pocketsphinx / src /feat /cmn_live.c
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/* -*- 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
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* 1. Redistributions of source code must retain the above copyright
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* 2. Redistributions in binary form must reproduce the above copyright
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* 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
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#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef _MSC_VER
#pragma warning (disable: 4244)
#endif
#include <pocketsphinx.h>
#include "util/ckd_alloc.h"
#include "feat/cmn.h"
void
cmn_live_set(cmn_t *cmn, mfcc_t const * vec)
{
int32 i;
E_INFO("Update from < %s >\n", cmn->repr);
for (i = 0; i < cmn->veclen; i++) {
cmn->cmn_mean[i] = vec[i];
cmn->sum[i] = vec[i] * CMN_WIN;
}
cmn->nframe = CMN_WIN;
E_INFO("Update to < %s >\n", cmn_update_repr(cmn));
}
static void
cmn_live_shiftwin(cmn_t *cmn)
{
mfcc_t sf;
int32 i;
E_INFO("Update from < %s >\n", cmn->repr);
sf = FLOAT2MFCC(1.0) / cmn->nframe;
for (i = 0; i < cmn->veclen; i++)
cmn->cmn_mean[i] = cmn->sum[i] / cmn->nframe; /* sum[i] * sf */
/* Make the accumulation decay exponentially */
if (cmn->nframe >= CMN_WIN_HWM) {
sf = CMN_WIN * sf;
for (i = 0; i < cmn->veclen; i++)
cmn->sum[i] = MFCCMUL(cmn->sum[i], sf);
cmn->nframe = CMN_WIN;
}
E_INFO("Update to < %s >\n", cmn_update_repr(cmn));
}
void
cmn_live_update(cmn_t *cmn)
{
mfcc_t sf;
int32 i;
if (cmn->nframe <= 0)
return;
E_INFO("Update from < %s >\n", cmn->repr);
/* Update mean buffer */
sf = FLOAT2MFCC(1.0) / cmn->nframe;
for (i = 0; i < cmn->veclen; i++)
cmn->cmn_mean[i] = cmn->sum[i] / cmn->nframe; /* sum[i] * sf; */
/* Make the accumulation decay exponentially */
if (cmn->nframe > CMN_WIN_HWM) {
sf = CMN_WIN * sf;
for (i = 0; i < cmn->veclen; i++)
cmn->sum[i] = MFCCMUL(cmn->sum[i], sf);
cmn->nframe = CMN_WIN;
}
E_INFO("Update to < %s >\n", cmn_update_repr(cmn));
}
void
cmn_live(cmn_t *cmn, mfcc_t **incep, int32 varnorm, int32 nfr)
{
int32 i, j;
if (nfr <= 0)
return;
if (varnorm)
E_FATAL
("Variance normalization not implemented in live mode decode\n");
for (i = 0; i < nfr; i++) {
/* Skip zero energy frames */
if (incep[i][0] < 0)
continue;
for (j = 0; j < cmn->veclen; j++) {
cmn->sum[j] += incep[i][j];
incep[i][j] -= cmn->cmn_mean[j];
}
++cmn->nframe;
}
/* Shift buffer down if we have more than CMN_WIN_HWM frames */
if (cmn->nframe > CMN_WIN_HWM)
cmn_live_shiftwin(cmn);
}