cmn.c

/* -*- c-basic-offset: 4; indent-tabs-mode: nil -*- */
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 * Copyright (c) 1999-2004 Carnegie Mellon University.  All rights
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 * 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.
 *
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/*
 * cmn.c -- Various forms of cepstral mean normalization
 *
 * **********************************************
 * CMU ARPA Speech Project
 *
 * Copyright (c) 1996 Carnegie Mellon University.
 * ALL RIGHTS RESERVED.
 * **********************************************
 * 
 * HISTORY
 * $Log$
 * Revision 1.14  2006/02/24  15:57:47  egouvea
 * Removed cmn = NULL from the cmn_free(), since it's pointless (my bad!).
 * 
 * Removed cmn_prior, which was surrounded by #if 0/#endif, since the
 * function is already in cmn_prior.c
 * 
 * Revision 1.13  2006/02/23 03:47:49  arthchan2003
 * Used Evandro's changes. Resolved conflicts.
 *
 *
 * Revision 1.12  2006/02/23 00:48:23  egouvea
 * Replaced loops resetting vectors with the more efficient memset()
 *
 * Revision 1.11  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 1.10.4.2  2005/10/17 04:45:57  arthchan2003
 * Free stuffs in cmn and feat corectly.
 *
 * Revision 1.10.4.1  2005/07/05 06:25:08  arthchan2003
 * Fixed dox-doc.
 *
 * Revision 1.10  2005/06/21 19:28:00  arthchan2003
 * 1, Fixed doxygen documentation. 2, Added $ keyword.
 *
 * 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
 *              Changed the name norm_mean() to cmn().
 * 
 * 19-Jun-1996  M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University
 *              Changed to compute CMN over ALL dimensions of cep instead of 1..12.
 * 
 * 04-Nov-1995  M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University
 *              Created.
 */


#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <math.h>
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#ifdef _MSC_VER
#pragma warning (disable: 4244)
#endif

#include "sphinxbase/ckd_alloc.h"
#include "sphinxbase/err.h"
#include "sphinxbase/cmn.h"

/* NOTE!  These must match the enum in cmn.h */
const char *cmn_type_str[] = {
    "none",
    "current",
    "prior"
};
static const int n_cmn_type_str = sizeof(cmn_type_str)/sizeof(cmn_type_str[0]);

cmn_type_t
cmn_type_from_str(const char *str)
{
    int i;

    for (i = 0; i < n_cmn_type_str; ++i) {
        if (0 == strcmp(str, cmn_type_str[i]))
            return (cmn_type_t)i;
    }
    E_FATAL("Unknown CMN type '%s'\n", str);
    return CMN_NONE;
}

cmn_t *
cmn_init(int32 veclen)
{
    cmn_t *cmn;
    cmn = (cmn_t *) ckd_calloc(1, sizeof(cmn_t));
    cmn->veclen = veclen;
    cmn->cmn_mean = (mfcc_t *) ckd_calloc(veclen, sizeof(mfcc_t));
    cmn->cmn_var = (mfcc_t *) ckd_calloc(veclen, sizeof(mfcc_t));
    cmn->sum = (mfcc_t *) ckd_calloc(veclen, sizeof(mfcc_t));
    /* A front-end dependent magic number */
    cmn->cmn_mean[0] = FLOAT2MFCC(12.0);
    cmn->nframe = 0;
    E_INFO("mean[0]= %.2f, mean[1..%d]= 0.0\n",
           MFCC2FLOAT(cmn->cmn_mean[0]), veclen - 1);

    return cmn;
}


void
cmn(cmn_t *cmn, mfcc_t ** mfc, int32 varnorm, int32 n_frame)
{
    mfcc_t *mfcp;
    mfcc_t t;
    int32 i, f;
    int32 n_pos_frame;

    assert(mfc != NULL);

    if (n_frame <= 0)
        return;

    /* If cmn->cmn_mean wasn't NULL, we need to zero the contents */
    memset(cmn->cmn_mean, 0, cmn->veclen * sizeof(mfcc_t));

    /* Find mean cep vector for this utterance */
    for (f = 0, n_pos_frame = 0; f < n_frame; f++) {
        mfcp = mfc[f];

        /* Skip zero energy frames */
        if (mfcp[0] < 0)
            continue;

        for (i = 0; i < cmn->veclen; i++) {
            cmn->cmn_mean[i] += mfcp[i];
        }

        n_pos_frame++;
    }

    for (i = 0; i < cmn->veclen; i++)
        cmn->cmn_mean[i] /= n_pos_frame;

    E_INFO("CMN: ");
    for (i = 0; i < cmn->veclen; i++)
        E_INFOCONT("%5.2f ", MFCC2FLOAT(cmn->cmn_mean[i]));
    E_INFOCONT("\n");
    if (!varnorm) {
        /* Subtract mean from each cep vector */
        for (f = 0; f < n_frame; f++) {
            mfcp = mfc[f];
            for (i = 0; i < cmn->veclen; i++)
                mfcp[i] -= cmn->cmn_mean[i];
        }
    }
    else {
        /* Scale cep vectors to have unit variance along each dimension, and subtract means */
        /* If cmn->cmn_var wasn't NULL, we need to zero the contents */
        memset(cmn->cmn_var, 0, cmn->veclen * sizeof(mfcc_t));

        for (f = 0; f < n_frame; f++) {
            mfcp = mfc[f];

            for (i = 0; i < cmn->veclen; i++) {
                t = mfcp[i] - cmn->cmn_mean[i];
                cmn->cmn_var[i] += MFCCMUL(t, t);
            }
        }
        for (i = 0; i < cmn->veclen; i++)
            /* Inverse Std. Dev, RAH added type case from sqrt */
            cmn->cmn_var[i] = FLOAT2MFCC(sqrt((float64)n_frame / MFCC2FLOAT(cmn->cmn_var[i])));

        for (f = 0; f < n_frame; f++) {
            mfcp = mfc[f];
            for (i = 0; i < cmn->veclen; i++)
                mfcp[i] = MFCCMUL((mfcp[i] - cmn->cmn_mean[i]), cmn->cmn_var[i]);
        }
    }
}

/* 
 * RAH, free previously allocated memory
 */
void
cmn_free(cmn_t * cmn)
{
    if (cmn != NULL) {
        if (cmn->cmn_var)
            ckd_free((void *) cmn->cmn_var);

        if (cmn->cmn_mean)
            ckd_free((void *) cmn->cmn_mean);

        if (cmn->sum)
            ckd_free((void *) cmn->sum);

        ckd_free((void *) cmn);
    }
}