src/feat/cmn.h

/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
/* ====================================================================
 * Copyright (c) 1999-2004 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.
 *
 * ====================================================================
 *
 */
/*
 * cmn.h -- Various forms of cepstral mean normalization
 *
 * **********************************************
 * CMU ARPA Speech Project
 *
 * Copyright (c) 1999 Carnegie Mellon University.
 * ALL RIGHTS RESERVED.
 * **********************************************
 * 
 * HISTORY
 * $Log$
 * Revision 1.1  2006/04/05  20:27:30  dhdfu
 * A Great Reorganzation of header files and executables
 * 
 * Revision 1.13  2006/02/23 03:48:27  arthchan2003
 * Resolved conflict in cmn.h
 *
 *
 * Revision 1.12  2006/02/22 23:43:55  arthchan2003
 * Merged from the branch SPHINX3_5_2_RCI_IRII_BRANCH: Put data structure into the cmn_t structure.
 *
 * Revision 1.11.4.2  2005/10/17 04:45:57  arthchan2003
 * Free stuffs in cmn and feat corectly.
 *
 * Revision 1.11.4.1  2005/07/05 06:25:08  arthchan2003
 * Fixed dox-doc.
 *
 * Revision 1.11  2005/06/21 19:28:00  arthchan2003
 * 1, Fixed doxygen documentation. 2, Added $ keyword.
 *
 * Revision 1.4  2005/06/13 04:02:56  archan
 * Fixed most doxygen-style documentation under libs3decoder.
 *
 * Revision 1.3  2005/03/30 01:22:46  archan
 * Fixed mistakes in last updates. Add
 *
 * 
 * 20.Apr.2001  RAH (rhoughton@mediasite.com, ricky.houghton@cs.cmu.edu)
 *              Added cmn_free() and moved *mean and *var out global space and named them cmn_mean and cmn_var
 * 
 * 28-Apr-1999	M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University
 * 		Copied from previous version.
 */


#ifndef _S3_CMN_H_
#define _S3_CMN_H_

#include "fe/fe.h"

#ifdef __cplusplus
extern "C" {
#endif
#if 0
/* Fool Emacs. */
}
#endif

/** \file cmn.h
 * \brief Apply Cepstral Mean Normalization (CMN) to the set of input mfc frames.
 *
 * By subtractingthe mean of the input from each frame.  C0 is also included in this process.
 * This function operates on an entire utterance at a time.  Hence, the entire utterance
 * must be available beforehand (batchmode).
 */

/**
 * Types of cepstral mean normalization to apply to the features.
 */
typedef enum cmn_type_e {
    CMN_NONE = 0,
    CMN_BATCH,
    CMN_LIVE
} cmn_type_t;

/** String representations of cmn_type_t values. */
extern const char *cmn_type_str[];

/** Convert string representation (from command-line) to cmn_type_t */
cmn_type_t cmn_type_from_str(const char *str);

/** \struct cmn_t
 *  \brief wrapper of operation of the cepstral mean normalization. 
 */

typedef struct {
    mfcc_t *cmn_mean;   /**< Current means */
    mfcc_t *cmn_var;    /**< Stored cmn variance */
    mfcc_t *sum;        /**< Accumulated cepstra for computing mean */
    int32 nframe;	/**< Number of frames */
    int32 veclen;	/**< Length of cepstral vector */
    char *repr;         /**< String representation of current means */
    int refcount;
} cmn_t;

cmn_t* cmn_init(int32 veclen);

/**
 * CMN for the whole sentence
*/
void cmn (cmn_t *cmn,   /**< In/Out: cmn normalization, which contains the cmn_mean and cmn_var) */
          mfcc_t **mfc,	/**< In/Out: mfc[f] = mfc vector in frame f */
	  int32 varnorm,/**< In: if not FALSE, variance normalize the input vectors
			   to have unit variance (along each dimension independently);
			   Irrelevant if no cmn is performed */
	  int32 n_frame /**< In: Number of frames of mfc vectors */
	);

#define CMN_WIN_HWM     800     /* #frames after which window shifted */
#define CMN_WIN         500

/**
 * CMN for one block of data, using live mean
 */
void cmn_live(cmn_t *cmn,        /**< In/Out: cmn normalization, which contains
                                    the cmn_mean and cmn_var) */
               mfcc_t **incep,  /**< In/Out: mfc[f] = mfc vector in frame f*/
	       int32 varnorm,    /**< This flag should always be 0 for live */
	       int32 nfr         /**< Number of incoming frames */
    );

/**
 * Update live mean based on observed data
 */
void cmn_live_update(cmn_t *cmn);

/**
 * Set live mean from a vector of length cmn->veclen
 */
void cmn_live_set(cmn_t *cmn, mfcc_t const * vec);

/**
 * Get the string representation of the live mean.
 */
#define cmn_repr(cmn) (cmn)->repr

/**
 * Update the string representation.
 */
const char *cmn_update_repr(cmn_t *cmn);

/**
 * Set the live mean from a string.
 */
int cmn_set_repr(cmn_t *cmn, char const *repr);

/**
 * Retain a CMN.
 */
cmn_t *cmn_retain(cmn_t *cmn);

/**
 * Release a CMN, possibly freeing it.
 */
int cmn_free (cmn_t *cmn);

#ifdef __cplusplus
}
#endif

#endif