1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
|
/*!
* \file
* \brief Implementation of linear prediction functions, and conversion
* between common representations of linear predictive parameters
* \author Thomas Eriksson
*
* -------------------------------------------------------------------------
*
* IT++ - C++ library of mathematical, signal processing, speech processing,
* and communications classes and functions
*
* Copyright (C) 1995-2008 (see AUTHORS file for a list of contributors)
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* -------------------------------------------------------------------------
* Here we define functions for linear predictive analysis and
* coding. Several functions for computation of lpc parameters are
* given, together with functions to convert between various common
* representations of the lpc polynomial coefficients. The
* functionality is the same as in the MATLAB functions with the same
* names.
*
* The short term for the various parameter types are:
* poly - LPC polynomial coefficients
* ac - autocorrelation coefficients
* rc - reflection coefficients
* lar - log area ratios
* is - inverse sine parameters
* lsf - line spectral frequencies
*/
#ifndef LPCFUNC_H
#define LPCFUNC_H
#include <itpp/base/vec.h>
namespace itpp {
/*! \addtogroup lpc
*/
//!@{
//! Returns a chirped version of the input vector
vec chirp(const vec &a, double factor);
//! Spectral distortion between two vectors, in dB.
double sd(const vec &In1, const vec &In2);
//! Spectral distortion between two vectors, in dB, up to highest frequency highestfreq.
double sd(const vec &In1, const vec &In2, double highestfreq);
//! Computes reflection coefficients from autocorrelation, using the Le-Roux-Guegen algorithm.
vec lerouxguegenrc(const vec &R, int order);
//! Levinson - Levinson-Durbin recursion.
vec levinson(const vec &R2, int order);
//! Computes the autocorrelation function
vec autocorr(const vec &x, int order);
//! lpc - Linear Predictive Coefficients using autocorrelation method.
vec lpc(const vec &x, int order);
//! schurrc - Schur algorithm.
vec schurrc(const vec &R, int order);
//! ac2rc - Autocorrelation sequence to reflection coefficients conversion.
vec ac2rc(const vec &ac);
//! ac2poly - Autocorrelation sequence to prediction polynomial conversion.
vec ac2poly(const vec &ac);
//! is2rc - Inverse sine parameters to reflection coefficients conversion.
vec is2rc(const vec &is);
//! lar2rc - Log area ratios to reflection coefficients conversion.
vec lar2rc(const vec &lar);
//! lsf2poly - Line spectral frequencies to prediction polynomial conversion.
vec lsf2poly(const vec &lsf);
//! poly2ac - Prediction polynomial to autocorrelation sequence conversion.
vec poly2ac(const vec &poly);
//! poly2lsf - Prediction polynomial to line spectral frequencies conversion.
vec poly2lsf(const vec &poly);
//! poly2rc - Prediction polynomial to reflection coefficients conversion.
vec poly2rc(const vec &poly);
//! poly2cepstrum - Prediction polynomial to cepstrum conversion.
vec poly2cepstrum(const vec &a);
//! poly2cepstrum - Prediction polynomial to cepstrum conversion, to the specified order.
vec poly2cepstrum(const vec &a, int num);
//! cepstrum2poly - Cepstrum to prediction polynomial conversion.
vec cepstrum2poly(const vec &c);
//! rc2ac - Reflection coefficients to autocorrelation sequence conversion.
vec rc2ac(const vec &rc);
//! rc2is - Reflection coefficients to inverse sine parameters conversion.
vec rc2is(const vec &rc);
//! rc2lar - Reflection coefficients to log area ratios conversion.
vec rc2lar(const vec &rc);
//! rc2poly - Reflection coefficients to prediction polynomial conversion.
vec rc2poly(const vec &rc);
//!@}
} // namespace itpp
#endif // #ifndef LPCFUNC_H
|
