src/libpocketsphinx/lts.c

/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/*************************************************************************/
/*                                                                       */
/*                  Language Technologies Institute                      */
/*                     Carnegie Mellon University                        */
/*                        Copyright (c) 1999                             */
/*                        All Rights Reserved.                           */
/*                                                                       */
/*  Permission is hereby granted, free of charge, to use and distribute  */
/*  this software and its documentation without restriction, including   */
/*  without limitation the rights to use, copy, modify, merge, publish,  */
/*  distribute, sublicense, and/or sell copies of this work, and to      */
/*  permit persons to whom this work is furnished to do so, subject to   */
/*  the following conditions:                                            */
/*   1. The code must retain the above copyright notice, this list of    */
/*      conditions and the following disclaimer.                         */
/*   2. Any modifications must be clearly marked as such.                */
/*   3. Original authors' names are not deleted.                         */
/*   4. The authors' names are not used to endorse or promote products   */
/*      derived from this software without specific prior written        */
/*      permission.                                                      */
/*                                                                       */
/*  CARNEGIE MELLON UNIVERSITY AND THE CONTRIBUTORS TO THIS WORK         */
/*  DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING      */
/*  ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT   */
/*  SHALL CARNEGIE MELLON UNIVERSITY NOR THE CONTRIBUTORS BE LIABLE      */
/*  FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES    */
/*  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN   */
/*  AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,          */
/*  ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF       */
/*  THIS SOFTWARE.                                                       */
/*                                                                       */
/*************************************************************************/
/*             Author:  Alan W Black (awb@cs.cmu.edu)                    */
/*               Date:  December 1999                                    */
/*************************************************************************/
/*                                                                       */
/*  Letter to sound rule support                                         */
/*                                                                       */
/*************************************************************************/
/* Modified for SphinxTrain by David Huggins-Daines <dhuggins@cs.cmu.edu> */
/* Modified for sphinx3 by Arthur Chan <archan@cs.cmu.edu>                */

/*
 * lts.c -- Letter to sound rule support 
 * 
 * $Log$
 * Revision 1.3  2006/03/01  21:44:26  egouvea
 * Removed magic number "6", and swap variable if machine is big endian.
 * 
 * Revision 1.2  2006/02/22 20:44:17  arthchan2003
 * Merged from branch SPHINX3_5_2_RCI_IRII_BRANCH: As we have done in SphinxTrain and with the permission of flite developer. check in the routines for using LTS. In dict.c, one will see detail comment on how it was used and how we avoid problematic conditions.
 *
 * Revision 1.1.2.1  2005/09/25 19:07:52  arthchan2003
 * Added LTS rules and the module to use it.
 *
 *
 */

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include "lts.h"
#include "ckd_alloc.h"
#include "bio.h"


static cst_lts_phone apply_model(cst_lts_letter * vals,
                                 cst_lts_addr start,
                                 const cst_lts_model * model);

void
lex_print(lex_entry_t * ent)
{
    int i;

    for (i = 0; i < ent->phone_cnt; ++i) {
        printf("%s ", ent->phone[i]);
    }
    printf("\n");
    fflush(stdout);
}

static char *
cst_substr(const char *str, int start, int length)
{
    char *nstr = NULL;

    if (str) {
        nstr = ckd_malloc(length + 1);
        strncpy(nstr, str + start, length);
        nstr[length] = '\0';
    }
    return nstr;
}

int
lts_apply(const char *in_word, const char *feats,
          const cst_lts_rules * r, lex_entry_t * out_phones)
{
    int pos, index, i, maxphones;
    cst_lts_letter *fval_buff;
    cst_lts_letter *full_buff;
    cst_lts_phone phone;
    char *left, *right, *p;
    char hash;
    char zeros[8];
    char *word;

    /* Downcase the incoming word unless we are a non-roman alphabet. */
    word = ckd_salloc((char *) in_word);
    if (!r->letter_table)
        for (i = 0; i < strlen(word); ++i)
            word[i] = tolower(word[i]);

    /* Fill in out_phones structure as best we can. */
    maxphones = strlen(word) + 10;
    out_phones->phone = ckd_malloc(maxphones * sizeof(char *));
    out_phones->ci_acmod_id = ckd_malloc(maxphones * sizeof(acmod_id_t));
    out_phones->phone_cnt = 0;

    /* For feature vals for each letter */
    fval_buff = ckd_calloc((r->context_window_size * 2) +
                           r->context_extra_feats, sizeof(cst_lts_letter));
    /* Buffer with added contexts */
    full_buff = ckd_calloc((r->context_window_size * 2) +       /* TBD assumes single POS feat */
                           strlen(word) + 1, sizeof(cst_lts_letter));
    if (r->letter_table) {
        for (i = 0; i < 8; i++)
            zeros[i] = 2;
        sprintf((char *)full_buff, "%.*s%c%s%c%.*s",
                r->context_window_size - 1, zeros,
                1, word, 1, r->context_window_size - 1, zeros);
        hash = 1;
    }
    else {
        /* Assumes l_letter is a char and context < 8 */
        sprintf((char *)full_buff, "%.*s#%s#%.*s",
                r->context_window_size - 1, "00000000",
                word, r->context_window_size - 1, "00000000");
        hash = '#';
    }

    /* Do the prediction forwards (begone, foul LISP!) */
    for (pos = r->context_window_size; full_buff[pos] != hash; ++pos) {
        /* Fill the features buffer for the predictor */
        sprintf((char *)fval_buff, "%.*s%.*s%s",
                r->context_window_size,
                full_buff + pos - r->context_window_size,
                r->context_window_size, full_buff + pos + 1, feats);
        if ((!r->letter_table
             && ((full_buff[pos] < 'a') || (full_buff[pos] > 'z')))) {
#ifdef EXCESSIVELY_CHATTY
            E_WARN("lts:skipping unknown char \"%c\"\n", full_buff[pos]);
#endif
            continue;
        }
        if (r->letter_table)
            index = full_buff[pos] - 3;
        else
            index = (full_buff[pos] - 'a') % 26;
        phone = apply_model(fval_buff, r->letter_index[index], r->models);
        /* delete epsilons and split dual-phones */
        if (0 == strcmp("epsilon", r->phone_table[phone]))
            continue;
        /* dynamically grow out_phones if necessary. */
        if (out_phones->phone_cnt + 2 > maxphones) {
            maxphones += 10;
            out_phones->phone = ckd_realloc(out_phones->phone,
                                            maxphones * sizeof(char *));
            out_phones->ci_acmod_id = ckd_realloc(out_phones->ci_acmod_id,
                                                  maxphones *
                                                  sizeof(acmod_id_t));
        }
        if ((p = strchr(r->phone_table[phone], '-')) != NULL) {
            left = cst_substr(r->phone_table[phone], 0,
                              strlen(r->phone_table[phone]) - strlen(p));
            right = cst_substr(r->phone_table[phone],
                               (strlen(r->phone_table[phone]) -
                                strlen(p)) + 1, (strlen(p) - 1));
            out_phones->phone[out_phones->phone_cnt++] = left;
            out_phones->phone[out_phones->phone_cnt++] = right;
        }
        else
            out_phones->phone[out_phones->phone_cnt++] =
                ckd_salloc((char *) r->phone_table[phone]);
    }


    ckd_free(full_buff);
    ckd_free(fval_buff);
    ckd_free(word);
    return S3_SUCCESS;
}

static cst_lts_phone
apply_model(cst_lts_letter * vals, cst_lts_addr start,
            const cst_lts_model * model)
{
    /* because some machines (ipaq/mips) can't deal with addrs not on     */
    /* word boundaries we use a static and copy the rule values each time */
    /* so we know its properly aligned                                    */
    /* Hmm this still might be wrong on some machines that align the      */
    /* structure cst_lts_rules differently                                */
    cst_lts_rule state;
    unsigned short nstate;
    static const int sizeof_cst_lts_rule = sizeof(cst_lts_rule);

    memmove(&state, &model[start * sizeof_cst_lts_rule],
            sizeof_cst_lts_rule);
    for (; state.feat != CST_LTS_EOR;) {
        if (vals[state.feat] == state.val)
            nstate = state.qtrue;
        else
            nstate = state.qfalse;

#if defined(WORDS_BIGENDIAN)
        SWAP_INT16(&nstate);
#endif

        memmove(&state, &model[nstate * sizeof_cst_lts_rule],
                sizeof_cst_lts_rule);
    }

    return (cst_lts_phone) state.val;
}

#ifdef UNIT_TEST
/* gcc -DUNIT_TEST -I../../libutil/ -I../libcommon/ cmu6_lts_rules.c lts.c ../libcommon/bio.c ../../libutil/err.c ../../libutil/ckd_alloc.c*/

int
main(int argc, char *argv[])
{
    lex_entry_t out;
    int i;

    lts_apply("HELLO", "", &cmu6_lts_rules, &out);
    lex_print(&out);
    ckd_free(out.phone);
    ckd_free(out.ci_acmod_id);

    lts_apply("EXCELLENT", "", &cmu6_lts_rules, &out);
    lex_print(&out);
    ckd_free(out.phone);
    ckd_free(out.ci_acmod_id);

    lts_apply("TWELVE", "", &cmu6_lts_rules, &out);
    lex_print(&out);
    ckd_free(out.phone);
    ckd_free(out.ci_acmod_id);

    return 0;
}
#endif

---