cmn_prior.h

CMU大名鼎鼎的SPHINX－3大词汇量连续语音识别系统

/* ====================================================================
 * 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
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 * ====================================================================
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/*
 * cmn.h -- Various forms of cepstral mean normalization
 *
 * **********************************************
 * CMU ARPA Speech Project
 *
 * Copyright (c) 1999 Carnegie Mellon University.
 * ALL RIGHTS RESERVED.
 * **********************************************
 * 
 * HISTORY
 * 
 * 28-Apr-1999	M K Ravishankar ([e-mail]) at Carnegie Mellon University
 * 		Copied from previous version.
 */


#ifndef _S3_CMN_PRIOR_H_
#define _S3_CMN_PRIOR_H_

#include <s3types.h>

#ifdef __cplusplus
extern "C" {
#endif

  /** \file cmn_prior.h
   * \brief Block version of implementation of CMN
   * Apply Cepstral Mean Normalization (CMN) to the set of input mfc frames, 
   * by subtracting the mean of the input from each frame.  C0 is also included    * in this process.
   */

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

  /*
   * Simple version of block version of CMN. 
   */
void cmn_prior(float32 **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 */
              int32 ceplen,     /** Length of the cepstral vector */
	      int32 endutt);    /** Flag indicating end of utterance */

#ifdef __cplusplus
}
#endif

#endif