1 /* ------------------------------------------------------------------
2 * Copyright (C) 1998-2009 PacketVideo
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
13 * express or implied.
14 * See the License for the specific language governing permissions
15 * and limitations under the License.
16 * -------------------------------------------------------------------
17 */
18 /****************************************************************************************
19 Portions of this file are derived from the following 3GPP standard:
20
21 3GPP TS 26.073
22 ANSI-C code for the Adaptive Multi-Rate (AMR) speech codec
23 Available from http://www.3gpp.org
24
25 (C) 2004, 3GPP Organizational Partners (ARIB, ATIS, CCSA, ETSI, TTA, TTC)
26 Permission to distribute, modify and use this file under the standard license
27 terms listed above has been obtained from the copyright holder.
28 ****************************************************************************************/
29 /*
30 ------------------------------------------------------------------------------
31
32
33
34 Pathname: ./audio/gsm-amr/c/src/int_lsf.c
35
36 Date: 04/20/2000
37
38 ------------------------------------------------------------------------------
39 REVISION HISTORY
40
41 Description: Put file into template and first pass at optimization.
42
43 Description: Made changes based on comments from the review meeting. Used
44 pointers instead of index addressing in the arrays.
45
46 Description: Added type definition to the input/output section. Fixed tabs.
47 Deleted pseudo-code.
48
49 Description: Synchronized file with UMTS versin 3.2.0. Updated coding
50 template. Removed unnecessary include files.
51
52 Description: Made the following changes per comments from Phase 2/3 review:
53 1. Modified FOR loops to count down.
54 2. Made some cosmetic changes in the Pseudo-code section.
55
56 Description: Changed to pass in overflow flag pointer to the add() routine.
57
58 Description: Replaced "int" and/or "char" with OSCL defined types.
59
60 Description:
61
62 ------------------------------------------------------------------------------
63 */
64
65 /*----------------------------------------------------------------------------
66 ; INCLUDES
67 ----------------------------------------------------------------------------*/
68 #include "int_lsf.h"
69 #include "typedef.h"
70 #include "basic_op.h"
71 #include "cnst.h"
72
73 /*----------------------------------------------------------------------------
74 ; MACROS
75 ; Define module specific macros here
76 ----------------------------------------------------------------------------*/
77
78
79 /*----------------------------------------------------------------------------
80 ; DEFINES
81 ; Include all pre-processor statements here. Include conditional
82 ; compile variables also.
83 ----------------------------------------------------------------------------*/
84
85
86 /*----------------------------------------------------------------------------
87 ; LOCAL FUNCTION DEFINITIONS
88 ; Function Prototype declaration
89 ----------------------------------------------------------------------------*/
90
91
92 /*----------------------------------------------------------------------------
93 ; LOCAL STORE/BUFFER/POINTER DEFINITIONS
94 ; Variable declaration - defined here and used outside this module
95 ----------------------------------------------------------------------------*/
96
97
98 /*
99 ------------------------------------------------------------------------------
100 FUNCTION NAME: Int_lsf
101 ------------------------------------------------------------------------------
102 INPUT AND OUTPUT DEFINITIONS
103
104 Inputs:
105 lsf_old = LSF vector at the 4th SF of past frame (Word16)
106 lsf_new = LSF vector at the 4th SF of present frame (Word16)
107 i_subfr = Current subframe (equal to 0,40,80 or 120) (Word16)
108 lsf_out = interpolated LSF parameters for current subframe (Word16)
109
110 Outputs:
111 lsf_out = new interpolated LSF parameters for current subframe
112 pOverflow = pointer of type Flag * to overflow indicator.
113
114 Returns:
115 None.
116
117 Global Variables Used:
118 None.
119
120 Local Variables Needed:
121 None.
122
123 ------------------------------------------------------------------------------
124 FUNCTION DESCRIPTION
125
126 This function interpolates the LSFs for selected subframe.
127 The 20 ms speech frame is divided into 4 subframes. The LSFs are
128 interpolated at the 1st, 2nd and 3rd subframe and only forwarded
129 at the 4th subframe.
130
131 |------|------|------|------|
132 sf1 sf2 sf3 sf4
133 F0 F1
134
135 sf1: 3/4 F0 + 1/4 F1 sf3: 1/4 F0 + 3/4 F1
136 sf2: 1/2 F0 + 1/2 F1 sf4: F1
137
138 ------------------------------------------------------------------------------
139 REQUIREMENTS
140
141 None.
142
143 ------------------------------------------------------------------------------
144 REFERENCES
145
146 int_lsf.c, UMTS GSM AMR speech codec, R99 - Version 3.2.0, March 2, 2001
147
148 ------------------------------------------------------------------------------
149 PSEUDO-CODE
150
151 void Int_lsf(
152 Word16 lsf_old[], // i : LSF vector at the 4th SF of past frame
153 Word16 lsf_new[], // i : LSF vector at the 4th SF of present frame
154 Word16 i_subfr, // i : Pointer to current sf (equal to 0,40,80 or 120)
155 Word16 lsf_out[] // o : interpolated LSF parameters for current sf
156 )
157 {
158 Word16 i;
159
160 if ( i_subfr == 0 )
161 {
162 for (i = 0; i < M; i++) {
163 lsf_out[i] = add(sub(lsf_old[i], shr(lsf_old[i], 2)),
164 shr(lsf_new[i], 2));
165 }
166 }
167 else if ( sub(i_subfr, 40) == 0 )
168 {
169 for (i = 0; i < M; i++) {
170 lsf_out[i] = add(shr(lsf_old[i],1), shr(lsf_new[i], 1) );
171 }
172 }
173 else if ( sub(i_subfr, 80) == 0 )
174 {
175 for (i = 0; i < M; i++) {
176 lsf_out[i] = add(shr(lsf_old[i], 2),
177 sub(lsf_new[i], shr(lsf_new[i], 2)));
178 }
179 }
180 else if ( sub(i_subfr, 120) == 0 )
181 {
182 for (i = 0; i < M; i++) {
183 lsf_out[i] = lsf_new[i];
184 }
185 }
186
187 return;
188 }
189
190 ------------------------------------------------------------------------------
191 RESOURCES USED [optional]
192
193 When the code is written for a specific target processor the
194 the resources used should be documented below.
195
196 HEAP MEMORY USED: x bytes
197
198 STACK MEMORY USED: x bytes
199
200 CLOCK CYCLES: (cycle count equation for this function) + (variable
201 used to represent cycle count for each subroutine
202 called)
203 where: (cycle count variable) = cycle count for [subroutine
204 name]
205
206 ------------------------------------------------------------------------------
207 CAUTION [optional]
208 [State any special notes, constraints or cautions for users of this function]
209
210 ------------------------------------------------------------------------------
211 */
212
Int_lsf(Word16 lsf_old[],Word16 lsf_new[],Word16 i_subfr,Word16 lsf_out[],Flag * pOverflow)213 void Int_lsf(
214 Word16 lsf_old[], /* i : LSF vector at the 4th SF of past frame */
215 Word16 lsf_new[], /* i : LSF vector at the 4th SF of present frame */
216 Word16 i_subfr, /* i : Current sf (equal to 0,40,80 or 120) */
217 Word16 lsf_out[], /* o : interpolated LSF parameters for current sf */
218 Flag *pOverflow /* o : flag set if overflow occurs */
219 )
220 {
221 Word16 i;
222 Word16 temp1;
223 Word16 temp2;
224
225 if (i_subfr == 0)
226 {
227 for (i = M - 1; i >= 0; i--)
228 {
229 if (*(lsf_old + i) < 0)
230 {
231 temp1 = ~(~(*(lsf_old + i)) >> 2);
232 }
233 else
234 {
235 temp1 = *(lsf_old + i) >> 2;
236 }
237 if (*(lsf_new + i) < 0)
238 {
239 temp2 = ~(~(*(lsf_new + i)) >> 2);
240 }
241 else
242 {
243 temp2 = *(lsf_new + i) >> 2;
244 }
245 *(lsf_out + i) = add((Word16)(*(lsf_old + i) - temp1),
246 (Word16)temp2,
247 pOverflow);
248 }
249 }
250
251 else if (i_subfr == 40)
252 {
253 for (i = M - 1; i >= 0; i--)
254 {
255 if (*(lsf_old + i) < 0)
256 {
257 temp1 = ~(~(*(lsf_old + i)) >> 1);
258 }
259 else
260 {
261 temp1 = *(lsf_old + i) >> 1;
262 }
263 if (*(lsf_new + i) < 0)
264 {
265 temp2 = ~(~(*(lsf_new + i)) >> 1);
266 }
267 else
268 {
269 temp2 = *(lsf_new + i) >> 1;
270 }
271 *(lsf_out + i) = add(
272 temp1,
273 temp2,
274 pOverflow);
275 }
276 }
277
278 else if (i_subfr == 80)
279 {
280 for (i = M - 1; i >= 0; i--)
281 {
282 if (*(lsf_old + i) < 0)
283 {
284 temp1 = ~(~(*(lsf_old + i)) >> 2);
285 }
286 else
287 {
288 temp1 = *(lsf_old + i) >> 2;
289 }
290 if (*(lsf_new + i) < 0)
291 {
292 temp2 = ~(~(*(lsf_new + i)) >> 2);
293 }
294 else
295 {
296 temp2 = *(lsf_new + i) >> 2;
297 }
298 *(lsf_out + i) = add((Word16)temp1,
299 (Word16)(*(lsf_new + i) - temp2),
300 pOverflow);
301
302 }
303 }
304
305 else if (i_subfr == 120)
306 {
307 for (i = M - 1; i >= 0; i--)
308 {
309 *(lsf_out + i) = *(lsf_new + i);
310 }
311 }
312
313 return;
314 }
315
316