1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5© Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
6  All rights reserved.
7
8 1.    INTRODUCTION
9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16of the MPEG specifications.
17
18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20individually for the purpose of encoding or decoding bit streams in products that are compliant with
21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23software may already be covered under those patent licenses when it is used for those licensed purposes only.
24
25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27applications information and documentation.
28
292.    COPYRIGHT LICENSE
30
31Redistribution and use in source and binary forms, with or without modification, are permitted without
32payment of copyright license fees provided that you satisfy the following conditions:
33
34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35your modifications thereto in source code form.
36
37You must retain the complete text of this software license in the documentation and/or other materials
38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40modifications thereto to recipients of copies in binary form.
41
42The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43prior written permission.
44
45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46software or your modifications thereto.
47
48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49and the date of any change. For modified versions of the FDK AAC Codec, the term
50"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
51"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
52
533.    NO PATENT LICENSE
54
55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57respect to this software.
58
59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60by appropriate patent licenses.
61
624.    DISCLAIMER
63
64This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
65"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69or business interruption, however caused and on any theory of liability, whether in contract, strict
70liability, or tort (including negligence), arising in any way out of the use of this software, even if
71advised of the possibility of such damage.
72
735.    CONTACT INFORMATION
74
75Fraunhofer Institute for Integrated Circuits IIS
76Attention: Audio and Multimedia Departments - FDK AAC LL
77Am Wolfsmantel 33
7891058 Erlangen, Germany
79
80www.iis.fraunhofer.de/amm
81amm-info@iis.fraunhofer.de
82----------------------------------------------------------------------------------------------------------- */
83
84/***************************  Fraunhofer IIS FDK Tools  **********************
85
86   Author(s):
87   Description: dit_fft ARM assembler replacements.
88
89******************************************************************************/
90
91/* NEON optimized FFT currently builds only with RVCT toolchain */
92
93#ifndef FUNCTION_dit_fft
94
95/* If dit_fft was not yet defined by ARM-Cortex ... */
96
97#if defined(SINETABLE_16BIT)
98
99#define FUNCTION_dit_fft
100
101/*****************************************************************************
102
103   date:   28.07.2005   srl
104
105   Contents/description: dit-tukey-FFT-algorithm
106
107******************************************************************************/
108
109#if defined(FUNCTION_dit_fft)
110
111
112void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata, const INT trigDataSize)
113{
114    const INT n=1<<ldn;
115    INT i;
116
117    scramble(x,n);
118    /*
119     * 1+2 stage radix 4
120     */
121
122    for (i=0;i<n*2;i+=8)
123    {
124      FIXP_DBL a00, a10, a20, a30;
125      a00 = (x[i + 0] + x[i + 2])>>1;  /* Re A + Re B */
126      a10 = (x[i + 4] + x[i + 6])>>1;  /* Re C + Re D */
127      a20 = (x[i + 1] + x[i + 3])>>1;  /* Im A + Im B */
128      a30 = (x[i + 5] + x[i + 7])>>1;  /* Im C + Im D */
129
130      x[i + 0] = a00 + a10;       /* Re A' = Re A + Re B + Re C + Re D */
131      x[i + 4] = a00 - a10;       /* Re C' = Re A + Re B - Re C - Re D */
132      x[i + 1] = a20 + a30;       /* Im A' = Im A + Im B + Im C + Im D */
133      x[i + 5] = a20 - a30;       /* Im C' = Im A + Im B - Im C - Im D */
134
135      a00 = a00 - x[i + 2];       /* Re A - Re B */
136      a10 = a10 - x[i + 6];       /* Re C - Re D */
137      a20 = a20 - x[i + 3];       /* Im A - Im B */
138      a30 = a30 - x[i + 7];       /* Im C - Im D */
139
140      x[i + 2] = a00 + a30;       /* Re B' = Re A - Re B + Im C - Im D */
141      x[i + 6] = a00 - a30;       /* Re D' = Re A - Re B - Im C + Im D */
142      x[i + 3] = a20 - a10;       /* Im B' = Im A - Im B - Re C + Re D */
143      x[i + 7] = a20 + a10;       /* Im D' = Im A - Im B + Re C - Re D */
144    }
145
146    INT mh = 1 << 1;
147    INT ldm = ldn - 2;
148    INT trigstep = trigDataSize;
149
150    do
151    {
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 much precision.
161           Beware: The impact on the overal FFT precision is rather large. */
162        {
163            FIXP_DBL *xt1 = x;
164            int r = n;
165
166            do {
167                FIXP_DBL *xt2 = xt1 + (mh<<1);
168                /*
169                FIXP_DBL *xt1 = x+ ((r)<<1);
170                FIXP_DBL *xt2 = xt1 + (mh<<1);
171                */
172                FIXP_DBL vr,vi,ur,ui;
173
174                //cplxMultDiv2(&vi, &vr, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
175                vi = xt2[1]>>1;
176                vr = xt2[0]>>1;
177
178                ur = xt1[0]>>1;
179                ui = xt1[1]>>1;
180
181                xt1[0] = ur+vr;
182                xt1[1] = ui+vi;
183
184                xt2[0] = ur-vr;
185                xt2[1] = ui-vi;
186
187                xt1 += mh;
188                xt2 += mh;
189
190                //cplxMultDiv2(&vr, &vi, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
191                vr = xt2[1]>>1;
192                vi = xt2[0]>>1;
193
194                ur = xt1[0]>>1;
195                ui = xt1[1]>>1;
196
197                xt1[0] = ur+vr;
198                xt1[1] = ui-vi;
199
200                xt2[0] = ur-vr;
201                xt2[1] = ui+vi;
202
203                xt1 = xt2 + mh;
204            } while ((r=r-(mh<<1)) != 0);
205        }
206        for(j=4; j<mh; j+=4)
207        {
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            {
217                FIXP_DBL *xt2 = xt1 + (mh<<1);
218                FIXP_DBL vr,vi,ur,ui;
219
220                cplxMultDiv2(&vi, &vr, xt2[1], xt2[0], cs);
221
222                ur = xt1[0]>>1;
223                ui = xt1[1]>>1;
224
225                xt1[0] = ur+vr;
226                xt1[1] = ui+vi;
227
228                xt2[0] = ur-vr;
229                xt2[1] = ui-vi;
230
231                xt1 += mh;
232                xt2 += mh;
233
234                cplxMultDiv2(&vr, &vi, xt2[1], xt2[0], cs);
235
236                ur = xt1[0]>>1;
237                ui = xt1[1]>>1;
238
239                xt1[0] = ur+vr;
240                xt1[1] = ui-vi;
241
242                xt2[0] = ur-vr;
243                xt2[1] = ui+vi;
244
245                /* Same as above but for t1,t2 with j>mh/4 and thus cs swapped */
246                xt1 = xt1 - (j);
247                xt2 = xt1 + (mh<<1);
248
249                cplxMultDiv2(&vi, &vr, xt2[0], xt2[1], cs);
250
251                ur = xt1[0]>>1;
252                ui = xt1[1]>>1;
253
254                xt1[0] = ur+vr;
255                xt1[1] = ui-vi;
256
257                xt2[0] = ur-vr;
258                xt2[1] = ui+vi;
259
260                xt1 += mh;
261                xt2 += mh;
262
263                cplxMultDiv2(&vr, &vi, xt2[0], xt2[1], cs);
264
265                ur = xt1[0]>>1;
266                ui = xt1[1]>>1;
267
268                xt1[0] = ur-vr;
269                xt1[1] = ui-vi;
270
271                xt2[0] = ur+vr;
272                xt2[1] = ui+vi;
273
274                xt1 = xt2 + (j);
275            }  while ((r=r-(mh<<1)) != 0);
276        }
277        {
278            FIXP_DBL *xt1 = x + (mh>>1);
279            int r = n;
280
281            do
282            {
283                FIXP_DBL *xt2 = xt1 + (mh<<1);
284                FIXP_DBL vr,vi,ur,ui;
285
286                cplxMultDiv2(&vi, &vr, xt2[1], xt2[0], STC(0x5a82799a), STC(0x5a82799a));
287
288                ur = xt1[0]>>1;
289                ui = xt1[1]>>1;
290
291                xt1[0] = ur+vr;
292                xt1[1] = ui+vi;
293
294                xt2[0] = ur-vr;
295                xt2[1] = ui-vi;
296
297                xt1 += mh;
298                xt2 += mh;
299
300                cplxMultDiv2(&vr, &vi, xt2[1], xt2[0], STC(0x5a82799a), 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