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Diffstat (limited to 'media/sphinxbase/src/libsphinxbase/feat/agc.c')
| -rw-r--r-- | media/sphinxbase/src/libsphinxbase/feat/agc.c | 227 |
1 files changed, 0 insertions, 227 deletions
diff --git a/media/sphinxbase/src/libsphinxbase/feat/agc.c b/media/sphinxbase/src/libsphinxbase/feat/agc.c deleted file mode 100644 index 271baf49d..000000000 --- a/media/sphinxbase/src/libsphinxbase/feat/agc.c +++ /dev/null @@ -1,227 +0,0 @@ -/* -*- 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. - * - * ==================================================================== - * - */ -/* - * agc.c -- Various forms of automatic gain control (AGC) - * - * ********************************************** - * CMU ARPA Speech Project - * - * Copyright (c) 1996 Carnegie Mellon University. - * ALL RIGHTS RESERVED. - * ********************************************** - * - * HISTORY - * $Log$ - * Revision 1.5 2005/06/21 19:25:41 arthchan2003 - * 1, Fixed doxygen documentation. 2, Added $ keyword. - * - * Revision 1.3 2005/03/30 01:22:46 archan - * Fixed mistakes in last updates. Add - * - * - * 04-Nov-95 M K Ravishankar (rkm@cs.cmu.edu) at Carnegie Mellon University - * Created. - */ - -#include <string.h> -#ifdef HAVE_CONFIG_H -#include <config.h> -#endif - -#include "sphinxbase/err.h" -#include "sphinxbase/ckd_alloc.h" -#include "sphinxbase/agc.h" - -/* NOTE! These must match the enum in agc.h */ -const char *agc_type_str[] = { - "none", - "max", - "emax", - "noise" -}; -static const int n_agc_type_str = sizeof(agc_type_str)/sizeof(agc_type_str[0]); - -agc_type_t -agc_type_from_str(const char *str) -{ - int i; - - for (i = 0; i < n_agc_type_str; ++i) { - if (0 == strcmp(str, agc_type_str[i])) - return (agc_type_t)i; - } - E_FATAL("Unknown AGC type '%s'\n", str); - return AGC_NONE; -} - -agc_t *agc_init(void) -{ - agc_t *agc; - agc = ckd_calloc(1, sizeof(*agc)); - agc->noise_thresh = FLOAT2MFCC(2.0); - - return agc; -} - -void agc_free(agc_t *agc) -{ - ckd_free(agc); -} - -/** - * Normalize c0 for all frames such that max(c0) = 0. - */ -void -agc_max(agc_t *agc, mfcc_t **mfc, int32 n_frame) -{ - int32 i; - - if (n_frame <= 0) - return; - agc->obs_max = mfc[0][0]; - for (i = 1; i < n_frame; i++) { - if (mfc[i][0] > agc->obs_max) { - agc->obs_max = mfc[i][0]; - agc->obs_frame = 1; - } - } - - E_INFO("AGCMax: obs=max= %.2f\n", agc->obs_max); - for (i = 0; i < n_frame; i++) - mfc[i][0] -= agc->obs_max; -} - -void -agc_emax_set(agc_t *agc, float32 m) -{ - agc->max = FLOAT2MFCC(m); - E_INFO("AGCEMax: max= %.2f\n", m); -} - -float32 -agc_emax_get(agc_t *agc) -{ - return MFCC2FLOAT(agc->max); -} - -void -agc_emax(agc_t *agc, mfcc_t **mfc, int32 n_frame) -{ - int i; - - if (n_frame <= 0) - return; - for (i = 0; i < n_frame; ++i) { - if (mfc[i][0] > agc->obs_max) { - agc->obs_max = mfc[i][0]; - agc->obs_frame = 1; - } - mfc[i][0] -= agc->max; - } -} - -/* Update estimated max for next utterance */ -void -agc_emax_update(agc_t *agc) -{ - if (agc->obs_frame) { /* Update only if some data observed */ - agc->obs_max_sum += agc->obs_max; - agc->obs_utt++; - - /* Re-estimate max over past history; decay the history */ - agc->max = agc->obs_max_sum / agc->obs_utt; - if (agc->obs_utt == 16) { - agc->obs_max_sum /= 2; - agc->obs_utt = 8; - } - } - E_INFO("AGCEMax: obs= %.2f, new= %.2f\n", agc->obs_max, agc->max); - - /* Reset the accumulators for the next utterance. */ - agc->obs_frame = 0; - agc->obs_max = FLOAT2MFCC(-1000.0); /* Less than any real C0 value (hopefully!!) */ -} - -void -agc_noise(agc_t *agc, - mfcc_t **cep, - int32 nfr) -{ - mfcc_t min_energy; /* Minimum log-energy */ - mfcc_t noise_level; /* Average noise_level */ - int32 i; /* frame index */ - int32 noise_frames; /* Number of noise frames */ - - /* Determine minimum log-energy in utterance */ - min_energy = cep[0][0]; - for (i = 0; i < nfr; ++i) { - if (cep[i][0] < min_energy) - min_energy = cep[i][0]; - } - - /* Average all frames between min_energy and min_energy + agc->noise_thresh */ - noise_frames = 0; - noise_level = 0; - min_energy += agc->noise_thresh; - for (i = 0; i < nfr; ++i) { - if (cep[i][0] < min_energy) { - noise_level += cep[i][0]; - noise_frames++; - } - } - - if (noise_frames > 0) { - noise_level /= noise_frames; - E_INFO("AGC NOISE: max= %6.3f\n", MFCC2FLOAT(noise_level)); - /* Subtract noise_level from all log_energy values */ - for (i = 0; i < nfr; i++) { - cep[i][0] -= noise_level; - } - } -} - -void -agc_set_threshold(agc_t *agc, float32 threshold) -{ - agc->noise_thresh = FLOAT2MFCC(threshold); -} - -float32 -agc_get_threshold(agc_t *agc) -{ - return FLOAT2MFCC(agc->noise_thresh); -} |