/* ====================================================================
 * Copyright (c) 1995-2000 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: acmod_set.c
 * 
 * Description: 
 *	This is an implementation of the acmod_set (acoustic model set) module.
 *	It's primary function is to create and maintain the
 *	one-to-one mapping from ASCII acoustic model names to consecutive
 *	integers from 0 through N-1 where N is the total number
 *	of acoustic models known by the system.
 *
 *	Another function is to create/maintain an attribute list
 *	associated w/ each acoustic model and be able to answer attribute
 *	existence questions above a given acoustic model (e.g. Is this acoustic model
 *	a filler model?, etc.).
 *
 * ------------------------------------------------------------------
 *	RESTRICTIONS OF THIS IMPLEMENTATION:
 *
 *	- All base acoustic models must be defined before any triphone.
 *	- No more than 256 CI acoustic models may be defined
 *	- Triphones are the only multiphones supported at present.
 * ------------------------------------------------------------------
 *
 *	A workable calling sequence to this interface is be:
 *
 *		p = acmod_set_new()		- creates a new acmod_set structure
 *		acmod_set_set_n_ci_hint(p, ...)	- gives an optional CI acoustic model
 *					  	  count
 *		acmod_set_set_n_tri_hint(p, ...)- gives an optional triphone model
 *					  	  count.
 * 		for (...) {			
 *			acmod_set_add_ci(p, ...); - add in all the ci
 *							phones
 *		}
 *		for (...) {
 *			acmod_set_add_tri(p, ...);  - add in all the tri phones
 *		}
 *
 *		base = acmod_set_name2id(p, base_name);   - map a base phone name to an
 *					     		    id.
 *		left = acmod_set_name2id(p, left_ctxt_name);
 *					
 *		right = acmod_set_name2id(p, right_ctxt_name);
 *
 *		tri = acmod_set_tri2id(p, base, right, posn);   - get a triphone id
 *							     given base, left, right
 *							     and word position.
 *
 * Author: 
 * 	Eric H. Thayer (eht@cs)
 *********************************************************************/


#include <s3/acmod_set.h>

#include <sphinxbase/ckd_alloc.h>
#include <s3/s2_param.h>
#include <s3/s3.h>

#include <stdio.h>
#include <string.h>
#include <assert.h>

/*********************************************************************
 *
 * Function: acmod_set_new()
 * 
 * Description: 
 *	This function will create a new acmod_set structure.
 *	It allocates space for the object and zeros the
 *	allocated space so that all the counts contained in it are
 *	zero initially and all the pointers are NULL.
 * 
 * Function Inputs: 
 *	None
 * 
 * Global Inputs: 
 *	None
 * 
 * Return Values: 
 *	A pointer to an allocated acmod_set_t structure.
 * 
 * Global Outputs: 
 *	None
 * 
 * Postconditions:
 *	Return value must be a pointer to allocated space for a
 *	acmod_set_t structure.
 *
 * Errors: 
 *	None at this level.
 * 
 *********************************************************************/

acmod_set_t *
acmod_set_new()
{
    /* ckd_calloc() will exit if the allocation fails */

    return ckd_calloc(1, sizeof(acmod_set_t));
}

/*********************************************************************
 *
 * Function: acmod_set_set_n_ci_hint()
 * 
 * Description: 
 *	For those callers that know in advance how many CI phones
 *	will be created in the acoustic model set, this routine
 *	gives a chance to pre-allocate space for them.
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 *	None
 * 
 * Return Values: 
 *	S3_SUCCESS - if call completed successfully.
 * 
 * Global Outputs: 
 *	None
 * 
 * Pre-Conditions: 
 *	acmod_set argument must be a valid non-zero pointer.
 *
 * Errors: 
 *	None at this level (subroutines might abort)
 * 
 *********************************************************************/

int32
acmod_set_set_n_ci_hint(acmod_set_t *acmod_set,
			uint32 n_ci)
{
    assert(acmod_set->ci == NULL);

    /* ckd_calloc aborts if no mem is avail */
    acmod_set->ci = ckd_calloc(n_ci,
			       sizeof(ci_acmod_t));

    acmod_set->max_n_ci = n_ci;

    assert(acmod_set->next_id == 0);

    return S3_SUCCESS;
}

int32
acmod_set_set_n_tri_hint(acmod_set_t *acmod_set,
			 uint32 n_tri)
{
    assert(acmod_set->multi == NULL);
    assert(acmod_set->max_n_multi == 0);
    assert(acmod_set->n_multi == 0);
    
    if (n_tri > 0) {
	acmod_set->multi = ckd_calloc(n_tri,
				      sizeof(acmod_t));

	acmod_set->max_n_multi = n_tri;
    }

    return S3_SUCCESS;
}

const char **new_attrib(const char **in)
{
    char **out;
    uint32 len, i;

    for (len = 0; in[len]; len++);

    out = (char **)ckd_calloc(len+1, sizeof(char *));

    for (i = 0; i < len; i++) {
	out[i] = strdup(in[i]);
    }

    out[i] = NULL;

    return (const char **)out;
}

/*********************************************************************
 *
 * Function: acmod_set_add_ci()
 * 
 * Description: 
 * 	This routine will add a context independent acoustic model to
 *	the set.
 *
 * Function Inputs: 
 * 
 * Global Inputs: 
 *	None
 * 
 * Return Values: 
 * 	The id of the new CI model
 *
 * Global Outputs: 
 *	None
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 *	- No prior calls to acmod_set_add_tri() have been made.
 *
 * Errors: 
 * 
 *********************************************************************/

acmod_id_t
acmod_set_add_ci(acmod_set_t *acmod_set,
		 const char *name,
		 const char **attrib)
{
    uint32 id;

    if (acmod_set->n_multi > 0) {
	E_FATAL("Current acmod_set implementation requires all CI phones"
		"to be defined before defining multi phones\n");
    }

    if (acmod_set->n_ci == acmod_set->max_n_ci) {
	E_FATAL("Current acmod_set implementation requires the 'n_ci_hint' to be"
		"exactly the number to be added.\n");
    }

    id = acmod_set->next_id;

    acmod_set->next_id++;
    acmod_set->n_ci++;

    /* copy the name and attribute lists so that the caller
     * does not have restrictions on overwriting the value
     * of the passed arguments */

    acmod_set->ci[id].name   = strdup(name);
    acmod_set->ci[id].attrib = new_attrib(attrib);

    /* the following allows ci_acmod_t structures to be
       passed w/o reference to the acmod_set structure itself */
    acmod_set->ci[id].id = id;

    return id;
}

/*********************************************************************
 *
 * Function: acmod_set_add_tri()
 * 
 * Description: 
 *	This function adds a new triphone to the phone set.
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 * 	None
 * 
 * Return Values: 
 *	An ID for the new triphone.
 * 
 * Global Outputs: 
 * 	None
 * 
 * Errors: 
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 * 
 *********************************************************************/

acmod_id_t
acmod_set_add_tri(acmod_set_t *acmod_set,
		  acmod_id_t base,
		  acmod_id_t left_context,
		  acmod_id_t right_context,
		  word_posn_t posn,
		  const char **attrib)
{
    acmod_id_t new;
    uint32 addr;
    uint32 n_ci;
    uint32 i;
    acmod_t *multi;

    if (acmod_set->n_multi == acmod_set->max_n_multi) {
	E_FATAL("Current acmod_set implementation requires the 'n_tri_hint' to "
		"be not less than the number to be added.\n");
    }
    
    /* get the multi-phone list (e.g. di, tri, quad phones ) */
    multi = acmod_set->multi;

    n_ci = acmod_set->n_ci;

    if (acmod_set->multi_idx == NULL) {
	/* allocate space for multiphone -> acoustic model id
	 * index */

	acmod_set->multi_idx = ckd_calloc(n_ci,
					  sizeof(itree_t *));

	  /* HACK! In theory, n_ci * n_ci * N_WORD_POSN should be
	     enough to store all possible triphones.  However, in
	     practice, we have seen situation where, the number of
	     cells allocated in itree is bigger than n_ci * n_ci *
	     N_WORD_POSN.  This simply mean there might be something
	     wrong within the itree module.

	     One could follow this thread of discussion to further the
	     investigation at
	     http://sourceforge.net/forum/forum.php?thread_id=1541914&forum_id=5471
	     
	     The resource is checked in and could be found in test
	     bugcase1. This will solve the immediate the problem which
	     the user was suffering.  We should revisit this issue
	     later on.
	   */

	for (i = 0; i < n_ci; i++) {	  
	  acmod_set->multi_idx[i] = itree_new(n_ci * n_ci * N_WORD_POSN * 2); 
	  /*  acmod_set->multi_idx[i] = itree_new(n_ci * n_ci * N_WORD_POSN ); */
	}
    }
    
    assert(base < 256);
    assert(left_context < 256);
    assert(right_context < 256);

    new = acmod_set->next_id;

    /* adds an index cell for this triphone. */
    itree_add_tri(acmod_set->multi_idx[base],
		  left_context, right_context, posn,
		  new);
    
    /* multiphone list does not include CI acoustic models */
    addr = new - n_ci;
    
    /* get ready for next add if any */
    acmod_set->next_id++;

    multi[addr].base = base;
    multi[addr].left_context = left_context;
    multi[addr].right_context = right_context;
    multi[addr].posn = posn;
    multi[addr].attrib = new_attrib(attrib);

    acmod_set->n_multi++;

    return new;
}

/*********************************************************************
 *
 * Function: acmod_set_name2id()
 * 
 * Description: 
 *	This function maps the C string name for a phone into
 *	a phone id.
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 * 	None
 * 
 * Return Values: 
 *	The ID for the phone - if it exists
 *	NO_ACMOD	     - otherwise.
 * 
 * Global Outputs: 
 * 	None
 * 
 * Errors: 
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 * 
 *********************************************************************/

acmod_id_t
acmod_set_name2id(acmod_set_t *acmod_set,
		  const char *name)
{
    uint32 i;
    char tmp_store[1024];
    char *tmp;
    int n_scan;
    int n_assign;
    char base[1024];
    acmod_id_t base_id;

    char left[1024];
    acmod_id_t left_id;

    char right[1024];
    acmod_id_t right_id;

    char *word_posn_map = WORD_POSN_CHAR_MAP;
    char posn[12];
    uint32 posn_id;

    strcpy(tmp_store, name);

    tmp = tmp_store;

    n_assign = sscanf(tmp, "%s%n", base, &n_scan);
    tmp += n_scan;

    if (n_assign != 1) {
	E_ERROR("Error parsing acoustic model name %s\n", name);
	return NO_ACMOD;
    }

    n_assign = sscanf(tmp, "%s%n", left, &n_scan);
    tmp += n_scan;
    
    if (n_assign != 1) {
	for (i = 0; i < acmod_set->n_ci; i++) {
	    if (strcmp(acmod_set->ci[i].name, base) == 0)
		return i;
	}
    
	return NO_ACMOD;
    }
    else {
	n_assign = sscanf(tmp, "%s%n", right, &n_scan);
	tmp += n_scan;
    
	if (n_assign != 1) {
	    E_ERROR("Parse error while getting right context of %s\n", name);

	    return NO_ACMOD;
	}

	n_assign = sscanf(tmp, "%s%n", posn, &n_scan);
	tmp += n_scan;
    
	if (n_assign != 1) {
	    E_ERROR("Parse error while getting word position of %s\n", name);
	    
	    return NO_ACMOD;
	}

	base_id  = acmod_set_name2id(acmod_set, base);
	left_id  = acmod_set_name2id(acmod_set, left);
	right_id = acmod_set_name2id(acmod_set, right);

	for (posn_id = 0; posn_id < strlen(word_posn_map); posn_id++) {
	    if (posn[0] == word_posn_map[(uint32)posn_id])
		break;
	}

	if (posn_id == strlen(word_posn_map)) {
	    E_ERROR("Unknown word position identifier %s\n", posn);

	    return NO_ACMOD;
	}
	
	return acmod_set_tri2id(acmod_set, base_id, left_id, right_id, (word_posn_t)posn_id);
    }
    
    return NO_ACMOD;
}

/*********************************************************************
 *
 * Function: acmod_set_id2s2name()
 * 
 * Description: 
 *	This function maps a phone ID into a SPHINX-II phone name
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 * 	None
 * 
 * Return Values: 
 *	A C string name for the phone	- if the ID is valid
 *	NULL				- otherwise.
 * 
 * Global Outputs: 
 * 	None
 * 
 * Errors: 
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 *********************************************************************/

const char *
acmod_set_id2s2name(acmod_set_t *acmod_set,
		    acmod_id_t id)
{
    static char str[1024];
    char *pmap = WORD_POSN_CHAR_MAP;
    acmod_id_t base;
    acmod_id_t left;
    acmod_id_t right;
    word_posn_t posn;
    
    if (id < acmod_set->n_ci)
	return acmod_set->ci[id].name;
    
    else if (id < acmod_set->next_id) {

	acmod_set_id2tri(acmod_set, &base, &left, &right, &posn, id);

	sprintf(str, "%s(%s,%s)%c",
		acmod_set_id2name(acmod_set, base),
		acmod_set_id2name(acmod_set, left),
		acmod_set_id2name(acmod_set, right),
		(posn != WORD_POSN_INTERNAL ? pmap[(int)posn] : '\0'));
	
	return str;
    }
    else
	return NULL;
}

/*********************************************************************
 *
 * Function: acmod_set_id2name()
 * 
 * Description: 
 *	This function maps a phone ID into a C string.
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 * 	None
 * 
 * Return Values: 
 *	A C string name for the phone	- if the ID is valid
 *	NULL				- otherwise.
 * 
 * Global Outputs: 
 * 	None
 * 
 * Errors: 
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 *********************************************************************/

const char *
acmod_set_id2name(acmod_set_t *acmod_set,
		  acmod_id_t id)
{
    static char str[1024];
    char *pmap = WORD_POSN_CHAR_MAP;
    acmod_id_t base;
    acmod_id_t left;
    acmod_id_t right;
    word_posn_t posn;

    if (id < acmod_set->n_ci)
	return acmod_set->ci[id].name;

    else if (id < acmod_set->next_id) {

	acmod_set_id2tri(acmod_set, &base, &left, &right, &posn, id);

	sprintf(str, "%s %s %s %c",
		acmod_set_id2name(acmod_set, base),
		acmod_set_id2name(acmod_set, left),
		acmod_set_id2name(acmod_set, right),
		pmap[(int)posn]);
	
	return str;
    }
    else
	return NULL;
}

/*********************************************************************
 *
 * Function: acmod_set_id2fullname()
 * 
 * Description: 
 *	This function maps a phone ID into a C string where context
 *	independent phones are fully expanded as in mdef files.
 * 
 * Function Inputs: 
 * 
 * Global Inputs: 
 * 	None
 * 
 * Return Values: 
 *	A C string name for the phone	- if the ID is valid
 *	NULL				- otherwise.
 * 
 * Global Outputs: 
 * 	None
 * 
 * Errors: 
 * 
 * Pre-Conditions: 
 *	- acmod_set argument must be a valid non-zero pointer.
 *********************************************************************/

const char *
acmod_set_id2fullname(acmod_set_t *acmod_set,
		      acmod_id_t id)
{
    static char str[1024];
    char *pmap = WORD_POSN_CHAR_MAP;
    acmod_id_t base;
    acmod_id_t left;
    acmod_id_t right;
    word_posn_t posn;

    if (id < acmod_set->n_ci) {
	sprintf(str, "%s - - -", acmod_set->ci[id].name);

	return str;
    }
    else if (id < acmod_set->next_id) {

	acmod_set_id2tri(acmod_set, &base, &left, &right, &posn, id);

	sprintf(str, "%s %s %s %c",
		acmod_set_id2name(acmod_set, base),
		acmod_set_id2name(acmod_set, left),
		acmod_set_id2name(acmod_set, right),
		pmap[(int)posn]);
	
	return str;
    }
    else
	return NULL;
}

acmod_id_t
acmod_set_enum_init(acmod_set_t *acmod_set,
		    acmod_id_t base)
{
    cell_index_t ret;

    if (acmod_set->n_multi == 0) {
	/* none defined */

	return NO_ACMOD;
    }

    ret = itree_enum_init(acmod_set->multi_idx[base]);

    if (ret != NULL_INDEX) {
	return ret;
    }
    else {
	return NO_ACMOD;
    }
}

acmod_id_t
acmod_set_enum()
{
    cell_index_t ret;

    ret = itree_enum();

    if (ret != NULL_INDEX) {
	return ret;
    }
    else {
	return NO_ACMOD;
    }
}

acmod_id_t
acmod_set_tri2id(acmod_set_t *acmod_set,
		 acmod_id_t phone,
		 acmod_id_t left_context,
		 acmod_id_t right_context,
		 word_posn_t posn)
{
    itree_t *idx;
    cell_index_t i;

    if (acmod_set->n_multi == 0) {
	/* none defined */

	return NO_ACMOD;
    }

    idx = acmod_set->multi_idx[phone];

    i = itree_find_tri(idx, left_context, right_context, posn);

    if (i != NULL_INDEX)
	return i;
    else
	return NO_ACMOD;
}

int32
acmod_set_id2tri(acmod_set_t *acmod_set,
		 acmod_id_t *phone,
		 acmod_id_t *left_context,
		 acmod_id_t *right_context,
		 word_posn_t *posn,
		 acmod_id_t id)
{
    acmod_t *multi = acmod_set->multi;
    uint32 addr;

    if (id < acmod_set->n_ci) {
	E_ERROR("ID given to acmod_set_id2tri() is a CI acoustic model ID\n");

	return S3_ERROR;
    }

    addr = id - acmod_set->n_ci;

    *phone         = multi[addr].base;
    *left_context  = multi[addr].left_context;
    *right_context = multi[addr].right_context;
    *posn          = multi[addr].posn;

    assert(acmod_set_tri2id(acmod_set,
			    multi[addr].base,
			    multi[addr].left_context,
			    multi[addr].right_context,
			    multi[addr].posn) == id);
			    
    return S3_SUCCESS;
}

uint32
acmod_set_n_acmod(acmod_set_t *acmod_set)
{
    return acmod_set->n_ci + acmod_set->n_multi;
}

uint32
acmod_set_n_ci(acmod_set_t *acmod_set)
{
    return acmod_set->n_ci;
}

uint32
acmod_set_n_multi(acmod_set_t *acmod_set)
{
    return acmod_set->n_multi;
}

acmod_id_t
acmod_set_base_phone(acmod_set_t *acmod_set, acmod_id_t id)
{
    uint32 addr;

    if (id < acmod_set->n_ci)
	return id;
    else if (id < acmod_set->next_id) {
	addr = id - acmod_set->n_ci;

	return acmod_set->multi[addr].base;
    }
    else {
	E_ERROR("acmod_set_base_phone() ID==%u is out-of-range\n", id);
	
	return NO_ACMOD;
    }
}

int
acmod_set_is_triphone(acmod_set_t *acmod_set, acmod_id_t id)

{
    return id >= acmod_set->n_ci;
}

uint32
acmod_set_has_attrib(acmod_set_t *acmod_set,
		     acmod_id_t id,
		     const char *attrib)
{
    const char **attrib_list;
    uint32 addr;
    uint32 i;

    if (attrib == NULL)
	return FALSE;

    if (id < acmod_set->n_ci) {
	attrib_list = acmod_set->ci[id].attrib;
    }
    else if (id < acmod_set->next_id) {
	addr = id - acmod_set->n_ci;

	attrib_list = acmod_set->multi[addr].attrib;
    }
    else {
	E_ERROR("Phone id %u is out of range.\n", id);

	return FALSE;
    }

    assert(attrib_list);

    for (i = 0; attrib_list[i]; i++) {
	if (strcmp(attrib_list[i], attrib) == 0)
	    return TRUE;
    }

    return FALSE;
}

const char **
acmod_set_attrib(acmod_set_t *acmod_set,
		 acmod_id_t id)
{
    const char **attrib_list;
    uint32 addr;

    if (id < acmod_set->n_ci) {
	attrib_list = acmod_set->ci[id].attrib;
    }
    else if (id < acmod_set->next_id) {
	addr = id - acmod_set->n_ci;

	attrib_list = acmod_set->multi[addr].attrib;
    }
    else {
	E_ERROR("Phone id %u is out of range.\n", id);

	return FALSE;
    }

    assert(attrib_list);
    
    return attrib_list;
}

int
acmod_set_s2_parse_triphone(acmod_set_t *acmod_set,
			    acmod_id_t *base,
			    acmod_id_t *left,
			    acmod_id_t *right,
			    word_posn_t *posn,
			    char *str)
{
    char *tok;
    char *save;
    uint32 i;
    char *pmap = WORD_POSN_CHAR_MAP;

    save = strdup(str);

    tok = strtok(save, "(,)");
    *base = acmod_set_name2id(acmod_set, tok);
    if (*base == NO_ACMOD)
	goto error;

    tok = strtok(NULL, "(,)");
    *left = acmod_set_name2id(acmod_set, tok);
    if (*left == NO_ACMOD)
	goto error;

    tok = strtok(NULL, "(,)");
    *right = acmod_set_name2id(acmod_set, tok);
    if (*right == NO_ACMOD)
	goto error;

    tok = strtok(NULL, "(,)");
    if (tok) {
	for (i = 0; i < strlen(pmap); i++) {
	    if (tok[0] == pmap[i])
		break;
	}

	if (i < strlen(pmap))
	    *posn = (word_posn_t)i;

	/* hack for parsing seno mapping files */
	if (tok[0] == '<')
	    *posn = WORD_POSN_INTERNAL;
    }
    else {
	*posn = WORD_POSN_INTERNAL;
    }
    
    free(save);
    return S3_SUCCESS;

error:
    free(save);
    return S3_ERROR;
}

/*
 * Log record.  Maintained by RCS.
 *
 * $Log$
 * Revision 1.5  2006/02/16  00:18:23  egouvea
 * Implemented flexible warping function. The user can specify at run
 * time which of several shapes they want to use. Currently implemented
 * are an affine function (y = ax + b), an inverse linear (y = a/x) and a
 * piecewise linear (y = ax, up to a frequency F, and then it "breaks" so
 * Nyquist frequency matches in both scales.
 * 
 * Added two switches, -warp_type and -warp_params. The first specifies
 * the type, which valid values:
 * 
 * -inverse or inverse_linear
 * -linear or affine
 * -piecewise or piecewise_linear
 * 
 * The inverse_linear is the same as implemented by EHT. The -mel_warp
 * switch was kept for compatibility (maybe remove it in the
 * future?). The code is compatible with EHT's changes: cepstra created
 * from code after his changes should be the same as now. Scripts that
 * worked with his changes should work now without changes. Tested a few
 * cases, same results.
 * 
 * Revision 1.4  2004/07/21 18:05:39  egouvea
 * Changed the license terms to make it the same as sphinx2 and sphinx3.
 *
 * Revision 1.3  2001/04/05 20:02:30  awb
 * *** empty log message ***
 *
 * Revision 1.2  2000/09/29 22:35:13  awb
 * *** empty log message ***
 *
 * Revision 1.1  2000/09/24 21:38:31  awb
 * *** empty log message ***
 *
 * Revision 1.11  97/07/16  11:36:22  eht
 * *** empty log message ***
 * 
 * Revision 1.10  96/03/25  15:29:13  eht
 * Added id2s2name functions so that SPHINX-II triphone
 * names could be outputted if necessary.
 * 
 * Revision 1.9  1996/03/04  15:53:36  eht
 * Added ability to walk the triphone trees
 *
 * Revision 1.8  1995/10/12  15:07:03  eht
 * Fixed bug when acmod_set_name2id() is given a triphone
 * but the acoustic model set does not have any triphones.
 *
 * Revision 1.7  1995/10/10  15:09:38  eht
 * Cleaned up some signed/unsigned stuff.
 *
 * Revision 1.6  1995/10/09  20:56:36  eht
 * Changes needed for prim_type.h
 *
 * Revision 1.5  1995/10/09  15:02:03  eht
 * Changed ckd_alloc interface to get rid of __FILE__, __LINE__ arguments
 *
 * Revision 1.4  1995/10/05  12:56:42  eht
 * Fix problem w/ attribute lists on HPUX.
 * Make acmod_set interface consistent w/ header file.
 * Extend acmod_set_name2id() to include triphone names.
 *
 * Revision 1.3  1995/09/13  12:27:09  eht
 * Do some sanity checking of the indexing structures.
 *
 * Revision 1.2  1995/09/08  19:11:14  eht
 * Updated to use new acmod_set module.  Prior to testing
 * on TI digits.
 *
 * Revision 1.1  1995/09/08  13:49:52  eht
 * Initial revision
 *
 * Revision 1.1  95/06/02  14:52:54  14:52:54  eht (Eric Thayer)
 * Initial revision
 * 
 *
 */
