pocketsphinx / src /kws_search.h
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/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
* Copyright (c) 2013 Carnegie Mellon University. All rights
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* 1. Redistributions of source code must retain the above copyright
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* 2. Redistributions in binary form must reproduce the above copyright
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* THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
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* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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*/
/*
* kws_search.h -- Search structures for keyphrase spotting.
*/
#ifndef __KWS_SEARCH_H__
#define __KWS_SEARCH_H__
#include <pocketsphinx.h>
#include "util/glist.h"
#include "pocketsphinx_internal.h"
#include "kws_detections.h"
#include "hmm.h"
#ifdef __cplusplus
extern "C" {
#endif
#if 0
}
#endif
/**
* Segmentation "iterator" for KWS history.
*/
typedef struct kws_seg_s {
ps_seg_t base; /**< Base structure. */
kws_detection_t **detections; /**< Vector of current detections. */
frame_idx_t last_frame; /**< Last frame to raise the detection. */
int n_detections; /**< Size of vector. */
int pos; /**< Position of iterator. */
} kws_seg_t;
typedef struct kws_keyphrase_s {
char* word;
int32 threshold;
hmm_t* hmms;
int32 n_hmms;
} kws_keyphrase_t;
/**
* Implementation of KWS search structure.
*/
typedef struct kws_search_s {
ps_search_t base;
hmm_context_t *hmmctx; /**< HMM context. */
glist_t keyphrases; /**< Keyphrases to spot */
kws_detections_t *detections; /**< Keyword spotting history */
frame_idx_t frame; /**< Frame index */
int32 beam;
int32 plp; /**< Phone loop probability */
int32 bestscore; /**< For beam pruning */
int32 def_threshold; /**< default threshold for p(hyp)/p(altern) ratio */
int32 delay; /**< Delay to wait for best detection score */
int32 n_pl; /**< Number of CI phones */
hmm_t *pl_hmms; /**< Phone loop hmms - hmms of CI phones */
ptmr_t perf; /**< Performance counter */
int32 n_tot_frame;
} kws_search_t;
/**
* Create, initialize and return a search module. Gets keyphrases either
* from keyphrase or from a keyphrase file.
*/
ps_search_t *kws_search_init(const char *name,
const char *keyphrase,
const char *keyfile,
ps_config_t * config,
acmod_t * acmod,
dict_t * dict, dict2pid_t * d2p);
/**
* Deallocate search structure.
*/
void kws_search_free(ps_search_t * search);
/**
* Update KWS search module for new key phrase.
*/
int kws_search_reinit(ps_search_t * kwss, dict_t * dict, dict2pid_t * d2p);
/**
* Prepare the KWS search structure for beginning decoding of the next
* utterance.
*/
int kws_search_start(ps_search_t * search);
/**
* Step one frame forward through the Viterbi search.
*/
int kws_search_step(ps_search_t * search, int frame_idx);
/**
* Windup and clean the KWS search structure after utterance.
*/
int kws_search_finish(ps_search_t * search);
/**
* Get hypothesis string from the KWS search.
*/
char const *kws_search_hyp(ps_search_t * search, int32 * out_score);
/**
* Get active keyphrases
*/
char* kws_search_get_keyphrases(ps_search_t * search);
#ifdef __cplusplus
} /* extern "C" */
#endif
#endif /* __KWS_SEARCH_H__ */