Mercurial > hg > audiostuff

comparison intercom/gsm/rpeltp.c @ 2:13be24d74cd2

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
import intercom-0.4.1
author Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date Fri, 25 Jun 2010 09:57:52 +0200
parents
children
comparison
equal deleted inserted replaced
1:9cadc470e3da 2:13be24d74cd2
1 /* v1.0 - 12/Apr/1994
2 =============================================================================
3
4 U U GGG SSSS TTTTT
5 U U G S T
6 U U G GG SSSS T
7 U U G G S T
8 UUU GG SSS T
9
10 ========================================
11 ITU-T - USER'S GROUP ON SOFTWARE TOOLS
12 ========================================
13
14 MODULE: RPELTP.C - GSM 06.10 RPE-LTP SPEECH ENCODING ALGORITHM
15
16 ORIGINAL BY:
17
18 The driving routines of this module were written by:
19 Simao Ferraz de Campos Neto
20 DDS/Pr11 Tel: +55-192-39-6637
21 CPqD/Telebras Fax: +55-192-39-6125
22 13088-061 Campinas SP Brazil E-mail: <simao@cpqd.ansp.br>
23
24 The true implementation was done by
25 Jutta Deneger (jutta@cs.tu-berlin.de)
26 Carsten Borman (cabo@cs.tu-berlin.de)
27 Communications and Operating Systems Research Group (KBS)
28 Technishe Universitaet Berlin
29
30 The portability changes on the code and rearrangement were done by <simao>
31
32 DATE: 12/Apr/1994: 18H00 -3H00GMT
33
34 RELEASE: 1.00
35
36 PROTOTYPES: see rpeltp.h for driving-routine prototypes, gsm.h for
37 general prototypes, and private.h for special definitions.
38
39 OBSERVATION:
40 Copyright note by the original authors:
41 " Copyright 1992 by Jutta Degener and Carsten Bormann, Technische
42 Universitaet Berlin. See the accompanying file "COPYRIGHT" for
43 details. THERE IS ABSOLUTELY NO WARRANTY FOR THIS SOFTWARE."
44
45 FUNCTIONS: (Only UGST user-level functions!)
46
47 rpeltp_init() ......... Initializes the state variable for the encoding or
48 the decoding algorithm. Each need a separate state
49 variable!!!
50
51 rpeltp_delete ......... Delete the state variable allocation, etc (an alias).
52
53 rpeltp_encode ......... Entry-level function for the encoding algorithm.
54
55 rpeltp_decode ......... Entry-level function for the decoding algorithm.
56
57 ============================================================================
58 */
59 #include <stdio.h> /* For NULL */
60 #include "private.h"
61 #include "gsm.h"
62 #include "rpeltp.h"
63
64 /* *** Alias functions *** */
65 /*
66 ------------------------------------------------------------------------
67 void rpeltp_delete(gsm_state *st);
68 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
69
70 Description:
71 ~~~~~~~~~~~~
72 Frees memory of a state variable previously initialized by a call to
73 rpeltp_init(). This is an alias to the function gsm_destroy() implemented
74 by the original authors of the module.
75
76 Variables:
77 ~~~~~~~~~~
78 A pointer to a valid encoder or decoder state variable.
79
80 Return value:
81 ~~~~~~~~~~~~~
82 None.
83
84 Prototype: in gsm.h
85 ~~~~~~~~~~
86
87 Original author:
88 ~~~~~~~~~~~~~~~~
89 Simao Ferraz de Campos Neto
90 DDS/Pr11 Tel: +55-192-39-6637
91 CPqD/Telebras Fax: +55-192-39-6125
92 13088-061 Campinas SP Brazil E-mail: <simao@cpqd.ansp.br>
93
94 Log of changes:
95 ~~~~~~~~~~~~~~~
96 12.Apr.94 v.1.0 created.
97
98 ------------------------------------------------------------------------
99 */
100 /* #define rpeltp_delete gsm_destroy / * This is already done in rpeltp.h !!! */
101 /* ................... End of rpeltp_delete() ......................... */
102
103
104 /* *** True functions *** */
105
106 /*
107 ------------------------------------------------------------------------
108 gsm_state *rpeltp_init(void);
109 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
110
111 Description:
112 ~~~~~~~~~~~~
113 Allocates memory for the state variable of the encoder or the decoder,
114 and resets flags to proper initial values. This includes processing
115 strictly according to the Rec. GSM 06.10.
116
117 In a encoder plus decoder calling program there must exist different
118 state variables for the encoder and for the decoder.
119
120 Variables:
121 ~~~~~~~~~~
122 None.
123
124 Return value:
125 ~~~~~~~~~~~~~
126 Returns a pointer to a valid encoder or decoder state variable. On
127 failure, returns NULL.
128
129 Prototype: in rpeltp.h
130 ~~~~~~~~~~
131
132 Original author:
133 ~~~~~~~~~~~~~~~~
134 Simao Ferraz de Campos Neto
135 DDS/Pr11 Tel: +55-192-39-6637
136 CPqD/Telebras Fax: +55-192-39-6125
137 13088-061 Campinas SP Brazil E-mail: <simao@cpqd.ansp.br>
138
139 Log of changes:
140 ~~~~~~~~~~~~~~~
141 12.Apr.94 v.1.0 created.
142
143 ------------------------------------------------------------------------
144 */
145 gsm rpeltp_init()
146 {
147 gsm rpe_state;
148 int gsm_compliant = 0;
149
150 /* Initializa state variable */
151 if (!(rpe_state = gsm_create()))
152 return ((gsm) (NULL));
153
154 /* The gsm_{en,de}code() routines may operate on a compliant mode, or
155 * in a non-compliant, faster mode - here we use the complyant one */
156 (void) gsm_option(rpe_state, GSM_OPT_FAST, &gsm_compliant);
157
158 return (rpe_state);
159 }
160
161 /* ................... End of rpeltp_init() ......................... */
162
163
164 /*
165 ------------------------------------------------------------------------
166 void gsm_state *rpeltp_encode (gsm_state *rpe_state, short *inp_buf,
167 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ short *rpe_frame);
168
169
170 Description:
171 ~~~~~~~~~~~~
172 Process the input buffer inp_buf with left-aligned 16-bit linear-format,
173 2-complement samples using 13-bit resolution, i.e., the lower 3 bits of
174 each input sample are ignored.
175
176 The rpe-ltp frame buffer rpe_frame is word-oriented (16-bit samples),
177 right-aligned i.e., the lower bits are the most significatives.
178 They follow the sequence specified by the `parameter number' in
179 Table 1.1 of the Rec.GSM-06.10.
180
181 The input buffer has always 160 samples, and the generated frame has
182 always 76 samples.
183
184 Variables:
185 ~~~~~~~~~~
186 rpe_state ... state variable initialized by a previous call to rpeltp_init()
187 inp_buf ..... pointer to a buffer with 160 16-bit, left aligned samples
188 rpe_frame ... pointer to a rpe-ltp encoded frame buffer. Has length of 76.
189 The samples are 16-bit, right-aligned.
190
191 Return value:
192 ~~~~~~~~~~~~~
193 None.
194
195 Prototype: in rpeltp.h
196 ~~~~~~~~~~
197
198 Original author:
199 ~~~~~~~~~~~~~~~~
200 Simao Ferraz de Campos Neto
201 DDS/Pr11 Tel: +55-192-39-6637
202 CPqD/Telebras Fax: +55-192-39-6125
203 13088-061 Campinas SP Brazil E-mail: <simao@cpqd.ansp.br>
204
205 Log of changes:
206 ~~~~~~~~~~~~~~~
207 12.Apr.94 v.1.0 created.
208
209 ------------------------------------------------------------------------
210 */
211 void rpeltp_encode(rpe_state, inp_buf, rpe_frame)
212 gsm rpe_state;
213 short *inp_buf, *rpe_frame;
214 {
215 gsm_frame rpe_packed_frame;
216
217 /* Run both and save decoded samples */
218 gsm_encode(rpe_state, inp_buf, rpe_packed_frame);
219 gsm_explode(rpe_state, rpe_packed_frame, rpe_frame);
220 }
221
222 /* ................... End of rpeltp_encode() ......................... */
223
224
225 /*
226 ------------------------------------------------------------------------
227 void gsm_state *rpeltp_decode (gsm_state *rpe_state, short *rpe_frame,
228 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ short *out_buf);
229
230
231 Description:
232 ~~~~~~~~~~~~
233 Decode the input rpe-ltp encoded frame buffer rpe_buf with 76 righ-aligned
234 16-bit samples, generating 160 decoded 16-bit, left-aligned linear
235 2's-complement samples with 13-bit resolution, i.e., the lower 3 bits of
236 each input sample are zeroed. These are saved in out_buf.
237
238 The rpe-ltp frame buffer rpe_frame sample has the sequence specified by
239 the `parameter number' in Table 1.1 of the Rec.GSM-06.10.
240
241 Variables:
242 ~~~~~~~~~~
243 rpe_state ... state variable initialized by a previous call to rpeltp_init()
244 rpe_frame ... pointer to a rpe-ltp encoded frame buffer. Has length of 76.
245 The samples are 16-bit, right-aligned.
246 out_buf ..... pointer to the decode sample's buffer with 160 16-bit,
247 left aligned samples
248
249 Return value:
250 ~~~~~~~~~~~~~
251 None.
252
253 Prototype: in rpeltp.h
254 ~~~~~~~~~~
255
256 Original author:
257 ~~~~~~~~~~~~~~~~
258 Simao Ferraz de Campos Neto
259 DDS/Pr11 Tel: +55-192-39-6637
260 CPqD/Telebras Fax: +55-192-39-6125
261 13088-061 Campinas SP Brazil E-mail: <simao@cpqd.ansp.br>
262
263 Log of changes:
264 ~~~~~~~~~~~~~~~
265 12.Apr.94 v.1.0 created.
266
267 ------------------------------------------------------------------------
268 */
269 void rpeltp_decode(rpe_state, rpe_frame, out_buf)
270 gsm rpe_state;
271 short *out_buf, *rpe_frame;
272 {
273 gsm_frame rpe_packed_frame;
274
275 /* Pack frame, run only the decoder and save the decoded samples */
276 gsm_implode(rpe_state, rpe_frame, rpe_packed_frame);
277 gsm_decode(rpe_state, rpe_packed_frame, out_buf);
278 }
279
280 /* ................... End of rpeltp_decode() ......................... */
281
282 /* -------------------------- END OF RPELTP.C ------------------------ */

Repositories maintained by Peter Meerwald, pmeerw@pmeerw.net.