascr, BETTER_THAN, ps_latlink_s::ef, ps_latnode_s::entries, ps_latnode_s::exits, ps_latlink_s::from, ps_lattice_s::latlink_alloc, ps_lattice_s::latlink_list_alloc, and ps_latlink_s::to.

Referenced by ngram_search_lattice(), and ps_lattice_read().

◆ ps_lattice_n_frames()

int ps_lattice_n_frames ( ps_lattice_t * dag )

Get the number of frames in the lattice.

Parameters

dag	The lattice in question.

Returns: Number of frames in this lattice.

Definition at line 633 of file ps_lattice.c.

References ps_lattice_s::n_frames.

◆ ps_lattice_penalize_fillers()

void ps_lattice_penalize_fillers	(	ps_lattice_t *	dag,
		int32	silpen,
		int32	fillpen
	)

Insert penalty for fillers.

Definition at line 106 of file ps_lattice.c.

References ps_latlink_s::ascr, ps_latnode_s::basewid, ps_lattice_s::dict, ps_lattice_s::end, ps_latnode_s::entries, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_s::silence, and ps_lattice_s::start.

Referenced by ngram_search_lattice(), and ps_lattice_read().

◆ ps_lattice_popq()

ps_latlink_t * ps_lattice_popq ( ps_lattice_t * dag )

Remove an edge from the traversal queue.

Definition at line 1066 of file ps_lattice.c.

References ps_lattice_s::latlink_list_alloc, ps_lattice_s::q_head, and ps_lattice_s::q_tail.

Referenced by ps_lattice_delq(), ps_lattice_reverse_next(), and ps_lattice_traverse_next().

◆ ps_lattice_posterior()

int32 ps_lattice_posterior	(	ps_lattice_t *	dag,
		ngram_model_t *	lmset,
		float32	ascale
	)

Calculate link posterior probabilities on a word graph.

This function assumes that bestpath search has already been done.

Returns: Posterior probability of the utterance as a whole.

Definition at line 1446 of file ps_lattice.c.

References ps_latlink_s::ascr, ps_latnode_s::basewid, ps_latlink_s::beta, BETTER_THAN, ps_lattice_s::dict, ps_lattice_s::end, ps_latnode_s::exits, ps_lattice_s::final_node_ascr, ps_latlink_s::from, ps_lattice_s::lmath, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_s::norm, ps_latlink_s::path_scr, ps_lattice_reverse_edges(), ps_lattice_reverse_next(), SENSCR_SHIFT, ps_lattice_s::start, and ps_latlink_s::to.

◆ ps_lattice_posterior_prune()

int32 ps_lattice_posterior_prune	(	ps_lattice_t *	dag,
		int32	beam
	)

Prune all links (and associated nodes) below a certain posterior probability.

This function assumes that ps_lattice_posterior() has already been called.

Parameters

beam	Minimum posterior probability for links. This is expressed in the log-base used in the decoder. To convert from linear floating-point, use logmath_log(ps_lattice_get_logmath(), prob).

Returns: number of arcs removed.

Definition at line 1524 of file ps_lattice.c.

References ps_latlink_s::alpha, ps_latlink_s::beta, ps_lattice_s::end, ps_latnode_s::entries, ps_latnode_s::exits, ps_latlink_s::from, ps_lattice_s::latlink_alloc, ps_lattice_s::latlink_list_alloc, ps_lattice_s::norm, ps_lattice_delete_unreachable(), ps_lattice_traverse_edges(), ps_lattice_traverse_next(), ps_latnode_s::reachable, ps_lattice_s::start, and ps_latlink_s::to.

◆ ps_lattice_pushq()

void ps_lattice_pushq	(	ps_lattice_t *	dag,
		ps_latlink_t *	link
	)

Add an edge to the traversal queue.

Definition at line 1054 of file ps_lattice.c.

References latlink_list_new(), ps_lattice_s::q_head, and ps_lattice_s::q_tail.

Referenced by ps_lattice_reverse_edges(), ps_lattice_reverse_next(), ps_lattice_traverse_edges(), and ps_lattice_traverse_next().

◆ ps_lattice_read()

ps_lattice_t * ps_lattice_read	(	struct ps_decoder_s *	ps,
		char const *	file
	)

Read a lattice from a file on disk.

Parameters

ps	Decoder to use for processing this lattice, or NULL.
file	Path to lattice file.

Returns: Newly created lattice, or NULL for failure.

Definition at line 387 of file ps_lattice.c.

References BAD_S3WID, ps_latnode_s::basewid, ps_search_s::config, ps_decoder_s::config, ps_decoder_s::dict, ps_lattice_s::dict, ps_lattice_s::end, ps_latnode_s::entries, ps_latnode_s::exits, ps_latnode_s::fef, ps_lattice_s::frate, ps_latnode_s::id, ps_lattice_s::latlink_alloc, ps_lattice_s::latlink_list_alloc, ps_lattice_s::latnode_alloc, ps_latnode_s::lef, ps_decoder_s::lmath, ps_lattice_s::lmath, ps_lattice_s::n_frames, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_delete_unreachable(), ps_lattice_link(), ps_lattice_penalize_fillers(), ps_latnode_s::reachable, ps_lattice_s::refcount, ps_decoder_s::search, ps_lattice_s::search, ps_latnode_s::sf, ps_lattice_s::silence, ps_lattice_s::start, ps_latnode_s::wid, WORSE_THAN, and WORST_SCORE.

◆ ps_lattice_retain()

ps_lattice_t * ps_lattice_retain ( ps_lattice_t * dag )

Retain a lattice.

This function retains ownership of a lattice for the caller, preventing it from being freed automatically. You must call ps_lattice_free() to free it after having called this function.

Returns: pointer to the retained lattice.

Definition at line 658 of file ps_lattice.c.

References ps_lattice_s::refcount.

◆ ps_lattice_reverse_edges()

ps_latlink_t * ps_lattice_reverse_edges	(	ps_lattice_t *	dag,
		ps_latnode_t *	start,
		ps_latnode_t *	end
	)

Start a reverse traversal of edges in a word graph.

Note: See ps_lattice_traverse_edges() for why this API is the way it is.

Parameters

dag	Lattice to be traversed.
start	Start node (goal) of traversal.
end	End node (source) of traversal.

Returns: First link in traversal.

Definition at line 1148 of file ps_lattice.c.

References ps_lattice_s::end, ps_latnode_s::entries, ps_latnode_s::exits, ps_latnode_s::fanin, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_delq(), ps_lattice_pushq(), and ps_lattice_reverse_next().

Referenced by ps_lattice_posterior().

◆ ps_lattice_reverse_next()

ps_latlink_t * ps_lattice_reverse_next	(	ps_lattice_t *	dag,
		ps_latnode_t *	start
	)

Get the next link in reverse traversal.

Parameters

dag	Lattice to be traversed.
start	Start node (goal) of traversal.

Returns: Next link in traversal.

Definition at line 1173 of file ps_lattice.c.

References ps_latnode_s::entries, ps_latnode_s::fanin, ps_latlink_s::from, ps_lattice_delq(), ps_lattice_popq(), ps_lattice_pushq(), and ps_lattice_s::start.

Referenced by ps_lattice_posterior(), and ps_lattice_reverse_edges().

◆ ps_lattice_seg_iter()

ps_seg_t * ps_lattice_seg_iter	(	ps_lattice_t *	dag,
		ps_latlink_t *	link,
		float32	lwf
	)

Get hypothesis segmentation iterator after bestpath search.

Definition at line 1006 of file ps_lattice.c.

References dag_seg_s::base, dag_seg_s::links, ps_seg_s::lwf, dag_seg_s::n_links, ps_lattice_s::norm, dag_seg_s::norm, ps_seg_s::search, ps_lattice_s::search, and ps_seg_s::vt.

◆ ps_lattice_traverse_edges()

ps_latlink_t * ps_lattice_traverse_edges	(	ps_lattice_t *	dag,
		ps_latnode_t *	start,
		ps_latnode_t *	end
	)

Start a forward traversal of edges in a word graph.

Note: A keen eye will notice an inconsistency in this API versus other types of iterators in PocketSphinx. The reason for this is that the traversal algorithm is much more efficient when it is able to modify the lattice structure. Therefore, to avoid giving the impression that multiple traversals are possible at once, no separate iterator structure is provided.

Parameters

dag	Lattice to be traversed.
start	Start node (source) of traversal.
end	End node (goal) of traversal.

Returns: First link in traversal.

Definition at line 1091 of file ps_lattice.c.

References ps_latnode_s::exits, ps_latnode_s::fanin, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_delq(), ps_lattice_pushq(), ps_lattice_traverse_next(), ps_lattice_s::start, and ps_latlink_s::to.

Referenced by ps_lattice_bestpath(), and ps_lattice_posterior_prune().

◆ ps_lattice_traverse_next()

ps_latlink_t * ps_lattice_traverse_next	(	ps_lattice_t *	dag,
		ps_latnode_t *	end
	)

Get the next link in forward traversal.

Parameters

dag	Lattice to be traversed.
end	End node (goal) of traversal.

Returns: Next link in traversal.

Definition at line 1117 of file ps_lattice.c.

References ps_lattice_s::end, ps_latnode_s::exits, ps_latnode_s::fanin, ps_lattice_delq(), ps_lattice_popq(), ps_lattice_pushq(), and ps_latlink_s::to.

Referenced by ps_lattice_bestpath(), ps_lattice_posterior_prune(), and ps_lattice_traverse_edges().

◆ ps_lattice_write()

int32 ps_lattice_write	(	ps_lattice_t *	dag,
		char const *	filename
	)

Write a lattice to disk.

Returns: 0 for success, <0 on failure.

Definition at line 210 of file ps_lattice.c.

References ps_latlink_s::ascr, BETTER_THAN, ps_lattice_s::dict, ps_lattice_s::end, ps_latnode_s::exits, ps_latnode_s::fef, ps_latnode_s::id, ps_latnode_s::lef, ps_lattice_s::lmath, ps_lattice_s::n_frames, ps_latnode_s::next, ps_latnode_s::node_id, ps_lattice_s::nodes, SENSCR_SHIFT, ps_latnode_s::sf, ps_lattice_s::start, ps_latlink_s::to, ps_latnode_s::wid, WORSE_THAN, and WORST_SCORE.

◆ ps_lattice_write_htk()

int32 ps_lattice_write_htk	(	ps_lattice_t *	dag,
		char const *	filename
	)

Write a lattice to disk in HTK format.

Returns: 0 for success, <0 on failure.

Definition at line 270 of file ps_lattice.c.

References ps_latlink_s::alpha, ps_latlink_s::ascr, ps_latlink_s::beta, BETTER_THAN, ps_lattice_s::dict, ps_lattice_s::end, ps_latnode_s::exits, ps_lattice_s::frate, ps_latnode_s::id, ps_lattice_s::lmath, ps_latnode_s::next, ps_lattice_s::nodes, ps_lattice_s::norm, ps_latnode_s::reachable, SENSCR_SHIFT, ps_latnode_s::sf, ps_lattice_s::start, ps_latlink_s::to, ps_latnode_s::wid, WORSE_THAN, and WORST_SCORE.

Macros

Functions

Detailed Description

Macro Definition Documentation

◆ MAX_HYP_TRIES

◆ MAX_PATHS

Function Documentation

◆ latlink_list_new()

◆ ps_astar_finish()

◆ ps_astar_hyp()

◆ ps_astar_next()

◆ ps_astar_seg_iter()

◆ ps_astar_start()

◆ ps_latlink_baseword()

◆ ps_latlink_iter_free()

◆ ps_latlink_iter_link()

◆ ps_latlink_iter_next()

◆ ps_latlink_nodes()

◆ ps_latlink_pred()

◆ ps_latlink_prob()

◆ ps_latlink_times()

◆ ps_latlink_word()

◆ ps_latnode_baseword()

◆ ps_latnode_entries()

◆ ps_latnode_exits()

◆ ps_latnode_iter()

◆ ps_latnode_iter_free()

◆ ps_latnode_iter_next()

◆ ps_latnode_iter_node()

◆ ps_latnode_prob()

◆ ps_latnode_times()

◆ ps_latnode_word()

◆ ps_lattice_bestpath()

◆ ps_lattice_delete_unreachable()

◆ ps_lattice_delq()

◆ ps_lattice_free()

◆ ps_lattice_get_logmath()

◆ ps_lattice_hyp()

◆ ps_lattice_init_search()

◆ ps_lattice_link()

◆ ps_lattice_n_frames()

◆ ps_lattice_penalize_fillers()

◆ ps_lattice_popq()

◆ ps_lattice_posterior()

◆ ps_lattice_posterior_prune()

◆ ps_lattice_pushq()

◆ ps_lattice_read()

◆ ps_lattice_retain()

◆ ps_lattice_reverse_edges()

◆ ps_lattice_reverse_next()

◆ ps_lattice_seg_iter()

◆ ps_lattice_traverse_edges()

◆ ps_lattice_traverse_next()

◆ ps_lattice_write()

◆ ps_lattice_write_htk()