1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4 © Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5 Forschung e.V. All rights reserved.
6
7 1. INTRODUCTION
8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
11 a wide variety of Android devices.
12
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14 general perceptual audio codecs. AAC-ELD is considered the best-performing
15 full-bandwidth communications codec by independent studies and is widely
16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17 specifications.
18
19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
20 those of Fraunhofer) may be obtained through Via Licensing
21 (www.vialicensing.com) or through the respective patent owners individually for
22 the purpose of encoding or decoding bit streams in products that are compliant
23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24 Android devices already license these patent claims through Via Licensing or
25 directly from the patent owners, and therefore FDK AAC Codec software may
26 already be covered under those patent licenses when it is used for those
27 licensed purposes only.
28
29 Commercially-licensed AAC software libraries, including floating-point versions
30 with enhanced sound quality, are also available from Fraunhofer. Users are
31 encouraged to check the Fraunhofer website for additional applications
32 information and documentation.
33
34 2. COPYRIGHT LICENSE
35
36 Redistribution and use in source and binary forms, with or without modification,
37 are permitted without payment of copyright license fees provided that you
38 satisfy the following conditions:
39
40 You must retain the complete text of this software license in redistributions of
41 the FDK AAC Codec or your modifications thereto in source code form.
42
43 You must retain the complete text of this software license in the documentation
44 and/or other materials provided with redistributions of the FDK AAC Codec or
45 your modifications thereto in binary form. You must make available free of
46 charge copies of the complete source code of the FDK AAC Codec and your
47 modifications thereto to recipients of copies in binary form.
48
49 The name of Fraunhofer may not be used to endorse or promote products derived
50 from this library without prior written permission.
51
52 You may not charge copyright license fees for anyone to use, copy or distribute
53 the FDK AAC Codec software or your modifications thereto.
54
55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
56 that you changed the software and the date of any change. For modified versions
57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59 AAC Codec Library for Android."
60
61 3. NO PATENT LICENSE
62
63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65 Fraunhofer provides no warranty of patent non-infringement with respect to this
66 software.
67
68 You may use this FDK AAC Codec software or modifications thereto only for
69 purposes that are authorized by appropriate patent licenses.
70
71 4. DISCLAIMER
72
73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75 including but not limited to the implied warranties of merchantability and
76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78 or consequential damages, including but not limited to procurement of substitute
79 goods or services; loss of use, data, or profits, or business interruption,
80 however caused and on any theory of liability, whether in contract, strict
81 liability, or tort (including negligence), arising in any way out of the use of
82 this software, even if advised of the possibility of such damage.
83
84 5. CONTACT INFORMATION
85
86 Fraunhofer Institute for Integrated Circuits IIS
87 Attention: Audio and Multimedia Departments - FDK AAC LL
88 Am Wolfsmantel 33
89 91058 Erlangen, Germany
90
91 www.iis.fraunhofer.de/amm
92 amm-info@iis.fraunhofer.de
93 ----------------------------------------------------------------------------- */
94
95 /******************* Library for basic calculation routines ********************
96
97 Author(s):
98
99 Description: dit_fft ARM assembler replacements.
100
101 *******************************************************************************/
102
103 #ifndef __FFT_RAD2_CPP__
104 #error \
105 "Do not compile this file separately. It is included on demand from fft_rad2.cpp"
106 #endif
107
108 #ifndef FUNCTION_dit_fft
109 #if defined(SINETABLE_16BIT)
110
111 #define FUNCTION_dit_fft
112 #if defined(FUNCTION_dit_fft)
113
dit_fft(FIXP_DBL * x,const INT ldn,const FIXP_STP * trigdata,const INT trigDataSize)114 void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata,
115 const INT trigDataSize) {
116 const INT n = 1 << ldn;
117 INT i;
118
119 scramble(x, n);
120 /*
121 * 1+2 stage radix 4
122 */
123
124 for (i = 0; i < n * 2; i += 8) {
125 FIXP_DBL a00, a10, a20, a30;
126 a00 = (x[i + 0] + x[i + 2]) >> 1; /* Re A + Re B */
127 a10 = (x[i + 4] + x[i + 6]) >> 1; /* Re C + Re D */
128 a20 = (x[i + 1] + x[i + 3]) >> 1; /* Im A + Im B */
129 a30 = (x[i + 5] + x[i + 7]) >> 1; /* Im C + Im D */
130
131 x[i + 0] = a00 + a10; /* Re A' = Re A + Re B + Re C + Re D */
132 x[i + 4] = a00 - a10; /* Re C' = Re A + Re B - Re C - Re D */
133 x[i + 1] = a20 + a30; /* Im A' = Im A + Im B + Im C + Im D */
134 x[i + 5] = a20 - a30; /* Im C' = Im A + Im B - Im C - Im D */
135
136 a00 = a00 - x[i + 2]; /* Re A - Re B */
137 a10 = a10 - x[i + 6]; /* Re C - Re D */
138 a20 = a20 - x[i + 3]; /* Im A - Im B */
139 a30 = a30 - x[i + 7]; /* Im C - Im D */
140
141 x[i + 2] = a00 + a30; /* Re B' = Re A - Re B + Im C - Im D */
142 x[i + 6] = a00 - a30; /* Re D' = Re A - Re B - Im C + Im D */
143 x[i + 3] = a20 - a10; /* Im B' = Im A - Im B - Re C + Re D */
144 x[i + 7] = a20 + a10; /* Im D' = Im A - Im B + Re C - Re D */
145 }
146
147 INT mh = 1 << 1;
148 INT ldm = ldn - 2;
149 INT trigstep = trigDataSize;
150
151 do {
152 const FIXP_STP *pTrigData = trigdata;
153 INT j;
154
155 mh <<= 1;
156 trigstep >>= 1;
157
158 FDK_ASSERT(trigstep > 0);
159
160 /* Do first iteration with c=1.0 and s=0.0 separately to avoid loosing to
161 much precision. Beware: The impact on the overal FFT precision is rather
162 large. */
163 {
164 FIXP_DBL *xt1 = x;
165 int r = n;
166
167 do {
168 FIXP_DBL *xt2 = xt1 + (mh << 1);
169 /*
170 FIXP_DBL *xt1 = x+ ((r)<<1);
171 FIXP_DBL *xt2 = xt1 + (mh<<1);
172 */
173 FIXP_DBL vr, vi, ur, ui;
174
175 // cplxMultDiv2(&vi, &vr, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
176 vi = xt2[1] >> 1;
177 vr = xt2[0] >> 1;
178
179 ur = xt1[0] >> 1;
180 ui = xt1[1] >> 1;
181
182 xt1[0] = ur + vr;
183 xt1[1] = ui + vi;
184
185 xt2[0] = ur - vr;
186 xt2[1] = ui - vi;
187
188 xt1 += mh;
189 xt2 += mh;
190
191 // cplxMultDiv2(&vr, &vi, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
192 vr = xt2[1] >> 1;
193 vi = xt2[0] >> 1;
194
195 ur = xt1[0] >> 1;
196 ui = xt1[1] >> 1;
197
198 xt1[0] = ur + vr;
199 xt1[1] = ui - vi;
200
201 xt2[0] = ur - vr;
202 xt2[1] = ui + vi;
203
204 xt1 = xt2 + mh;
205 } while ((r = r - (mh << 1)) != 0);
206 }
207 for (j = 4; j < mh; j += 4) {
208 FIXP_DBL *xt1 = x + (j >> 1);
209 FIXP_SPK cs;
210 int r = n;
211
212 pTrigData += trigstep;
213 cs = *pTrigData;
214
215 do {
216 FIXP_DBL *xt2 = xt1 + (mh << 1);
217 FIXP_DBL vr, vi, ur, ui;
218
219 cplxMultDiv2(&vi, &vr, xt2[1], xt2[0], cs);
220
221 ur = xt1[0] >> 1;
222 ui = xt1[1] >> 1;
223
224 xt1[0] = ur + vr;
225 xt1[1] = ui + vi;
226
227 xt2[0] = ur - vr;
228 xt2[1] = ui - vi;
229
230 xt1 += mh;
231 xt2 += mh;
232
233 cplxMultDiv2(&vr, &vi, xt2[1], xt2[0], cs);
234
235 ur = xt1[0] >> 1;
236 ui = xt1[1] >> 1;
237
238 xt1[0] = ur + vr;
239 xt1[1] = ui - vi;
240
241 xt2[0] = ur - vr;
242 xt2[1] = ui + vi;
243
244 /* Same as above but for t1,t2 with j>mh/4 and thus cs swapped */
245 xt1 = xt1 - (j);
246 xt2 = xt1 + (mh << 1);
247
248 cplxMultDiv2(&vi, &vr, xt2[0], xt2[1], cs);
249
250 ur = xt1[0] >> 1;
251 ui = xt1[1] >> 1;
252
253 xt1[0] = ur + vr;
254 xt1[1] = ui - vi;
255
256 xt2[0] = ur - vr;
257 xt2[1] = ui + vi;
258
259 xt1 += mh;
260 xt2 += mh;
261
262 cplxMultDiv2(&vr, &vi, xt2[0], xt2[1], cs);
263
264 ur = xt1[0] >> 1;
265 ui = xt1[1] >> 1;
266
267 xt1[0] = ur - vr;
268 xt1[1] = ui - vi;
269
270 xt2[0] = ur + vr;
271 xt2[1] = ui + vi;
272
273 xt1 = xt2 + (j);
274 } while ((r = r - (mh << 1)) != 0);
275 }
276 {
277 FIXP_DBL *xt1 = x + (mh >> 1);
278 int r = n;
279
280 do {
281 FIXP_DBL *xt2 = xt1 + (mh << 1);
282 FIXP_DBL vr, vi, ur, ui;
283
284 cplxMultDiv2(&vi, &vr, xt2[1], xt2[0], STC(0x5a82799a),
285 STC(0x5a82799a));
286
287 ur = xt1[0] >> 1;
288 ui = xt1[1] >> 1;
289
290 xt1[0] = ur + vr;
291 xt1[1] = ui + vi;
292
293 xt2[0] = ur - vr;
294 xt2[1] = ui - vi;
295
296 xt1 += mh;
297 xt2 += mh;
298
299 cplxMultDiv2(&vr, &vi, xt2[1], xt2[0], STC(0x5a82799a),
300 STC(0x5a82799a));
301
302 ur = xt1[0] >> 1;
303 ui = xt1[1] >> 1;
304
305 xt1[0] = ur + vr;
306 xt1[1] = ui - vi;
307
308 xt2[0] = ur - vr;
309 xt2[1] = ui + vi;
310
311 xt1 = xt2 + mh;
312 } while ((r = r - (mh << 1)) != 0);
313 }
314 } while (--ldm != 0);
315 }
316
317 #endif /* if defined(FUNCTION_dit_fft) */
318
319 #endif /* if defined(SINETABLE_16BIT) */
320
321 #endif /* ifndef FUNCTION_dit_fft */
322