SphinxBase  0.6
fe_warp.h
1 /* ====================================================================
2  * Copyright (c) 2006 Carnegie Mellon University. All rights
3  * reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  * notice, this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright
13  * notice, this list of conditions and the following disclaimer in
14  * the documentation and/or other materials provided with the
15  * distribution.
16  *
17  * This work was supported in part by funding from the Defense Advanced
18  * Research Projects Agency and the National Science Foundation of the
19  * United States of America, and the CMU Sphinx Speech Consortium.
20  *
21  * THIS SOFTWARE IS PROVIDED BY CARNEGIE MELLON UNIVERSITY ``AS IS'' AND
22  * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
23  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
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36 
37 #ifndef FE_WARP_H
38 #define FE_WARP_H
39 
40 #include "fe_internal.h"
41 
42 #ifdef __cplusplus
43 extern "C" {
44 #endif
45 #if 0
46 /* Fool Emacs. */
47 }
48 #endif
49 
50 #define FE_WARP_ID_INVERSE_LINEAR 0
51 #define FE_WARP_ID_AFFINE 1
52 #define FE_WARP_ID_PIECEWISE_LINEAR 2
53 #define FE_WARP_ID_EIDE_GISH 3
54 #define FE_WARP_ID_MAX 2
55 #define FE_WARP_ID_NONE 0xffffffff
56 
57 typedef struct {
58  void (*set_parameters)(char const *param_str, float sampling_rate);
59  const char * (*doc)(void);
60  uint32 (*id)(void);
61  uint32 (*n_param)(void);
62  float (*warped_to_unwarped)(float nonlinear);
63  float (*unwarped_to_warped)(float linear);
64  void (*print)(const char *label);
66 
67 int fe_warp_set(melfb_t *mel, const char *id_name);
68 
69 uint32 fe_warp_id(melfb_t *mel);
70 
71 const char * fe_warp_doc(melfb_t *mel);
72 
73 void fe_warp_set_parameters(melfb_t *mel, char const *param_str, float sampling_rate);
74 
75 uint32 fe_warp_n_param(melfb_t *mel);
76 
77 float fe_warp_warped_to_unwarped(melfb_t *mel, float nonlinear);
78 
79 float fe_warp_unwarped_to_warped(melfb_t *mel, float linear);
80 
81 void fe_warp_print(melfb_t *mel, const char *label);
82 
83 #define FE_WARP_NO_SIZE 0xffffffff
84 
85 #ifdef __cplusplus
86 }
87 #endif
88 
89 
90 #endif /* FE_WARP_H */
91 
92 /*
93  * Log record. Maintained by RCS.
94  *
95  * $Log: fe_warp.h,v $
96  * Revision 1.2 2006/02/17 00:31:34 egouvea
97  * Removed switch -melwarp. Changed the default for window length to
98  * 0.025625 from 0.256 (so that a window at 16kHz sampling rate has
99  * exactly 410 samples). Cleaned up include's. Replaced some E_FATAL()
100  * with E_WARN() and return.
101  *
102  * Revision 1.1 2006/02/16 00:18:26 egouvea
103  * Implemented flexible warping function. The user can specify at run
104  * time which of several shapes they want to use. Currently implemented
105  * are an affine function (y = ax + b), an inverse linear (y = a/x) and a
106  * piecewise linear (y = ax, up to a frequency F, and then it "breaks" so
107  * Nyquist frequency matches in both scales.
108  *
109  * Added two switches, -warp_type and -warp_params. The first specifies
110  * the type, which valid values:
111  *
112  * -inverse or inverse_linear
113  * -linear or affine
114  * -piecewise or piecewise_linear
115  *
116  * The inverse_linear is the same as implemented by EHT. The -mel_warp
117  * switch was kept for compatibility (maybe remove it in the
118  * future?). The code is compatible with EHT's changes: cepstra created
119  * from code after his changes should be the same as now. Scripts that
120  * worked with his changes should work now without changes. Tested a few
121  * cases, same results.
122  *
123  */
Base Struct to hold all structure for MFCC computation.
Definition: fe_internal.h:89