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/****************************************************************************************
19Portions 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)
26Permission to distribute, modify and use this file under the standard license
27terms 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
151void 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
213void 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