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tenfourfox/media/pocketsphinx/src/ngram_search_fwdtree.c
Cameron Kaiser c9b2922b70 hello FPR
2017-04-19 00:56:45 -07:00

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/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
* Copyright (c) 2008 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 work was supported in part by funding from the Defense Advanced
* Research Projects Agency and the National Science Foundation of the
* United States of America, and the CMU Sphinx Speech Consortium.
*
* 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.
*
* ====================================================================
*
*/
/**
* @file ngram_search_fwdtree.c Lexicon tree search.
*/
/* System headers. */
#include <string.h>
#include <assert.h>
/* SphinxBase headers. */
#include <sphinxbase/ckd_alloc.h>
#include <sphinxbase/listelem_alloc.h>
#include <sphinxbase/err.h>
/* Local headers. */
#include "ngram_search_fwdtree.h"
#include "phone_loop_search.h"
/* Turn this on to dump channels for debugging */
#define __CHAN_DUMP__ 0
#if __CHAN_DUMP__
#define chan_v_eval(chan) hmm_dump_vit_eval(&(chan)->hmm, stderr)
#else
#define chan_v_eval(chan) hmm_vit_eval(&(chan)->hmm)
#endif
/*
* Allocate that part of the search channel tree structure that is independent of the
* LM in use.
*/
static void
init_search_tree(ngram_search_t *ngs)
{
int32 w, ndiph, i, n_words, n_ci;
dict_t *dict = ps_search_dict(ngs);
bitvec_t *dimap;
n_words = ps_search_n_words(ngs);
ngs->homophone_set = ckd_calloc(n_words, sizeof(*ngs->homophone_set));
/* Find #single phone words, and #unique first diphones (#root channels) in dict. */
ndiph = 0;
ngs->n_1ph_words = 0;
n_ci = bin_mdef_n_ciphone(ps_search_acmod(ngs)->mdef);
/* Allocate a bitvector with flags for each possible diphone. */
dimap = bitvec_alloc(n_ci * n_ci);
for (w = 0; w < n_words; w++) {
if (!dict_real_word(dict, w))
continue;
if (dict_is_single_phone(dict, w))
++ngs->n_1ph_words;
else {
int ph0, ph1;
ph0 = dict_first_phone(dict, w);
ph1 = dict_second_phone(dict, w);
/* Increment ndiph the first time we see a diphone. */
if (bitvec_is_clear(dimap, ph0 * n_ci + ph1)) {
bitvec_set(dimap, ph0 * n_ci + ph1);
++ndiph;
}
}
}
E_INFO("%d unique initial diphones\n", ndiph);
bitvec_free(dimap);
/* Add remaining dict words (</s>, <s>, <sil>, noise words) to single-phone words */
ngs->n_1ph_words += dict_num_fillers(dict) + 2;
ngs->n_root_chan_alloc = ndiph + 1;
/* Verify that these are all *actually* single-phone words,
* otherwise really bad things will happen to us. */
for (w = 0; w < n_words; ++w) {
if (dict_real_word(dict, w))
continue;
if (!dict_is_single_phone(dict, w)) {
E_WARN("Filler word %d = %s has more than one phone, ignoring it.\n",
w, dict_wordstr(dict, w));
--ngs->n_1ph_words;
}
}
/* Allocate and initialize root channels */
ngs->root_chan =
ckd_calloc(ngs->n_root_chan_alloc, sizeof(*ngs->root_chan));
for (i = 0; i < ngs->n_root_chan_alloc; i++) {
hmm_init(ngs->hmmctx, &ngs->root_chan[i].hmm, TRUE, -1, -1);
ngs->root_chan[i].penult_phn_wid = -1;
ngs->root_chan[i].next = NULL;
}
/* Permanently allocate and initialize channels for single-phone
* words (1/word). */
ngs->rhmm_1ph = ckd_calloc(ngs->n_1ph_words, sizeof(*ngs->rhmm_1ph));
i = 0;
for (w = 0; w < n_words; w++) {
if (!dict_is_single_phone(dict, w))
continue;
/* Use SIL as right context for these. */
ngs->rhmm_1ph[i].ci2phone = bin_mdef_silphone(ps_search_acmod(ngs)->mdef);
ngs->rhmm_1ph[i].ciphone = dict_first_phone(dict, w);
hmm_init(ngs->hmmctx, &ngs->rhmm_1ph[i].hmm, TRUE,
bin_mdef_pid2ssid(ps_search_acmod(ngs)->mdef, ngs->rhmm_1ph[i].ciphone),
bin_mdef_pid2tmatid(ps_search_acmod(ngs)->mdef, ngs->rhmm_1ph[i].ciphone));
ngs->rhmm_1ph[i].next = NULL;
ngs->word_chan[w] = (chan_t *) &(ngs->rhmm_1ph[i]);
i++;
}
ngs->single_phone_wid = ckd_calloc(ngs->n_1ph_words,
sizeof(*ngs->single_phone_wid));
E_INFO("%d root, %d non-root channels, %d single-phone words\n",
ngs->n_root_chan, ngs->n_nonroot_chan, ngs->n_1ph_words);
}
/*
* One-time initialization of internal channels in HMM tree.
*/
static void
init_nonroot_chan(ngram_search_t *ngs, chan_t * hmm, int32 ph, int32 ci, int32 tmatid)
{
hmm->next = NULL;
hmm->alt = NULL;
hmm->info.penult_phn_wid = -1;
hmm->ciphone = ci;
hmm_init(ngs->hmmctx, &hmm->hmm, FALSE, ph, tmatid);
}
/*
* Allocate and initialize search channel-tree structure.
* At this point, all the root-channels have been allocated and partly initialized
* (as per init_search_tree()), and channels for all the single-phone words have been
* allocated and initialized. None of the interior channels of search-trees have
* been allocated.
* This routine may be called on every utterance, after reinit_search_tree() clears
* the search tree created for the previous utterance. Meant for reconfiguring the
* search tree to suit the currently active LM.
*/
static void
create_search_tree(ngram_search_t *ngs)
{
chan_t *hmm;
root_chan_t *rhmm;
int32 w, i, j, p, ph, tmatid;
int32 n_words;
dict_t *dict = ps_search_dict(ngs);
dict2pid_t *d2p = ps_search_dict2pid(ngs);
n_words = ps_search_n_words(ngs);
E_INFO("Creating search tree\n");
for (w = 0; w < n_words; w++)
ngs->homophone_set[w] = -1;
E_INFO("before: %d root, %d non-root channels, %d single-phone words\n",
ngs->n_root_chan, ngs->n_nonroot_chan, ngs->n_1ph_words);
ngs->n_1ph_LMwords = 0;
ngs->n_root_chan = 0;
ngs->n_nonroot_chan = 0;
for (w = 0; w < n_words; w++) {
int ciphone, ci2phone;
/* Ignore dictionary words not in LM */
if (!ngram_model_set_known_wid(ngs->lmset, dict_basewid(dict, w)))
continue;
/* Handle single-phone words individually; not in channel tree */
if (dict_is_single_phone(dict, w)) {
E_DEBUG(1,("single_phone_wid[%d] = %s\n",
ngs->n_1ph_LMwords, dict_wordstr(dict, w)));
ngs->single_phone_wid[ngs->n_1ph_LMwords++] = w;
continue;
}
/* Find a root channel matching the initial diphone, or
* allocate one if not found. */
ciphone = dict_first_phone(dict, w);
ci2phone = dict_second_phone(dict, w);
for (i = 0; i < ngs->n_root_chan; ++i) {
if (ngs->root_chan[i].ciphone == ciphone
&& ngs->root_chan[i].ci2phone == ci2phone)
break;
}
if (i == ngs->n_root_chan) {
rhmm = &(ngs->root_chan[ngs->n_root_chan]);
rhmm->hmm.tmatid = bin_mdef_pid2tmatid(ps_search_acmod(ngs)->mdef, ciphone);
/* Begin with CI phone? Not sure this makes a difference... */
hmm_mpx_ssid(&rhmm->hmm, 0) =
bin_mdef_pid2ssid(ps_search_acmod(ngs)->mdef, ciphone);
rhmm->ciphone = ciphone;
rhmm->ci2phone = ci2phone;
ngs->n_root_chan++;
}
else
rhmm = &(ngs->root_chan[i]);
E_DEBUG(3,("word %s rhmm %d\n", dict_wordstr(dict, w), rhmm - ngs->root_chan));
/* Now, rhmm = root channel for w. Go on to remaining phones */
if (dict_pronlen(dict, w) == 2) {
/* Next phone is the last; not kept in tree; add w to penult_phn_wid set */
if ((j = rhmm->penult_phn_wid) < 0)
rhmm->penult_phn_wid = w;
else {
for (; ngs->homophone_set[j] >= 0; j = ngs->homophone_set[j]);
ngs->homophone_set[j] = w;
}
}
else {
/* Add remaining phones, except the last, to tree */
ph = dict2pid_internal(d2p, w, 1);
tmatid = bin_mdef_pid2tmatid(ps_search_acmod(ngs)->mdef, dict_pron(dict, w, 1));
hmm = rhmm->next;
if (hmm == NULL) {
rhmm->next = hmm = listelem_malloc(ngs->chan_alloc);
init_nonroot_chan(ngs, hmm, ph, dict_pron(dict, w, 1), tmatid);
ngs->n_nonroot_chan++;
}
else {
chan_t *prev_hmm = NULL;
for (; hmm && (hmm_nonmpx_ssid(&hmm->hmm) != ph); hmm = hmm->alt)
prev_hmm = hmm;
if (!hmm) { /* thanks, rkm! */
prev_hmm->alt = hmm = listelem_malloc(ngs->chan_alloc);
init_nonroot_chan(ngs, hmm, ph, dict_pron(dict, w, 1), tmatid);
ngs->n_nonroot_chan++;
}
}
E_DEBUG(3,("phone %s = %d\n",
bin_mdef_ciphone_str(ps_search_acmod(ngs)->mdef,
dict_second_phone(dict, w)), ph));
for (p = 2; p < dict_pronlen(dict, w) - 1; p++) {
ph = dict2pid_internal(d2p, w, p);
tmatid = bin_mdef_pid2tmatid(ps_search_acmod(ngs)->mdef, dict_pron(dict, w, p));
if (!hmm->next) {
hmm->next = listelem_malloc(ngs->chan_alloc);
hmm = hmm->next;
init_nonroot_chan(ngs, hmm, ph, dict_pron(dict, w, p), tmatid);
ngs->n_nonroot_chan++;
}
else {
chan_t *prev_hmm = NULL;
for (hmm = hmm->next; hmm && (hmm_nonmpx_ssid(&hmm->hmm) != ph);
hmm = hmm->alt)
prev_hmm = hmm;
if (!hmm) { /* thanks, rkm! */
prev_hmm->alt = hmm = listelem_malloc(ngs->chan_alloc);
init_nonroot_chan(ngs, hmm, ph, dict_pron(dict, w, p), tmatid);
ngs->n_nonroot_chan++;
}
}
E_DEBUG(3,("phone %s = %d\n",
bin_mdef_ciphone_str(ps_search_acmod(ngs)->mdef,
dict_pron(dict, w, p)), ph));
}
/* All but last phone of w in tree; add w to hmm->info.penult_phn_wid set */
if ((j = hmm->info.penult_phn_wid) < 0)
hmm->info.penult_phn_wid = w;
else {
for (; ngs->homophone_set[j] >= 0; j = ngs->homophone_set[j]);
ngs->homophone_set[j] = w;
}
}
}
ngs->n_1ph_words = ngs->n_1ph_LMwords;
/* Add filler words to the array of 1ph words. */
for (w = 0; w < n_words; ++w) {
/* Skip anything that doesn't actually have a single phone. */
if (!dict_is_single_phone(dict, w))
continue;
/* Also skip "real words" and things that are in the LM. */
if (dict_real_word(dict, w))
continue;
if (ngram_model_set_known_wid(ngs->lmset, dict_basewid(dict, w)))
continue;
E_DEBUG(1,("single_phone_wid[%d] = %s\n",
ngs->n_1ph_words, dict_wordstr(dict, w)));
ngs->single_phone_wid[ngs->n_1ph_words++] = w;
}
if (ngs->n_nonroot_chan >= ngs->max_nonroot_chan) {
/* Give some room for channels for new words added dynamically at run time */
ngs->max_nonroot_chan = ngs->n_nonroot_chan + 128;
E_INFO("after: max nonroot chan increased to %d\n", ngs->max_nonroot_chan);
/* Free old active channel list array if any and allocate new one */
if (ngs->active_chan_list)
ckd_free_2d(ngs->active_chan_list);
ngs->active_chan_list = ckd_calloc_2d(2, ngs->max_nonroot_chan,
sizeof(**ngs->active_chan_list));
}
if (!ngs->n_root_chan)
E_ERROR("No word from the language model has pronunciation in the dictionary\n");
E_INFO("after: %d root, %d non-root channels, %d single-phone words\n",
ngs->n_root_chan, ngs->n_nonroot_chan, ngs->n_1ph_words);
}
static void
reinit_search_subtree(ngram_search_t *ngs, chan_t * hmm)
{
chan_t *child, *sibling;
/* First free all children under hmm */
for (child = hmm->next; child; child = sibling) {
sibling = child->alt;
reinit_search_subtree(ngs, child);
}
/* Now free hmm */
hmm_deinit(&hmm->hmm);
listelem_free(ngs->chan_alloc, hmm);
}
/*
* Delete search tree by freeing all interior channels within search tree and
* restoring root channel state to the init state (i.e., just after init_search_tree()).
*/
static void
reinit_search_tree(ngram_search_t *ngs)
{
int32 i;
chan_t *hmm, *sibling;
for (i = 0; i < ngs->n_root_chan; i++) {
hmm = ngs->root_chan[i].next;
while (hmm) {
sibling = hmm->alt;
reinit_search_subtree(ngs, hmm);
hmm = sibling;
}
ngs->root_chan[i].penult_phn_wid = -1;
ngs->root_chan[i].next = NULL;
}
ngs->n_nonroot_chan = 0;
}
void
ngram_fwdtree_init(ngram_search_t *ngs)
{
/* Allocate bestbp_rc, lastphn_cand, last_ltrans */
ngs->bestbp_rc = ckd_calloc(bin_mdef_n_ciphone(ps_search_acmod(ngs)->mdef),
sizeof(*ngs->bestbp_rc));
ngs->lastphn_cand = ckd_calloc(ps_search_n_words(ngs),
sizeof(*ngs->lastphn_cand));
init_search_tree(ngs);
create_search_tree(ngs);
}
static void
deinit_search_tree(ngram_search_t *ngs)
{
int i, w, n_words;
n_words = ps_search_n_words(ngs);
for (i = 0; i < ngs->n_root_chan_alloc; i++) {
hmm_deinit(&ngs->root_chan[i].hmm);
}
if (ngs->rhmm_1ph) {
for (i = w = 0; w < n_words; ++w) {
if (!dict_is_single_phone(ps_search_dict(ngs), w))
continue;
hmm_deinit(&ngs->rhmm_1ph[i].hmm);
++i;
}
ckd_free(ngs->rhmm_1ph);
ngs->rhmm_1ph = NULL;
}
ngs->n_root_chan = 0;
ngs->n_root_chan_alloc = 0;
ckd_free(ngs->root_chan);
ngs->root_chan = NULL;
ckd_free(ngs->single_phone_wid);
ngs->single_phone_wid = NULL;
ckd_free(ngs->homophone_set);
ngs->homophone_set = NULL;
}
void
ngram_fwdtree_deinit(ngram_search_t *ngs)
{
double n_speech = (double)ngs->n_tot_frame
/ cmd_ln_int32_r(ps_search_config(ngs), "-frate");
E_INFO("TOTAL fwdtree %.2f CPU %.3f xRT\n",
ngs->fwdtree_perf.t_tot_cpu,
ngs->fwdtree_perf.t_tot_cpu / n_speech);
E_INFO("TOTAL fwdtree %.2f wall %.3f xRT\n",
ngs->fwdtree_perf.t_tot_elapsed,
ngs->fwdtree_perf.t_tot_elapsed / n_speech);
/* Reset non-root channels. */
reinit_search_tree(ngs);
/* Free the search tree. */
deinit_search_tree(ngs);
/* Free other stuff. */
ngs->max_nonroot_chan = 0;
ckd_free_2d(ngs->active_chan_list);
ngs->active_chan_list = NULL;
ckd_free(ngs->cand_sf);
ngs->cand_sf = NULL;
ckd_free(ngs->bestbp_rc);
ngs->bestbp_rc = NULL;
ckd_free(ngs->lastphn_cand);
ngs->lastphn_cand = NULL;
}
int
ngram_fwdtree_reinit(ngram_search_t *ngs)
{
/* Reset non-root channels. */
reinit_search_tree(ngs);
/* Free the search tree. */
deinit_search_tree(ngs);
/* Reallocate things that depend on the number of words. */
ckd_free(ngs->lastphn_cand);
ngs->lastphn_cand = ckd_calloc(ps_search_n_words(ngs),
sizeof(*ngs->lastphn_cand));
ckd_free(ngs->word_chan);
ngs->word_chan = ckd_calloc(ps_search_n_words(ngs),
sizeof(*ngs->word_chan));
/* Rebuild the search tree. */
init_search_tree(ngs);
create_search_tree(ngs);
return 0;
}
void
ngram_fwdtree_start(ngram_search_t *ngs)
{
ps_search_t *base = (ps_search_t *)ngs;
int32 i, w, n_words;
root_chan_t *rhmm;
n_words = ps_search_n_words(ngs);
/* Reset utterance statistics. */
memset(&ngs->st, 0, sizeof(ngs->st));
ptmr_reset(&ngs->fwdtree_perf);
ptmr_start(&ngs->fwdtree_perf);
/* Reset backpointer table. */
ngs->bpidx = 0;
ngs->bss_head = 0;
/* Reset word lattice. */
for (i = 0; i < n_words; ++i)
ngs->word_lat_idx[i] = NO_BP;
/* Reset active HMM and word lists. */
ngs->n_active_chan[0] = ngs->n_active_chan[1] = 0;
ngs->n_active_word[0] = ngs->n_active_word[1] = 0;
/* Reset scores. */
ngs->best_score = 0;
ngs->renormalized = 0;
/* Reset other stuff. */
for (i = 0; i < n_words; i++)
ngs->last_ltrans[i].sf = -1;
ngs->n_frame = 0;
/* Clear the hypothesis string. */
ckd_free(base->hyp_str);
base->hyp_str = NULL;
/* Reset the permanently allocated single-phone words, since they
* may have junk left over in them from FWDFLAT. */
for (i = 0; i < ngs->n_1ph_words; i++) {
w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
hmm_clear(&rhmm->hmm);
}
/* Start search with <s>; word_chan[<s>] is permanently allocated */
rhmm = (root_chan_t *) ngs->word_chan[dict_startwid(ps_search_dict(ngs))];
hmm_clear(&rhmm->hmm);
hmm_enter(&rhmm->hmm, 0, NO_BP, 0);
}
/*
* Mark the active senones for all senones belonging to channels that are active in the
* current frame.
*/
static void
compute_sen_active(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
chan_t *hmm, **acl;
int32 i, w, *awl;
acmod_clear_active(ps_search_acmod(ngs));
/* Flag active senones for root channels */
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
if (hmm_frame(&rhmm->hmm) == frame_idx)
acmod_activate_hmm(ps_search_acmod(ngs), &rhmm->hmm);
}
/* Flag active senones for nonroot channels in HMM tree */
i = ngs->n_active_chan[frame_idx & 0x1];
acl = ngs->active_chan_list[frame_idx & 0x1];
for (hmm = *(acl++); i > 0; --i, hmm = *(acl++)) {
acmod_activate_hmm(ps_search_acmod(ngs), &hmm->hmm);
}
/* Flag active senones for individual word channels */
i = ngs->n_active_word[frame_idx & 0x1];
awl = ngs->active_word_list[frame_idx & 0x1];
for (w = *(awl++); i > 0; --i, w = *(awl++)) {
for (hmm = ngs->word_chan[w]; hmm; hmm = hmm->next) {
acmod_activate_hmm(ps_search_acmod(ngs), &hmm->hmm);
}
}
for (i = 0; i < ngs->n_1ph_words; i++) {
w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
if (hmm_frame(&rhmm->hmm) == frame_idx)
acmod_activate_hmm(ps_search_acmod(ngs), &rhmm->hmm);
}
}
static void
renormalize_scores(ngram_search_t *ngs, int frame_idx, int32 norm)
{
root_chan_t *rhmm;
chan_t *hmm, **acl;
int32 i, w, *awl;
/* Renormalize root channels */
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
if (hmm_frame(&rhmm->hmm) == frame_idx) {
hmm_normalize(&rhmm->hmm, norm);
}
}
/* Renormalize nonroot channels in HMM tree */
i = ngs->n_active_chan[frame_idx & 0x1];
acl = ngs->active_chan_list[frame_idx & 0x1];
for (hmm = *(acl++); i > 0; --i, hmm = *(acl++)) {
hmm_normalize(&hmm->hmm, norm);
}
/* Renormalize individual word channels */
i = ngs->n_active_word[frame_idx & 0x1];
awl = ngs->active_word_list[frame_idx & 0x1];
for (w = *(awl++); i > 0; --i, w = *(awl++)) {
for (hmm = ngs->word_chan[w]; hmm; hmm = hmm->next) {
hmm_normalize(&hmm->hmm, norm);
}
}
for (i = 0; i < ngs->n_1ph_words; i++) {
w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
if (hmm_frame(&rhmm->hmm) == frame_idx) {
hmm_normalize(&rhmm->hmm, norm);
}
}
ngs->renormalized = TRUE;
}
static int32
eval_root_chan(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
int32 i, bestscore;
bestscore = WORST_SCORE;
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
if (hmm_frame(&rhmm->hmm) == frame_idx) {
int32 score = chan_v_eval(rhmm);
if (score BETTER_THAN bestscore)
bestscore = score;
++ngs->st.n_root_chan_eval;
}
}
return (bestscore);
}
static int32
eval_nonroot_chan(ngram_search_t *ngs, int frame_idx)
{
chan_t *hmm, **acl;
int32 i, bestscore;
i = ngs->n_active_chan[frame_idx & 0x1];
acl = ngs->active_chan_list[frame_idx & 0x1];
bestscore = WORST_SCORE;
ngs->st.n_nonroot_chan_eval += i;
for (hmm = *(acl++); i > 0; --i, hmm = *(acl++)) {
int32 score = chan_v_eval(hmm);
assert(hmm_frame(&hmm->hmm) == frame_idx);
if (score BETTER_THAN bestscore)
bestscore = score;
}
return bestscore;
}
static int32
eval_word_chan(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
chan_t *hmm;
int32 i, w, bestscore, *awl, j, k;
k = 0;
bestscore = WORST_SCORE;
awl = ngs->active_word_list[frame_idx & 0x1];
i = ngs->n_active_word[frame_idx & 0x1];
for (w = *(awl++); i > 0; --i, w = *(awl++)) {
assert(bitvec_is_set(ngs->word_active, w));
bitvec_clear(ngs->word_active, w);
assert(ngs->word_chan[w] != NULL);
for (hmm = ngs->word_chan[w]; hmm; hmm = hmm->next) {
int32 score;
assert(hmm_frame(&hmm->hmm) == frame_idx);
score = chan_v_eval(hmm);
/*printf("eval word chan %d score %d\n", w, score); */
if (score BETTER_THAN bestscore)
bestscore = score;
k++;
}
}
/* Similarly for statically allocated single-phone words */
j = 0;
for (i = 0; i < ngs->n_1ph_words; i++) {
int32 score;
w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
if (hmm_frame(&rhmm->hmm) < frame_idx)
continue;
score = chan_v_eval(rhmm);
/* printf("eval 1ph word chan %d score %d\n", w, score); */
if (score BETTER_THAN bestscore && w != ps_search_finish_wid(ngs))
bestscore = score;
j++;
}
ngs->st.n_last_chan_eval += k + j;
ngs->st.n_nonroot_chan_eval += k + j;
ngs->st.n_word_lastchan_eval +=
ngs->n_active_word[frame_idx & 0x1] + j;
return bestscore;
}
static int32
evaluate_channels(ngram_search_t *ngs, int16 const *senone_scores, int frame_idx)
{
int32 bs;
hmm_context_set_senscore(ngs->hmmctx, senone_scores);
ngs->best_score = eval_root_chan(ngs, frame_idx);
if ((bs = eval_nonroot_chan(ngs, frame_idx)) BETTER_THAN ngs->best_score)
ngs->best_score = bs;
if ((bs = eval_word_chan(ngs, frame_idx)) BETTER_THAN ngs->best_score)
ngs->best_score = bs;
ngs->last_phone_best_score = bs;
return ngs->best_score;
}
/*
* Prune currently active root channels for next frame. Also, perform exit
* transitions out of them and activate successors.
* score[] of pruned root chan set to WORST_SCORE elsewhere.
*/
static void
prune_root_chan(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
chan_t *hmm;
int32 i, nf, w;
int32 thresh, newphone_thresh, lastphn_thresh, newphone_score;
chan_t **nacl; /* next active list */
lastphn_cand_t *candp;
phone_loop_search_t *pls;
nf = frame_idx + 1;
thresh = ngs->best_score + ngs->dynamic_beam;
newphone_thresh = ngs->best_score + ngs->pbeam;
lastphn_thresh = ngs->best_score + ngs->lpbeam;
nacl = ngs->active_chan_list[nf & 0x1];
pls = (phone_loop_search_t *)ps_search_lookahead(ngs);
for (i = 0, rhmm = ngs->root_chan; i < ngs->n_root_chan; i++, rhmm++) {
E_DEBUG(3,("Root channel %d frame %d score %d thresh %d\n",
i, hmm_frame(&rhmm->hmm), hmm_bestscore(&rhmm->hmm), thresh));
/* First check if this channel was active in current frame */
if (hmm_frame(&rhmm->hmm) < frame_idx)
continue;
if (hmm_bestscore(&rhmm->hmm) BETTER_THAN thresh) {
hmm_frame(&rhmm->hmm) = nf; /* rhmm will be active in next frame */
E_DEBUG(3,("Preserving root channel %d score %d\n", i, hmm_bestscore(&rhmm->hmm)));
/* transitions out of this root channel */
/* transition to all next-level channels in the HMM tree */
newphone_score = hmm_out_score(&rhmm->hmm) + ngs->pip;
if (pls != NULL || newphone_score BETTER_THAN newphone_thresh) {
for (hmm = rhmm->next; hmm; hmm = hmm->alt) {
int32 pl_newphone_score = newphone_score
+ phone_loop_search_score(pls, hmm->ciphone);
if (pl_newphone_score BETTER_THAN newphone_thresh) {
if ((hmm_frame(&hmm->hmm) < frame_idx)
|| (newphone_score BETTER_THAN hmm_in_score(&hmm->hmm))) {
hmm_enter(&hmm->hmm, newphone_score,
hmm_out_history(&rhmm->hmm), nf);
*(nacl++) = hmm;
}
}
}
}
/*
* Transition to last phone of all words for which this is the
* penultimate phone (the last phones may need multiple right contexts).
* Remember to remove the temporary newword_penalty.
*/
if (pls != NULL || newphone_score BETTER_THAN lastphn_thresh) {
for (w = rhmm->penult_phn_wid; w >= 0;
w = ngs->homophone_set[w]) {
int32 pl_newphone_score = newphone_score
+ phone_loop_search_score
(pls, dict_last_phone(ps_search_dict(ngs),w));
E_DEBUG(3,("word %s newphone_score %d\n", dict_wordstr(ps_search_dict(ngs), w), newphone_score));
if (pl_newphone_score BETTER_THAN lastphn_thresh) {
candp = ngs->lastphn_cand + ngs->n_lastphn_cand;
ngs->n_lastphn_cand++;
candp->wid = w;
candp->score =
newphone_score - ngs->nwpen;
candp->bp = hmm_out_history(&rhmm->hmm);
}
}
}
}
}
ngs->n_active_chan[nf & 0x1] = (int)(nacl - ngs->active_chan_list[nf & 0x1]);
}
/*
* Prune currently active nonroot channels in HMM tree for next frame. Also, perform
* exit transitions out of such channels and activate successors.
*/
static void
prune_nonroot_chan(ngram_search_t *ngs, int frame_idx)
{
chan_t *hmm, *nexthmm;
int32 nf, w, i;
int32 thresh, newphone_thresh, lastphn_thresh, newphone_score;
chan_t **acl, **nacl; /* active list, next active list */
lastphn_cand_t *candp;
phone_loop_search_t *pls;
nf = frame_idx + 1;
thresh = ngs->best_score + ngs->dynamic_beam;
newphone_thresh = ngs->best_score + ngs->pbeam;
lastphn_thresh = ngs->best_score + ngs->lpbeam;
pls = (phone_loop_search_t *)ps_search_lookahead(ngs);
acl = ngs->active_chan_list[frame_idx & 0x1]; /* currently active HMMs in tree */
nacl = ngs->active_chan_list[nf & 0x1] + ngs->n_active_chan[nf & 0x1];
for (i = ngs->n_active_chan[frame_idx & 0x1], hmm = *(acl++); i > 0;
--i, hmm = *(acl++)) {
assert(hmm_frame(&hmm->hmm) >= frame_idx);
if (hmm_bestscore(&hmm->hmm) BETTER_THAN thresh) {
/* retain this channel in next frame */
if (hmm_frame(&hmm->hmm) != nf) {
hmm_frame(&hmm->hmm) = nf;
*(nacl++) = hmm;
}
/* transition to all next-level channel in the HMM tree */
newphone_score = hmm_out_score(&hmm->hmm) + ngs->pip;
if (pls != NULL || newphone_score BETTER_THAN newphone_thresh) {
for (nexthmm = hmm->next; nexthmm; nexthmm = nexthmm->alt) {
int32 pl_newphone_score = newphone_score
+ phone_loop_search_score(pls, nexthmm->ciphone);
if ((pl_newphone_score BETTER_THAN newphone_thresh)
&& ((hmm_frame(&nexthmm->hmm) < frame_idx)
|| (newphone_score
BETTER_THAN hmm_in_score(&nexthmm->hmm)))) {
if (hmm_frame(&nexthmm->hmm) != nf) {
/* Keep this HMM on the active list */
*(nacl++) = nexthmm;
}
hmm_enter(&nexthmm->hmm, newphone_score,
hmm_out_history(&hmm->hmm), nf);
}
}
}
/*
* Transition to last phone of all words for which this is the
* penultimate phone (the last phones may need multiple right contexts).
* Remember to remove the temporary newword_penalty.
*/
if (pls != NULL || newphone_score BETTER_THAN lastphn_thresh) {
for (w = hmm->info.penult_phn_wid; w >= 0;
w = ngs->homophone_set[w]) {
int32 pl_newphone_score = newphone_score
+ phone_loop_search_score
(pls, dict_last_phone(ps_search_dict(ngs),w));
if (pl_newphone_score BETTER_THAN lastphn_thresh) {
candp = ngs->lastphn_cand + ngs->n_lastphn_cand;
ngs->n_lastphn_cand++;
candp->wid = w;
candp->score =
newphone_score - ngs->nwpen;
candp->bp = hmm_out_history(&hmm->hmm);
}
}
}
}
else if (hmm_frame(&hmm->hmm) != nf) {
hmm_clear(&hmm->hmm);
}
}
ngs->n_active_chan[nf & 0x1] = (int)(nacl - ngs->active_chan_list[nf & 0x1]);
}
/*
* Execute the transition into the last phone for all candidates words emerging from
* the HMM tree. Attach LM scores to such transitions.
* (Executed after pruning root and non-root, but before pruning word-chan.)
*/
static void
last_phone_transition(ngram_search_t *ngs, int frame_idx)
{
int32 i, j, k, nf, bp, bpend, w;
lastphn_cand_t *candp;
int32 *nawl;
int32 thresh;
int32 bestscore, dscr;
chan_t *hmm;
bptbl_t *bpe;
int32 n_cand_sf = 0;
nf = frame_idx + 1;
nawl = ngs->active_word_list[nf & 0x1];
ngs->st.n_lastphn_cand_utt += ngs->n_lastphn_cand;
/* For each candidate word (entering its last phone) */
/* If best LM score and bp for candidate known use it, else sort cands by startfrm */
for (i = 0, candp = ngs->lastphn_cand; i < ngs->n_lastphn_cand; i++, candp++) {
int32 start_score;
/* This can happen if recognition fails. */
if (candp->bp == -1)
continue;
/* Backpointer entry for it. */
bpe = &(ngs->bp_table[candp->bp]);
/* Subtract starting score for candidate, leave it with only word score */
start_score = ngram_search_exit_score
(ngs, bpe, dict_first_phone(ps_search_dict(ngs), candp->wid));
assert(start_score BETTER_THAN WORST_SCORE);
candp->score -= start_score;
/*
* If this candidate not occurred in an earlier frame, prepare for finding
* best transition score into last phone; sort by start frame.
*/
/* i.e. if we don't have an entry in last_ltrans for this
* <word,sf>, then create one */
if (ngs->last_ltrans[candp->wid].sf != bpe->frame + 1) {
/* Look for an entry in cand_sf matching the backpointer
* for this candidate. */
for (j = 0; j < n_cand_sf; j++) {
if (ngs->cand_sf[j].bp_ef == bpe->frame)
break;
}
/* Oh, we found one, so chain onto it. */
if (j < n_cand_sf)
candp->next = ngs->cand_sf[j].cand;
else {
/* Nope, let's make a new one, allocating cand_sf if necessary. */
if (n_cand_sf >= ngs->cand_sf_alloc) {
if (ngs->cand_sf_alloc == 0) {
ngs->cand_sf =
ckd_calloc(CAND_SF_ALLOCSIZE,
sizeof(*ngs->cand_sf));
ngs->cand_sf_alloc = CAND_SF_ALLOCSIZE;
}
else {
ngs->cand_sf_alloc += CAND_SF_ALLOCSIZE;
ngs->cand_sf = ckd_realloc(ngs->cand_sf,
ngs->cand_sf_alloc
* sizeof(*ngs->cand_sf));
E_INFO("cand_sf[] increased to %d entries\n",
ngs->cand_sf_alloc);
}
}
/* Use the newly created cand_sf. */
j = n_cand_sf++;
candp->next = -1; /* End of the chain. */
ngs->cand_sf[j].bp_ef = bpe->frame;
}
/* Update it to point to this candidate. */
ngs->cand_sf[j].cand = i;
ngs->last_ltrans[candp->wid].dscr = WORST_SCORE;
ngs->last_ltrans[candp->wid].sf = bpe->frame + 1;
}
}
/* Compute best LM score and bp for new cands entered in the sorted lists above */
for (i = 0; i < n_cand_sf; i++) {
/* For the i-th unique end frame... */
bp = ngs->bp_table_idx[ngs->cand_sf[i].bp_ef];
bpend = ngs->bp_table_idx[ngs->cand_sf[i].bp_ef + 1];
for (bpe = &(ngs->bp_table[bp]); bp < bpend; bp++, bpe++) {
if (!bpe->valid)
continue;
/* For each candidate at the start frame find bp->cand transition-score */
for (j = ngs->cand_sf[i].cand; j >= 0; j = candp->next) {
int32 n_used;
candp = &(ngs->lastphn_cand[j]);
dscr =
ngram_search_exit_score
(ngs, bpe, dict_first_phone(ps_search_dict(ngs), candp->wid));
if (dscr BETTER_THAN WORST_SCORE) {
assert(!dict_filler_word(ps_search_dict(ngs), candp->wid));
dscr += ngram_tg_score(ngs->lmset,
dict_basewid(ps_search_dict(ngs), candp->wid),
bpe->real_wid,
bpe->prev_real_wid,
&n_used)>>SENSCR_SHIFT;
}
if (dscr BETTER_THAN ngs->last_ltrans[candp->wid].dscr) {
ngs->last_ltrans[candp->wid].dscr = dscr;
ngs->last_ltrans[candp->wid].bp = bp;
}
}
}
}
/* Update best transitions for all candidates; also update best lastphone score */
bestscore = ngs->last_phone_best_score;
for (i = 0, candp = ngs->lastphn_cand; i < ngs->n_lastphn_cand; i++, candp++) {
candp->score += ngs->last_ltrans[candp->wid].dscr;
candp->bp = ngs->last_ltrans[candp->wid].bp;
if (candp->score BETTER_THAN bestscore)
bestscore = candp->score;
}
ngs->last_phone_best_score = bestscore;
/* At this pt, we know the best entry score (with LM component) for all candidates */
thresh = bestscore + ngs->lponlybeam;
for (i = ngs->n_lastphn_cand, candp = ngs->lastphn_cand; i > 0; --i, candp++) {
if (candp->score BETTER_THAN thresh) {
w = candp->wid;
ngram_search_alloc_all_rc(ngs, w);
k = 0;
for (hmm = ngs->word_chan[w]; hmm; hmm = hmm->next) {
if ((hmm_frame(&hmm->hmm) < frame_idx)
|| (candp->score BETTER_THAN hmm_in_score(&hmm->hmm))) {
assert(hmm_frame(&hmm->hmm) != nf);
hmm_enter(&hmm->hmm,
candp->score, candp->bp, nf);
k++;
}
}
if (k > 0) {
assert(bitvec_is_clear(ngs->word_active, w));
assert(!dict_is_single_phone(ps_search_dict(ngs), w));
*(nawl++) = w;
bitvec_set(ngs->word_active, w);
}
}
}
ngs->n_active_word[nf & 0x1] = (int)(nawl - ngs->active_word_list[nf & 0x1]);
}
/*
* Prune currently active word channels for next frame. Also, perform exit
* transitions out of such channels and active successors.
*/
static void
prune_word_chan(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
chan_t *hmm, *thmm;
chan_t **phmmp; /* previous HMM-pointer */
int32 nf, w, i, k;
int32 newword_thresh, lastphn_thresh;
int32 *awl, *nawl;
nf = frame_idx + 1;
newword_thresh = ngs->last_phone_best_score + ngs->wbeam;
lastphn_thresh = ngs->last_phone_best_score + ngs->lponlybeam;
awl = ngs->active_word_list[frame_idx & 0x1];
nawl = ngs->active_word_list[nf & 0x1] + ngs->n_active_word[nf & 0x1];
/* Dynamically allocated last channels of multi-phone words */
for (i = ngs->n_active_word[frame_idx & 0x1], w = *(awl++); i > 0;
--i, w = *(awl++)) {
k = 0;
phmmp = &(ngs->word_chan[w]);
for (hmm = ngs->word_chan[w]; hmm; hmm = thmm) {
assert(hmm_frame(&hmm->hmm) >= frame_idx);
thmm = hmm->next;
if (hmm_bestscore(&hmm->hmm) BETTER_THAN lastphn_thresh) {
/* retain this channel in next frame */
hmm_frame(&hmm->hmm) = nf;
k++;
phmmp = &(hmm->next);
/* Could if ((! skip_alt_frm) || (frame_idx & 0x1)) the following */
if (hmm_out_score(&hmm->hmm) BETTER_THAN newword_thresh) {
/* can exit channel and recognize word */
ngram_search_save_bp(ngs, frame_idx, w,
hmm_out_score(&hmm->hmm),
hmm_out_history(&hmm->hmm),
hmm->info.rc_id);
}
}
else if (hmm_frame(&hmm->hmm) == nf) {
phmmp = &(hmm->next);
}
else {
hmm_deinit(&hmm->hmm);
listelem_free(ngs->chan_alloc, hmm);
*phmmp = thmm;
}
}
if ((k > 0) && (bitvec_is_clear(ngs->word_active, w))) {
assert(!dict_is_single_phone(ps_search_dict(ngs), w));
*(nawl++) = w;
bitvec_set(ngs->word_active, w);
}
}
ngs->n_active_word[nf & 0x1] = (int)(nawl - ngs->active_word_list[nf & 0x1]);
/*
* Prune permanently allocated single-phone channels.
* NOTES: score[] of pruned channels set to WORST_SCORE elsewhere.
*/
for (i = 0; i < ngs->n_1ph_words; i++) {
w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
E_DEBUG(3,("Single phone word %s frame %d score %d thresh %d outscore %d nwthresh %d\n",
dict_wordstr(ps_search_dict(ngs),w),
hmm_frame(&rhmm->hmm), hmm_bestscore(&rhmm->hmm),
lastphn_thresh, hmm_out_score(&rhmm->hmm), newword_thresh));
if (hmm_frame(&rhmm->hmm) < frame_idx)
continue;
if (hmm_bestscore(&rhmm->hmm) BETTER_THAN lastphn_thresh) {
hmm_frame(&rhmm->hmm) = nf;
/* Could if ((! skip_alt_frm) || (frame_idx & 0x1)) the following */
if (hmm_out_score(&rhmm->hmm) BETTER_THAN newword_thresh) {
E_DEBUG(4,("Exiting single phone word %s with %d > %d, %d\n",
dict_wordstr(ps_search_dict(ngs),w),
hmm_out_score(&rhmm->hmm),
lastphn_thresh, newword_thresh));
ngram_search_save_bp(ngs, frame_idx, w,
hmm_out_score(&rhmm->hmm),
hmm_out_history(&rhmm->hmm), 0);
}
}
}
}
static void
prune_channels(ngram_search_t *ngs, int frame_idx)
{
/* Clear last phone candidate list. */
ngs->n_lastphn_cand = 0;
/* Set the dynamic beam based on maxhmmpf here. */
ngs->dynamic_beam = ngs->beam;
if (ngs->maxhmmpf != -1
&& ngs->st.n_root_chan_eval + ngs->st.n_nonroot_chan_eval > ngs->maxhmmpf) {
/* Build a histogram to approximately prune them. */
int32 bins[256], bw, nhmms, i;
root_chan_t *rhmm;
chan_t **acl, *hmm;
/* Bins go from zero (best score) to edge of beam. */
bw = -ngs->beam / 256;
memset(bins, 0, sizeof(bins));
/* For each active root channel. */
for (i = 0, rhmm = ngs->root_chan; i < ngs->n_root_chan; i++, rhmm++) {
int32 b;
/* Put it in a bin according to its bestscore. */
b = (ngs->best_score - hmm_bestscore(&rhmm->hmm)) / bw;
if (b >= 256)
b = 255;
++bins[b];
}
/* For each active non-root channel. */
acl = ngs->active_chan_list[frame_idx & 0x1]; /* currently active HMMs in tree */
for (i = ngs->n_active_chan[frame_idx & 0x1], hmm = *(acl++);
i > 0; --i, hmm = *(acl++)) {
int32 b;
/* Put it in a bin according to its bestscore. */
b = (ngs->best_score - hmm_bestscore(&hmm->hmm)) / bw;
if (b >= 256)
b = 255;
++bins[b];
}
/* Walk down the bins to find the new beam. */
for (i = nhmms = 0; i < 256; ++i) {
nhmms += bins[i];
if (nhmms > ngs->maxhmmpf)
break;
}
ngs->dynamic_beam = -(i * bw);
}
prune_root_chan(ngs, frame_idx);
prune_nonroot_chan(ngs, frame_idx);
last_phone_transition(ngs, frame_idx);
prune_word_chan(ngs, frame_idx);
}
/*
* Limit the number of word exits in each frame to maxwpf. And also limit the number of filler
* words to 1.
*/
static void
bptable_maxwpf(ngram_search_t *ngs, int frame_idx)
{
int32 bp, n;
int32 bestscr, worstscr;
bptbl_t *bpe, *bestbpe, *worstbpe;
/* Don't prune if no pruing. */
if (ngs->maxwpf == -1 || ngs->maxwpf == ps_search_n_words(ngs))
return;
/* Allow only one filler word exit (the best) per frame */
bestscr = (int32) 0x80000000;
bestbpe = NULL;
n = 0;
for (bp = ngs->bp_table_idx[frame_idx]; bp < ngs->bpidx; bp++) {
bpe = &(ngs->bp_table[bp]);
if (dict_filler_word(ps_search_dict(ngs), bpe->wid)) {
if (bpe->score BETTER_THAN bestscr) {
bestscr = bpe->score;
bestbpe = bpe;
}
bpe->valid = FALSE;
n++; /* No. of filler words */
}
}
/* Restore bestbpe to valid state */
if (bestbpe != NULL) {
bestbpe->valid = TRUE;
--n;
}
/* Allow up to maxwpf best entries to survive; mark the remaining with valid = 0 */
n = (ngs->bpidx
- ngs->bp_table_idx[frame_idx]) - n; /* No. of entries after limiting fillers */
for (; n > ngs->maxwpf; --n) {
/* Find worst BPTable entry */
worstscr = (int32) 0x7fffffff;
worstbpe = NULL;
for (bp = ngs->bp_table_idx[frame_idx]; (bp < ngs->bpidx); bp++) {
bpe = &(ngs->bp_table[bp]);
if (bpe->valid && (bpe->score WORSE_THAN worstscr)) {
worstscr = bpe->score;
worstbpe = bpe;
}
}
/* FIXME: Don't panic! */
if (worstbpe == NULL)
E_FATAL("PANIC: No worst BPtable entry remaining\n");
worstbpe->valid = FALSE;
}
}
static void
word_transition(ngram_search_t *ngs, int frame_idx)
{
int32 i, k, bp, w, nf;
int32 rc;
int32 thresh, newscore, pl_newscore;
bptbl_t *bpe;
root_chan_t *rhmm;
struct bestbp_rc_s *bestbp_rc_ptr;
phone_loop_search_t *pls;
dict_t *dict = ps_search_dict(ngs);
dict2pid_t *d2p = ps_search_dict2pid(ngs);
/*
* Transition to start of new word instances (HMM tree roots); but only if words
* other than </s> finished here.
* But, first, find the best starting score for each possible right context phone.
*/
for (i = bin_mdef_n_ciphone(ps_search_acmod(ngs)->mdef) - 1; i >= 0; --i)
ngs->bestbp_rc[i].score = WORST_SCORE;
k = 0;
pls = (phone_loop_search_t *)ps_search_lookahead(ngs);
/* Ugh, this is complicated. Scan all word exits for this frame
* (they have already been created by prune_word_chan()). */
for (bp = ngs->bp_table_idx[frame_idx]; bp < ngs->bpidx; bp++) {
bpe = &(ngs->bp_table[bp]);
ngs->word_lat_idx[bpe->wid] = NO_BP;
if (bpe->wid == ps_search_finish_wid(ngs))
continue;
k++;
/* DICT2PID */
/* Array of HMM scores corresponding to all the possible right
* context expansions of the final phone. It's likely that a
* lot of these are going to be missing, actually. */
if (bpe->last2_phone == -1) { /* implies s_idx == -1 */
/* No right context expansion. */
for (rc = 0; rc < bin_mdef_n_ciphone(ps_search_acmod(ngs)->mdef); ++rc) {
if (bpe->score BETTER_THAN ngs->bestbp_rc[rc].score) {
E_DEBUG(4,("bestbp_rc[0] = %d lc %d\n",
bpe->score, bpe->last_phone));
ngs->bestbp_rc[rc].score = bpe->score;
ngs->bestbp_rc[rc].path = bp;
ngs->bestbp_rc[rc].lc = bpe->last_phone;
}
}
}
else {
xwdssid_t *rssid = dict2pid_rssid(d2p, bpe->last_phone, bpe->last2_phone);
int32 *rcss = &(ngs->bscore_stack[bpe->s_idx]);
for (rc = 0; rc < bin_mdef_n_ciphone(ps_search_acmod(ngs)->mdef); ++rc) {
if (rcss[rssid->cimap[rc]] BETTER_THAN ngs->bestbp_rc[rc].score) {
E_DEBUG(4,("bestbp_rc[%d] = %d lc %d\n",
rc, rcss[rssid->cimap[rc]], bpe->last_phone));
ngs->bestbp_rc[rc].score = rcss[rssid->cimap[rc]];
ngs->bestbp_rc[rc].path = bp;
ngs->bestbp_rc[rc].lc = bpe->last_phone;
}
}
}
}
if (k == 0)
return;
nf = frame_idx + 1;
thresh = ngs->best_score + ngs->dynamic_beam;
/*
* Hypothesize successors to words finished in this frame.
* Main dictionary, multi-phone words transition to HMM-trees roots.
*/
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
bestbp_rc_ptr = &(ngs->bestbp_rc[rhmm->ciphone]);
newscore = bestbp_rc_ptr->score + ngs->nwpen + ngs->pip;
pl_newscore = newscore
+ phone_loop_search_score(pls, rhmm->ciphone);
if (pl_newscore BETTER_THAN thresh) {
if ((hmm_frame(&rhmm->hmm) < frame_idx)
|| (newscore BETTER_THAN hmm_in_score(&rhmm->hmm))) {
hmm_enter(&rhmm->hmm, newscore,
bestbp_rc_ptr->path, nf);
/* DICT2PID: Another place where mpx ssids are entered. */
/* Look up the ssid to use when entering this mpx triphone. */
hmm_mpx_ssid(&rhmm->hmm, 0) =
dict2pid_ldiph_lc(d2p, rhmm->ciphone, rhmm->ci2phone, bestbp_rc_ptr->lc);
assert(hmm_mpx_ssid(&rhmm->hmm, 0) != BAD_SSID);
}
}
}
/*
* Single phone words; no right context for these. Cannot use bestbp_rc as
* LM scores have to be included. First find best transition to these words.
*/
for (i = 0; i < ngs->n_1ph_LMwords; i++) {
w = ngs->single_phone_wid[i];
ngs->last_ltrans[w].dscr = (int32) 0x80000000;
}
for (bp = ngs->bp_table_idx[frame_idx]; bp < ngs->bpidx; bp++) {
bpe = &(ngs->bp_table[bp]);
if (!bpe->valid)
continue;
for (i = 0; i < ngs->n_1ph_LMwords; i++) {
int32 n_used;
w = ngs->single_phone_wid[i];
newscore = ngram_search_exit_score
(ngs, bpe, dict_first_phone(dict, w));
E_DEBUG(4, ("initial newscore for %s: %d\n",
dict_wordstr(dict, w), newscore));
if (newscore != WORST_SCORE)
newscore += ngram_tg_score(ngs->lmset,
dict_basewid(dict, w),
bpe->real_wid,
bpe->prev_real_wid,
&n_used)>>SENSCR_SHIFT;
/* FIXME: Not sure how WORST_SCORE could be better, but it
* apparently happens. */
if (newscore BETTER_THAN ngs->last_ltrans[w].dscr) {
ngs->last_ltrans[w].dscr = newscore;
ngs->last_ltrans[w].bp = bp;
}
}
}
/* Now transition to in-LM single phone words */
for (i = 0; i < ngs->n_1ph_LMwords; i++) {
w = ngs->single_phone_wid[i];
/* Never transition into the start word (for one thing, it is
a non-event in the language model.) */
if (w == dict_startwid(ps_search_dict(ngs)))
continue;
rhmm = (root_chan_t *) ngs->word_chan[w];
newscore = ngs->last_ltrans[w].dscr + ngs->pip;
pl_newscore = newscore + phone_loop_search_score(pls, rhmm->ciphone);
if (pl_newscore BETTER_THAN thresh) {
bpe = ngs->bp_table + ngs->last_ltrans[w].bp;
if ((hmm_frame(&rhmm->hmm) < frame_idx)
|| (newscore BETTER_THAN hmm_in_score(&rhmm->hmm))) {
hmm_enter(&rhmm->hmm,
newscore, ngs->last_ltrans[w].bp, nf);
/* DICT2PID: another place where mpx ssids are entered. */
/* Look up the ssid to use when entering this mpx triphone. */
hmm_mpx_ssid(&rhmm->hmm, 0) =
dict2pid_ldiph_lc(d2p, rhmm->ciphone, rhmm->ci2phone,
dict_last_phone(dict, bpe->wid));
assert(hmm_mpx_ssid(&rhmm->hmm, 0) != BAD_SSID);
}
}
}
/* Remaining words: <sil>, noise words. No mpx for these! */
w = ps_search_silence_wid(ngs);
rhmm = (root_chan_t *) ngs->word_chan[w];
bestbp_rc_ptr = &(ngs->bestbp_rc[ps_search_acmod(ngs)->mdef->sil]);
newscore = bestbp_rc_ptr->score + ngs->silpen + ngs->pip;
pl_newscore = newscore
+ phone_loop_search_score(pls, rhmm->ciphone);
if (pl_newscore BETTER_THAN thresh) {
if ((hmm_frame(&rhmm->hmm) < frame_idx)
|| (newscore BETTER_THAN hmm_in_score(&rhmm->hmm))) {
hmm_enter(&rhmm->hmm,
newscore, bestbp_rc_ptr->path, nf);
}
}
for (w = dict_filler_start(dict); w <= dict_filler_end(dict); w++) {
if (w == ps_search_silence_wid(ngs))
continue;
/* Never transition into the start word (for one thing, it is
a non-event in the language model.) */
if (w == dict_startwid(ps_search_dict(ngs)))
continue;
rhmm = (root_chan_t *) ngs->word_chan[w];
/* If this was not actually a single-phone word, rhmm will be NULL. */
if (rhmm == NULL)
continue;
newscore = bestbp_rc_ptr->score + ngs->fillpen + ngs->pip;
pl_newscore = newscore
+ phone_loop_search_score(pls, rhmm->ciphone);
if (pl_newscore BETTER_THAN thresh) {
if ((hmm_frame(&rhmm->hmm) < frame_idx)
|| (newscore BETTER_THAN hmm_in_score(&rhmm->hmm))) {
hmm_enter(&rhmm->hmm,
newscore, bestbp_rc_ptr->path, nf);
}
}
}
}
static void
deactivate_channels(ngram_search_t *ngs, int frame_idx)
{
root_chan_t *rhmm;
int i;
/* Clear score[] of pruned root channels */
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
if (hmm_frame(&rhmm->hmm) == frame_idx) {
hmm_clear(&rhmm->hmm);
}
}
/* Clear score[] of pruned single-phone channels */
for (i = 0; i < ngs->n_1ph_words; i++) {
int32 w = ngs->single_phone_wid[i];
rhmm = (root_chan_t *) ngs->word_chan[w];
if (hmm_frame(&rhmm->hmm) == frame_idx) {
hmm_clear(&rhmm->hmm);
}
}
}
int
ngram_fwdtree_search(ngram_search_t *ngs, int frame_idx)
{
int16 const *senscr;
/* Activate our HMMs for the current frame if need be. */
if (!ps_search_acmod(ngs)->compallsen)
compute_sen_active(ngs, frame_idx);
/* Compute GMM scores for the current frame. */
if ((senscr = acmod_score(ps_search_acmod(ngs), &frame_idx)) == NULL)
return 0;
ngs->st.n_senone_active_utt += ps_search_acmod(ngs)->n_senone_active;
/* Mark backpointer table for current frame. */
ngram_search_mark_bptable(ngs, frame_idx);
/* If the best score is equal to or worse than WORST_SCORE,
* recognition has failed, don't bother to keep trying. */
if (ngs->best_score == WORST_SCORE || ngs->best_score WORSE_THAN WORST_SCORE)
return 0;
/* Renormalize if necessary */
if (ngs->best_score + (2 * ngs->beam) WORSE_THAN WORST_SCORE) {
E_INFO("Renormalizing Scores at frame %d, best score %d\n",
frame_idx, ngs->best_score);
renormalize_scores(ngs, frame_idx, ngs->best_score);
}
/* Evaluate HMMs */
evaluate_channels(ngs, senscr, frame_idx);
/* Prune HMMs and do phone transitions. */
prune_channels(ngs, frame_idx);
/* Do absolute pruning on word exits. */
bptable_maxwpf(ngs, frame_idx);
/* Do word transitions. */
word_transition(ngs, frame_idx);
/* Deactivate pruned HMMs. */
deactivate_channels(ngs, frame_idx);
++ngs->n_frame;
/* Return the number of frames processed. */
return 1;
}
void
ngram_fwdtree_finish(ngram_search_t *ngs)
{
int32 i, w, cf, *awl;
root_chan_t *rhmm;
chan_t *hmm, **acl;
/* This is the number of frames processed. */
cf = ps_search_acmod(ngs)->output_frame;
/* Add a mark in the backpointer table for one past the final frame. */
ngram_search_mark_bptable(ngs, cf);
/* Deactivate channels lined up for the next frame */
/* First, root channels of HMM tree */
for (i = ngs->n_root_chan, rhmm = ngs->root_chan; i > 0; --i, rhmm++) {
hmm_clear(&rhmm->hmm);
}
/* nonroot channels of HMM tree */
i = ngs->n_active_chan[cf & 0x1];
acl = ngs->active_chan_list[cf & 0x1];
for (hmm = *(acl++); i > 0; --i, hmm = *(acl++)) {
hmm_clear(&hmm->hmm);
}
/* word channels */
i = ngs->n_active_word[cf & 0x1];
awl = ngs->active_word_list[cf & 0x1];
for (w = *(awl++); i > 0; --i, w = *(awl++)) {
/* Don't accidentally free single-phone words! */
if (dict_is_single_phone(ps_search_dict(ngs), w))
continue;
bitvec_clear(ngs->word_active, w);
if (ngs->word_chan[w] == NULL)
continue;
ngram_search_free_all_rc(ngs, w);
}
/*
* The previous search code did a postprocessing of the
* backpointer table here, but we will postpone this until it is
* absolutely necessary, i.e. when generating a word graph.
* Likewise we don't actually have to decide what the exit word is
* until somebody requests a backtrace.
*/
ptmr_stop(&ngs->fwdtree_perf);
/* Print out some statistics. */
if (cf > 0) {
double n_speech = (double)(cf + 1)
/ cmd_ln_int32_r(ps_search_config(ngs), "-frate");
E_INFO("%8d words recognized (%d/fr)\n",
ngs->bpidx, (ngs->bpidx + (cf >> 1)) / (cf + 1));
E_INFO("%8d senones evaluated (%d/fr)\n", ngs->st.n_senone_active_utt,
(ngs->st.n_senone_active_utt + (cf >> 1)) / (cf + 1));
E_INFO("%8d channels searched (%d/fr), %d 1st, %d last\n",
ngs->st.n_root_chan_eval + ngs->st.n_nonroot_chan_eval,
(ngs->st.n_root_chan_eval + ngs->st.n_nonroot_chan_eval) / (cf + 1),
ngs->st.n_root_chan_eval, ngs->st.n_last_chan_eval);
E_INFO("%8d words for which last channels evaluated (%d/fr)\n",
ngs->st.n_word_lastchan_eval,
ngs->st.n_word_lastchan_eval / (cf + 1));
E_INFO("%8d candidate words for entering last phone (%d/fr)\n",
ngs->st.n_lastphn_cand_utt, ngs->st.n_lastphn_cand_utt / (cf + 1));
E_INFO("fwdtree %.2f CPU %.3f xRT\n",
ngs->fwdtree_perf.t_cpu,
ngs->fwdtree_perf.t_cpu / n_speech);
E_INFO("fwdtree %.2f wall %.3f xRT\n",
ngs->fwdtree_perf.t_elapsed,
ngs->fwdtree_perf.t_elapsed / n_speech);
}
/* dump_bptable(ngs); */
}
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