ms_senone.h

CMU大名鼎鼎的SPHINX－3大词汇量连续语音识别系统

/*
 * senone.h -- Mixture density weights associated with each tied state.
 *
 * **********************************************
 * CMU ARPA Speech Project
 *
 * Copyright (c) 1996 Carnegie Mellon University.
 * ALL RIGHTS RESERVED.
 * **********************************************
 * 
 * HISTORY
 * 
 * $Log: ms_senone.h,v $
 * Revision 1.4  2004/12/06 10:52:01  arthchan2003
 * Enable doxygen documentation in libs3decoder
 *
 * Revision 1.3  2004/11/13 21:25:19  arthchan2003
 * commit of 1, absolute CI-GMMS , 2, fast CI senone computation using svq, 3, Decrease the number of static variables, 4, fixing the random generator problem of vector_vqgen, 5, move all unused files to NOTUSED
 *
 * Revision 1.2  2004/08/31 08:43:47  arthchan2003
 * Fixing _cpluscplus directive
 *
 * Revision 1.1  2004/08/09 00:17:11  arthchan2003
 * Incorporating s3.0 align, at this point, there are still some small problems in align but they don't hurt. For example, the score doesn't match with s3.0 and the output will have problem if files are piped to /dev/null/. I think we can go for it.
 *
 * Revision 1.1  2003/02/14 14:40:34  cbq
 * Compiles.  Analysis is probably hosed.
 *
 * Revision 1.1  2000/04/24 09:39:41  lenzo
 * s3 import.
 *
 * 
 * 13-Dec-95	M K Ravishankar ([e-mail]) at Carnegie Mellon University.
 * 		Added senone_eval_all().
 * 
 * 12-Nov-95	M K Ravishankar ([e-mail]) at Carnegie Mellon University.
 * 		Created.
 */


#ifndef _LIBFBS_SENONE_H_
#define _LIBFBS_SENONE_H_


#include "s3types.h"
#include "ms_gauden.h"

/** \file ms_senone.h
 *  \brief (Sphinx 3.0 specific) multiple streams senones. used with ms_gauden.h
 */

#ifdef __cplusplus
extern "C" {
#endif

typedef uint8 senprob_t;	/** Senone logs3-probs, truncated to 8 bits */

  /**
 * 8-bit senone PDF structure.  Senone pdf values are normalized, floored, converted to
 * logs3 domain, and finally truncated to 8 bits precision to conserve memory space.
 */
typedef struct {
    senprob_t ***pdf;		/** gaussian density mixture weights, organized two possible
				   ways depending on n_gauden:
				   if (n_gauden > 1): pdf[sen][feat][codeword].  Not an
				       efficient representation--memory access-wise--but
				       evaluating the many codebooks will be more costly.
				   if (n_gauden == 1): pdf[feat][codeword][sen].  Optimized
				       for the shared-distribution semi-continuous case. */
    int32 n_sen;		/** #senones in this set */
    int32 n_feat;		/** #feature streams */ 
    int32 n_cw;			/** #codewords per codebook,stream */
    int32 n_gauden;		/** #gaussian density codebooks referred to by senones */
    float32 mixwfloor;		/** floor applied to each PDF entry */
    int32 shift;		/** LSB bits truncated from original logs3 value */
    s3mgauid_t *mgau;		/** senone-id -> mgau-id mapping for senones in this set */
    int32* featscr;              /** The feature score for every senone, will be initialized inside senone_eval_all */
} senone_t;


  /**
 * Load a set of senones (mixing weights and mixture gaussian codebook mappings) from
 * the given files.  Normalize weights for each codebook, apply the given floor, convert
 * PDF values to logs3 domain and quantize to 8-bits.
 * Return value: pointer to senone structure created.  Caller MUST NOT change its contents.
 */
senone_t *senone_init (char *mixwfile,		/** In: mixing weights file */
		       char *mgau_mapfile,	/** In: file specifying mapping from each
						   senone to mixture gaussian codebook.
						   If NULL all senones map to codebook 0 */
		       float32 mixwfloor);	/** In: Floor value for senone weights */

  /**
 * Evaluate the score for the given senone wrt to the given top N gaussian codewords.
 * Return value: senone score (in logs3 domain).
 */
int32 senone_eval (senone_t *s, s3senid_t id,	/** In: senone for which score desired */
		   gauden_dist_t **dist,	/** In: top N codewords and densities for
						   all features, to be combined into
						   senone score.  IE, dist[f][i] = i-th
						   best <codeword,density> for feaure f */
		   int32 n_top);		/** In: Length of dist[f], for each f */

  /**
 * Like senone_eval, but compute all senone scores for the shared density case (ie,
 * #codebooks = 1).
 */
void senone_eval_all (senone_t *s,		/** In: Senone structure */
		      gauden_dist_t **dist,	/** In: as in senone_eval above */
		      int32 n_top,		/** In: as in senone_eval above */
		      int32 *senscr);		/** Out: Upon return, senscr[i] will contain
						   score for senone i */

#ifdef __cplusplus
}
#endif

#endif