Ejemplo n.º 1
0
int32
fsg_model_tag_trans_add(fsg_model_t * fsg, int32 from, int32 to,
                        int32 logp, int32 wid)
{
    fsg_link_t *link, *link2;

    /* Check for transition probability */
    if (logp > 0) {
        E_FATAL("Null transition prob must be <= 1.0 (state %d -> %d)\n",
                from, to);
    }

    /* Self-loop null transitions (with prob <= 1.0) are redundant */
    if (from == to)
        return -1;

    if (fsg->trans[from].null_trans == NULL)
        fsg->trans[from].null_trans = hash_table_new(5, HASH_CASE_YES);

    /* Check for a duplicate link; if found, keep the higher prob */
    link = fsg_model_null_trans(fsg, from, to);
    if (link) {
        if (link->logs2prob < logp) {
            link->logs2prob = logp;
            return 0;
        }
        else
            return -1;
    }

    /* Create null transition object */
    link = listelem_malloc(fsg->link_alloc);
    link->from_state = from;
    link->to_state = to;
    link->logs2prob = logp;
    link->wid = -1;

    link2 = (fsg_link_t *)
        hash_table_enter_bkey(fsg->trans[from].null_trans,
                              (char const *) &link->to_state,
                              sizeof(link->to_state), link);
    assert(link == link2);

    return 1;
}
Ejemplo n.º 2
0
fsg_model_t *
fsg_model_read(FILE * fp, logmath_t * lmath, float32 lw)
{
    fsg_model_t *fsg;
    hash_table_t *vocab;
    hash_iter_t *itor;
    int32 lastwid;
    char **wordptr;
    char *lineptr;
    char *fsgname;
    int32 lineno;
    int32 n, i, j;
    int n_state, n_trans, n_null_trans;
    glist_t nulls;
    float32 p;

    lineno = 0;
    vocab = hash_table_new(32, FALSE);
    wordptr = NULL;
    lineptr = NULL;
    nulls = NULL;
    fsgname = NULL;
    fsg = NULL;

    /* Scan upto FSG_BEGIN header */
    for (;;) {
        n = nextline_str2words(fp, &lineno, &lineptr, &wordptr);
        if (n < 0) {
            E_ERROR("%s declaration missing\n", FSG_MODEL_BEGIN_DECL);
            goto parse_error;
        }

        if ((strcmp(wordptr[0], FSG_MODEL_BEGIN_DECL) == 0)) {
            if (n > 2) {
                E_ERROR("Line[%d]: malformed FSG_BEGIN declaration\n",
                        lineno);
                goto parse_error;
            }
            break;
        }
    }
    /* Save FSG name, or it will get clobbered below :(.
     * If name is missing, try the default.
     */
    if (n == 2) {
        fsgname = ckd_salloc(wordptr[1]);
    }
    else {
        E_WARN("FSG name is missing\n");
        fsgname = ckd_salloc("unknown");
    }

    /* Read #states */
    n = nextline_str2words(fp, &lineno, &lineptr, &wordptr);
    if ((n != 2)
        || ((strcmp(wordptr[0], FSG_MODEL_N_DECL) != 0)
            && (strcmp(wordptr[0], FSG_MODEL_NUM_STATES_DECL) != 0))
        || (sscanf(wordptr[1], "%d", &n_state) != 1)
        || (n_state <= 0)) {
        E_ERROR
            ("Line[%d]: #states declaration line missing or malformed\n",
             lineno);
        goto parse_error;
    }

    /* Now create the FSG. */
    fsg = fsg_model_init(fsgname, lmath, lw, n_state);
    ckd_free(fsgname);
    fsgname = NULL;

    /* Read start state */
    n = nextline_str2words(fp, &lineno, &lineptr, &wordptr);
    if ((n != 2)
        || ((strcmp(wordptr[0], FSG_MODEL_S_DECL) != 0)
            && (strcmp(wordptr[0], FSG_MODEL_START_STATE_DECL) != 0))
        || (sscanf(wordptr[1], "%d", &(fsg->start_state)) != 1)
        || (fsg->start_state < 0)
        || (fsg->start_state >= fsg->n_state)) {
        E_ERROR
            ("Line[%d]: start state declaration line missing or malformed\n",
             lineno);
        goto parse_error;
    }

    /* Read final state */
    n = nextline_str2words(fp, &lineno, &lineptr, &wordptr);
    if ((n != 2)
        || ((strcmp(wordptr[0], FSG_MODEL_F_DECL) != 0)
            && (strcmp(wordptr[0], FSG_MODEL_FINAL_STATE_DECL) != 0))
        || (sscanf(wordptr[1], "%d", &(fsg->final_state)) != 1)
        || (fsg->final_state < 0)
        || (fsg->final_state >= fsg->n_state)) {
        E_ERROR
            ("Line[%d]: final state declaration line missing or malformed\n",
             lineno);
        goto parse_error;
    }

    /* Read transitions */
    lastwid = 0;
    n_trans = n_null_trans = 0;
    for (;;) {
        int32 wid, tprob;

        n = nextline_str2words(fp, &lineno, &lineptr, &wordptr);
        if (n <= 0) {
            E_ERROR("Line[%d]: transition or FSG_END statement expected\n",
                    lineno);
            goto parse_error;
        }

        if ((strcmp(wordptr[0], FSG_MODEL_END_DECL) == 0)) {
            break;
        }

        if ((strcmp(wordptr[0], FSG_MODEL_T_DECL) == 0)
            || (strcmp(wordptr[0], FSG_MODEL_TRANSITION_DECL) == 0)) {


            if (((n != 4) && (n != 5))
                || (sscanf(wordptr[1], "%d", &i) != 1)
                || (sscanf(wordptr[2], "%d", &j) != 1)
                || (i < 0) || (i >= fsg->n_state)
                || (j < 0) || (j >= fsg->n_state)) {
                E_ERROR
                    ("Line[%d]: transition spec malformed; Expecting: from-state to-state trans-prob [word]\n",
                     lineno);
                goto parse_error;
            }

            p = atof_c(wordptr[3]);
            if ((p <= 0.0) || (p > 1.0)) {
                E_ERROR
                    ("Line[%d]: transition spec malformed; Expecting float as transition probability\n",
                     lineno);
                goto parse_error;
            }
        }
        else {
            E_ERROR("Line[%d]: transition or FSG_END statement expected\n",
                    lineno);
            goto parse_error;
        }

        tprob = (int32) (logmath_log(lmath, p) * fsg->lw);
        /* Add word to "dictionary". */
        if (n > 4) {
            if (hash_table_lookup_int32(vocab, wordptr[4], &wid) < 0) {
                (void) hash_table_enter_int32(vocab,
                                              ckd_salloc(wordptr[4]),
                                              lastwid);
                wid = lastwid;
                ++lastwid;
            }
            fsg_model_trans_add(fsg, i, j, tprob, wid);
            ++n_trans;
        }
        else {
            if (fsg_model_null_trans_add(fsg, i, j, tprob) == 1) {
                ++n_null_trans;
                nulls =
                    glist_add_ptr(nulls, fsg_model_null_trans(fsg, i, j));
            }
        }
    }

    E_INFO("FSG: %d states, %d unique words, %d transitions (%d null)\n",
           fsg->n_state, hash_table_inuse(vocab), n_trans, n_null_trans);


    /* Now create a string table from the "dictionary" */
    fsg->n_word = hash_table_inuse(vocab);
    fsg->n_word_alloc = fsg->n_word + 10;       /* Pad it a bit. */
    fsg->vocab = ckd_calloc(fsg->n_word_alloc, sizeof(*fsg->vocab));
    for (itor = hash_table_iter(vocab); itor;
         itor = hash_table_iter_next(itor)) {
        char const *word = hash_entry_key(itor->ent);
        int32 wid = (int32) (long) hash_entry_val(itor->ent);
        fsg->vocab[wid] = (char *) word;
    }
    hash_table_free(vocab);

    /* Do transitive closure on null transitions */
    nulls = fsg_model_null_trans_closure(fsg, nulls);
    glist_free(nulls);

    ckd_free(lineptr);
    ckd_free(wordptr);

    return fsg;

  parse_error:
    for (itor = hash_table_iter(vocab); itor;
         itor = hash_table_iter_next(itor))
        ckd_free((char *) hash_entry_key(itor->ent));
    glist_free(nulls);
    hash_table_free(vocab);
    ckd_free(fsgname);
    ckd_free(lineptr);
    ckd_free(wordptr);
    fsg_model_free(fsg);
    return NULL;
}
Ejemplo n.º 3
0
glist_t
fsg_model_null_trans_closure(fsg_model_t * fsg, glist_t nulls)
{
    gnode_t *gn1;
    int updated;
    fsg_link_t *tl1, *tl2;
    int32 k, n;

    E_INFO("Computing transitive closure for null transitions\n");

    if (nulls == NULL) {
        fsg_link_t *null;
        int i, j;

        for (i = 0; i < fsg->n_state; ++i) {
            for (j = 0; j < fsg->n_state; ++j) {
                if ((null = fsg_model_null_trans(fsg, i, j)))
                    nulls = glist_add_ptr(nulls, null);
            }
        }
    }

    /*
     * Probably not the most efficient closure implementation, in general, but
     * probably reasonably efficient for a sparse null transition matrix.
     */
    n = 0;
    do {
        updated = FALSE;

        for (gn1 = nulls; gn1; gn1 = gnode_next(gn1)) {
            hash_iter_t *itor;

            tl1 = (fsg_link_t *) gnode_ptr(gn1);
            assert(tl1->wid < 0);

            if (fsg->trans[tl1->to_state].null_trans == NULL)
                continue;

            for (itor = hash_table_iter(fsg->trans[tl1->to_state].null_trans);
                 itor; itor = hash_table_iter_next(itor)) {

                tl2 = (fsg_link_t *) hash_entry_val(itor->ent);

                k = fsg_model_null_trans_add(fsg,
                                             tl1->from_state,
                                             tl2->to_state,
                                             tl1->logs2prob +
                                             tl2->logs2prob);
                if (k >= 0) {
                    updated = TRUE;
                    if (k > 0) {
                        nulls = glist_add_ptr(nulls, (void *)
                                              fsg_model_null_trans
                                              (fsg, tl1->from_state,
                                               tl2->to_state));
                        n++;
                    }
                }
            }
        }
    } while (updated);
    
    E_INFO("%d null transitions added\n", n);

    return nulls;
}
Ejemplo n.º 4
0
glist_t
fsg_model_null_trans_closure(fsg_model_t * fsg, glist_t nulls)
{
    gnode_t *gn1;
    int updated;
    fsg_link_t *tl1, *tl2;
    int32 k, n;

    E_INFO("Computing transitive closure for null transitions\n");

    /* If our caller didn't give us a list of null-transitions,
       make such a list. Just loop through all the FSG states, 
       and all the null-transitions in that state (which are kept in
       their own hash table). */
    if (nulls == NULL) {
        int i;
        for (i = 0; i < fsg->n_state; ++i) {
            hash_iter_t *itor;
            hash_table_t *null_trans = fsg->trans[i].null_trans;
            if (null_trans == NULL)
                continue;
            for (itor = hash_table_iter(null_trans);
                 itor != NULL;
                 itor = hash_table_iter_next(itor)) {
                nulls = glist_add_ptr(nulls, hash_entry_val(itor->ent));
            }
        }
    }

    /*
     * Probably not the most efficient closure implementation, in general, but
     * probably reasonably efficient for a sparse null transition matrix.
     */
    n = 0;
    do {
        updated = FALSE;

        for (gn1 = nulls; gn1; gn1 = gnode_next(gn1)) {
            hash_iter_t *itor;

            tl1 = (fsg_link_t *) gnode_ptr(gn1);
            assert(tl1->wid < 0);

            if (fsg->trans[tl1->to_state].null_trans == NULL)
                continue;

            for (itor = hash_table_iter(fsg->trans[tl1->to_state].null_trans);
                 itor; itor = hash_table_iter_next(itor)) {

                tl2 = (fsg_link_t *) hash_entry_val(itor->ent);

                k = fsg_model_null_trans_add(fsg,
                                             tl1->from_state,
                                             tl2->to_state,
                                             tl1->logs2prob +
                                             tl2->logs2prob);
                if (k >= 0) {
                    updated = TRUE;
                    if (k > 0) {
                        nulls = glist_add_ptr(nulls, (void *)
                                              fsg_model_null_trans
                                              (fsg, tl1->from_state,
                                               tl2->to_state));
                        n++;
                    }
                }
            }
        }
    } while (updated);
    
    E_INFO("%d null transitions added\n", n);

    return nulls;
}