1/* -----------------------------------------------------------------------------
2Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4© Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5Forschung e.V. All rights reserved.
6
7 1.    INTRODUCTION
8The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10scheme for digital audio. This FDK AAC Codec software is intended to be used on
11a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14general perceptual audio codecs. AAC-ELD is considered the best-performing
15full-bandwidth communications codec by independent studies and is widely
16deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17specifications.
18
19Patent licenses for necessary patent claims for the FDK AAC Codec (including
20those of Fraunhofer) may be obtained through Via Licensing
21(www.vialicensing.com) or through the respective patent owners individually for
22the purpose of encoding or decoding bit streams in products that are compliant
23with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24Android devices already license these patent claims through Via Licensing or
25directly from the patent owners, and therefore FDK AAC Codec software may
26already be covered under those patent licenses when it is used for those
27licensed purposes only.
28
29Commercially-licensed AAC software libraries, including floating-point versions
30with enhanced sound quality, are also available from Fraunhofer. Users are
31encouraged to check the Fraunhofer website for additional applications
32information and documentation.
33
342.    COPYRIGHT LICENSE
35
36Redistribution and use in source and binary forms, with or without modification,
37are permitted without payment of copyright license fees provided that you
38satisfy the following conditions:
39
40You must retain the complete text of this software license in redistributions of
41the FDK AAC Codec or your modifications thereto in source code form.
42
43You must retain the complete text of this software license in the documentation
44and/or other materials provided with redistributions of the FDK AAC Codec or
45your modifications thereto in binary form. You must make available free of
46charge copies of the complete source code of the FDK AAC Codec and your
47modifications thereto to recipients of copies in binary form.
48
49The name of Fraunhofer may not be used to endorse or promote products derived
50from this library without prior written permission.
51
52You may not charge copyright license fees for anyone to use, copy or distribute
53the FDK AAC Codec software or your modifications thereto.
54
55Your modified versions of the FDK AAC Codec must carry prominent notices stating
56that you changed the software and the date of any change. For modified versions
57of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59AAC Codec Library for Android."
60
613.    NO PATENT LICENSE
62
63NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65Fraunhofer provides no warranty of patent non-infringement with respect to this
66software.
67
68You may use this FDK AAC Codec software or modifications thereto only for
69purposes that are authorized by appropriate patent licenses.
70
714.    DISCLAIMER
72
73This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75including but not limited to the implied warranties of merchantability and
76fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78or consequential damages, including but not limited to procurement of substitute
79goods or services; loss of use, data, or profits, or business interruption,
80however caused and on any theory of liability, whether in contract, strict
81liability, or tort (including negligence), arising in any way out of the use of
82this software, even if advised of the possibility of such damage.
83
845.    CONTACT INFORMATION
85
86Fraunhofer Institute for Integrated Circuits IIS
87Attention: Audio and Multimedia Departments - FDK AAC LL
88Am Wolfsmantel 33
8991058 Erlangen, Germany
90
91www.iis.fraunhofer.de/amm
92amm-info@iis.fraunhofer.de
93----------------------------------------------------------------------------- */
94
95/******************* Library for basic calculation routines ********************
96
97   Author(s):   M. Lohwasser, M. Gayer
98
99   Description:
100
101*******************************************************************************/
102
103#include "fft_rad2.h"
104
105#include "scramble.h"
106
107#define __FFT_RAD2_CPP__
108
109#if defined(__arm__)
110#include "arm/fft_rad2_arm.cpp"
111
112#elif defined(__GNUC__) && defined(__mips__) && defined(__mips_dsp)
113#include "mips/fft_rad2_mips.cpp"
114
115#endif
116
117/*****************************************************************************
118
119    functionname: dit_fft (analysis)
120    description:  dit-tukey-algorithm
121                  scrambles data at entry
122                  i.e. loop is made with scrambled data
123    returns:
124    input:
125    output:
126
127*****************************************************************************/
128
129#ifndef FUNCTION_dit_fft
130
131void dit_fft(FIXP_DBL *x, const INT ldn, const FIXP_STP *trigdata,
132             const INT trigDataSize) {
133  const INT n = 1 << ldn;
134  INT trigstep, i, ldm;
135
136  C_ALLOC_ALIGNED_CHECK(x);
137
138  scramble(x, n);
139  /*
140   * 1+2 stage radix 4
141   */
142
143  for (i = 0; i < n * 2; i += 8) {
144    FIXP_DBL a00, a10, a20, a30;
145    a00 = (x[i + 0] + x[i + 2]) >> 1; /* Re A + Re B */
146    a10 = (x[i + 4] + x[i + 6]) >> 1; /* Re C + Re D */
147    a20 = (x[i + 1] + x[i + 3]) >> 1; /* Im A + Im B */
148    a30 = (x[i + 5] + x[i + 7]) >> 1; /* Im C + Im D */
149
150    x[i + 0] = a00 + a10; /* Re A' = Re A + Re B + Re C + Re D */
151    x[i + 4] = a00 - a10; /* Re C' = Re A + Re B - Re C - Re D */
152    x[i + 1] = a20 + a30; /* Im A' = Im A + Im B + Im C + Im D */
153    x[i + 5] = a20 - a30; /* Im C' = Im A + Im B - Im C - Im D */
154
155    a00 = a00 - x[i + 2]; /* Re A - Re B */
156    a10 = a10 - x[i + 6]; /* Re C - Re D */
157    a20 = a20 - x[i + 3]; /* Im A - Im B */
158    a30 = a30 - x[i + 7]; /* Im C - Im D */
159
160    x[i + 2] = a00 + a30; /* Re B' = Re A - Re B + Im C - Im D */
161    x[i + 6] = a00 - a30; /* Re D' = Re A - Re B - Im C + Im D */
162    x[i + 3] = a20 - a10; /* Im B' = Im A - Im B - Re C + Re D */
163    x[i + 7] = a20 + a10; /* Im D' = Im A - Im B + Re C - Re D */
164  }
165
166  for (ldm = 3; ldm <= ldn; ++ldm) {
167    INT m = (1 << ldm);
168    INT mh = (m >> 1);
169    INT j, r;
170
171    trigstep = ((trigDataSize << 2) >> ldm);
172
173    FDK_ASSERT(trigstep > 0);
174
175    /* Do first iteration with c=1.0 and s=0.0 separately to avoid loosing to
176       much precision. Beware: The impact on the overal FFT precision is rather
177       large. */
178    { /* block 1 */
179
180      j = 0;
181
182      for (r = 0; r < n; r += m) {
183        INT t1 = (r + j) << 1;
184        INT t2 = t1 + (mh << 1);
185        FIXP_DBL vr, vi, ur, ui;
186
187        // cplxMultDiv2(&vi, &vr, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
188        vi = x[t2 + 1] >> 1;
189        vr = x[t2] >> 1;
190
191        ur = x[t1] >> 1;
192        ui = x[t1 + 1] >> 1;
193
194        x[t1] = ur + vr;
195        x[t1 + 1] = ui + vi;
196
197        x[t2] = ur - vr;
198        x[t2 + 1] = ui - vi;
199
200        t1 += mh;
201        t2 = t1 + (mh << 1);
202
203        // cplxMultDiv2(&vr, &vi, x[t2+1], x[t2], (FIXP_SGL)1.0, (FIXP_SGL)0.0);
204        vr = x[t2 + 1] >> 1;
205        vi = x[t2] >> 1;
206
207        ur = x[t1] >> 1;
208        ui = x[t1 + 1] >> 1;
209
210        x[t1] = ur + vr;
211        x[t1 + 1] = ui - vi;
212
213        x[t2] = ur - vr;
214        x[t2 + 1] = ui + vi;
215      }
216
217    } /* end of  block 1 */
218
219    for (j = 1; j < mh / 4; ++j) {
220      FIXP_STP cs;
221
222      cs = trigdata[j * trigstep];
223
224      for (r = 0; r < n; r += m) {
225        INT t1 = (r + j) << 1;
226        INT t2 = t1 + (mh << 1);
227        FIXP_DBL vr, vi, ur, ui;
228
229        cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], cs);
230
231        ur = x[t1] >> 1;
232        ui = x[t1 + 1] >> 1;
233
234        x[t1] = ur + vr;
235        x[t1 + 1] = ui + vi;
236
237        x[t2] = ur - vr;
238        x[t2 + 1] = ui - vi;
239
240        t1 += mh;
241        t2 = t1 + (mh << 1);
242
243        cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], cs);
244
245        ur = x[t1] >> 1;
246        ui = x[t1 + 1] >> 1;
247
248        x[t1] = ur + vr;
249        x[t1 + 1] = ui - vi;
250
251        x[t2] = ur - vr;
252        x[t2 + 1] = ui + vi;
253
254        /* Same as above but for t1,t2 with j>mh/4 and thus cs swapped */
255        t1 = (r + mh / 2 - j) << 1;
256        t2 = t1 + (mh << 1);
257
258        cplxMultDiv2(&vi, &vr, x[t2], x[t2 + 1], cs);
259
260        ur = x[t1] >> 1;
261        ui = x[t1 + 1] >> 1;
262
263        x[t1] = ur + vr;
264        x[t1 + 1] = ui - vi;
265
266        x[t2] = ur - vr;
267        x[t2 + 1] = ui + vi;
268
269        t1 += mh;
270        t2 = t1 + (mh << 1);
271
272        cplxMultDiv2(&vr, &vi, x[t2], x[t2 + 1], cs);
273
274        ur = x[t1] >> 1;
275        ui = x[t1 + 1] >> 1;
276
277        x[t1] = ur - vr;
278        x[t1 + 1] = ui - vi;
279
280        x[t2] = ur + vr;
281        x[t2 + 1] = ui + vi;
282      }
283    }
284
285    { /* block 2 */
286      j = mh / 4;
287
288      for (r = 0; r < n; r += m) {
289        INT t1 = (r + j) << 1;
290        INT t2 = t1 + (mh << 1);
291        FIXP_DBL vr, vi, ur, ui;
292
293        cplxMultDiv2(&vi, &vr, x[t2 + 1], x[t2], STC(0x5a82799a),
294                     STC(0x5a82799a));
295
296        ur = x[t1] >> 1;
297        ui = x[t1 + 1] >> 1;
298
299        x[t1] = ur + vr;
300        x[t1 + 1] = ui + vi;
301
302        x[t2] = ur - vr;
303        x[t2 + 1] = ui - vi;
304
305        t1 += mh;
306        t2 = t1 + (mh << 1);
307
308        cplxMultDiv2(&vr, &vi, x[t2 + 1], x[t2], STC(0x5a82799a),
309                     STC(0x5a82799a));
310
311        ur = x[t1] >> 1;
312        ui = x[t1 + 1] >> 1;
313
314        x[t1] = ur + vr;
315        x[t1 + 1] = ui - vi;
316
317        x[t2] = ur - vr;
318        x[t2 + 1] = ui + vi;
319      }
320    } /* end of block 2 */
321  }
322}
323
324#endif
325