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
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
|
/*
* Revision 1.2 1996/08/20 20:30:11 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Removed init function, since all initialization is now done in
* init_lpc10_encoder_state().
*
* Changed name of function from lpcenc_ to lpc10_encode, simply to make
* all lpc10 functions have more consistent naming with each other.
*
* Revision 1.1 1996/08/19 22:31:48 jaf
* Initial revision
*
*/
/* -- translated by f2c (version 19951025).
You must link the resulting object file with the libraries:
-lf2c -lm (in that order)
*/
#include "f2c.h"
extern int lpcdec_(integer *bits, real *speech);
extern int initlpcdec_(void);
/* Common Block Declarations */
extern struct {
integer order, lframe;
logical corrp;
} contrl_;
#define contrl_1 contrl_
/* Table of constant values */
static integer c__10 = 10;
/* ***************************************************************** */
/*
* Revision 1.2 1996/08/20 20:30:11 jaf
* Removed all static local variables that were SAVE'd in the Fortran
* code, and put them in struct lpc10_encoder_state that is passed as an
* argument.
*
* Removed init function, since all initialization is now done in
* init_lpc10_encoder_state().
*
* Changed name of function from lpcenc_ to lpc10_encode, simply to make
* all lpc10 functions have more consistent naming with each other.
*
* Revision 1.1 1996/08/19 22:31:48 jaf
* Initial revision
* */
/* Revision 1.1 1996/03/28 00:03:00 jaf */
/* Initial revision */
/* ***************************************************************** */
/* Decode 54 bits to one frame of 180 speech samples. */
/* Input: */
/* BITS - 54 encoded bits, stored 1 per array element. */
/* Indices 1 through 53 read (SYNC bit ignored). */
/* Output: */
/* SPEECH - Speech encoded as real values in the range [-1,+1]. */
/* Indices 1 through 180 written. */
/* This subroutine maintains local state from one call to the next. If */
/* you want to switch to using a new audio stream for this filter, or */
/* reinitialize its state for any other reason, call the ENTRY */
/* INITLPCDEC. */
/* Subroutine */ int lpc10_decode(integer *bits, real *speech,
struct lpc10_decoder_state *st)
{
integer irms, voice[2], pitch, ipitv;
extern /* Subroutine */ int decode_(integer *, integer *, integer *,
integer *, integer *, real *, real *, struct lpc10_decoder_state *);
real rc[10];
extern /* Subroutine */ int chanrd_(integer *, integer *, integer *,
integer *, integer *), synths_(integer *,
integer *, real *, real *, real *, integer *,
struct lpc10_decoder_state *);
integer irc[10], len;
real rms;
/* LPC Configuration parameters: */
/* Frame size, Prediction order, Pitch period */
/* Arguments */
/* LPC Processing control variables: */
/* *** Read-only: initialized in setup */
/* Files for Speech, Parameter, and Bitstream Input & Output, */
/* and message and debug outputs. */
/* Here are the only files which use these variables: */
/* lpcsim.f setup.f trans.f error.f vqsetup.f */
/* Many files which use fdebug are not listed, since it is only used in */
/* those other files conditionally, to print trace statements. */
/* integer fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
/* LPC order, Frame size, Quantization rate, Bits per frame, */
/* Error correction */
/* Subroutine SETUP is the only place where order is assigned a value, */
/* and that value is 10. It could increase efficiency 1% or so to */
/* declare order as a constant (i.e., a Fortran PARAMETER) instead of as
*/
/* a variable in a COMMON block, since it is used in many places in the */
/* core of the coding and decoding routines. Actually, I take that back.
*/
/* At least when compiling with f2c, the upper bound of DO loops is */
/* stored in a local variable before the DO loop begins, and then that is
*/
/* compared against on each iteration. */
/* Similarly for lframe, which is given a value of MAXFRM in SETUP. */
/* Similarly for quant, which is given a value of 2400 in SETUP. quant */
/* is used in only a few places, and never in the core coding and */
/* decoding routines, so it could be eliminated entirely. */
/* nbits is similar to quant, and is given a value of 54 in SETUP. */
/* corrp is given a value of .TRUE. in SETUP, and is only used in the */
/* subroutines ENCODE and DECODE. It doesn't affect the speed of the */
/* coder significantly whether it is .TRUE. or .FALSE., or whether it is
*/
/* a constant or a variable, since it is only examined once per frame. */
/* Leaving it as a variable that is set to .TRUE. seems like a good */
/* idea, since it does enable some error-correction capability for */
/* unvoiced frames, with no change in the coding rate, and no noticeable
*/
/* quality difference in the decoded speech. */
/* integer quant, nbits */
/* *** Read/write: variables for debugging, not needed for LPC algorithm
*/
/* Current frame, Unstable frames, Output clip count, Max onset buffer,
*/
/* Debug listing detail level, Line count on listing page */
/* nframe is not needed for an embedded LPC10 at all. */
/* nunsfm is initialized to 0 in SETUP, and incremented in subroutine */
/* ERROR, which is only called from RCCHK. When LPC10 is embedded into */
/* an application, I would recommend removing the call to ERROR in RCCHK,
*/
/* and remove ERROR and nunsfm completely. */
/* iclip is initialized to 0 in SETUP, and incremented in entry SWRITE in
*/
/* sread.f. When LPC10 is embedded into an application, one might want */
/* to cause it to be incremented in a routine that takes the output of */
/* SYNTHS and sends it to an audio device. It could be optionally */
/* displayed, for those that might want to know what it is. */
/* maxosp is never initialized to 0 in SETUP, although it probably should
*/
/* be, and it is updated in subroutine ANALYS. I doubt that its value */
/* would be of much interest to an application in which LPC10 is */
/* embedded. */
/* listl and lincnt are not needed for an embedded LPC10 at all. */
/* integer nframe, nunsfm, iclip, maxosp, listl, lincnt */
/* common /contrl/ fsi, fso, fpi, fpo, fbi, fbo, pbin, fmsg, fdebug */
/* common /contrl/ quant, nbits */
/* common /contrl/ nframe, nunsfm, iclip, maxosp, listl, lincnt */
/* Local variables that need not be saved */
/* Uncoded speech parameters */
/* Coded speech parameters */
/* Others */
/* Local state */
/* None */
/* Parameter adjustments */
if (bits) {
--bits;
}
if (speech) {
--speech;
}
/* Function Body */
chanrd_(&c__10, &ipitv, &irms, irc, &bits[1]);
decode_(&ipitv, &irms, irc, voice, &pitch, &rms, rc, st);
synths_(voice, &pitch, &rms, rc, &speech[1], &len, st);
return 0;
} /* lpcdec_ */
|
