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):   Haricharan Lakshman, Manuel Jander
98 
99    Description: Trigonometric functions fixed point fractional implementation.
100 
101 *******************************************************************************/
102 
103 #if !defined(FDK_TRIGFCTS_H)
104 #define FDK_TRIGFCTS_H
105 
106 #include "common_fix.h"
107 
108 #include "FDK_tools_rom.h"
109 
110 /* Fixed point precision definitions */
111 #define Q(format) ((FIXP_DBL)(((LONG)1) << (format)))
112 
113 #ifndef M_PI
114 #define M_PI (3.14159265358979323846f)
115 #endif
116 
117 /*!
118  * Inverse tangent function.
119  */
120 
121 /* --- fixp_atan() ----    */
122 #define Q_ATANINP (25)  // Input in q25, Output in q30
123 #define Q_ATANOUT (30)
124 #define ATI_SF ((DFRACT_BITS - 1) - Q_ATANINP) /* 6  */
125 #define ATI_SCALE ((float)(1 << ATI_SF))
126 #define ATO_SF ((DFRACT_BITS - 1) - Q_ATANOUT) /* 1   ] -pi/2 .. pi/2 [ */
127 #define ATO_SCALE ((float)(1 << ATO_SF))
128 /* --- fixp_atan2() ---    */
129 #define Q_ATAN2OUT (29)
130 #define AT2O_SF ((DFRACT_BITS - 1) - Q_ATAN2OUT) /* 2   ] -pi   .. pi   ] */
131 #define AT2O_SCALE ((float)(1 << AT2O_SF))
132 // --------------------
133 
134 FIXP_DBL fixp_atan(FIXP_DBL x);
135 FIXP_DBL fixp_atan2(FIXP_DBL y, FIXP_DBL x);
136 
137 FIXP_DBL fixp_cos(FIXP_DBL x, int scale);
138 FIXP_DBL fixp_sin(FIXP_DBL x, int scale);
139 
140 #define FIXP_COS_SIN
141 
142 #include "FDK_tools_rom.h"
143 
144 #define SINETAB SineTable512
145 #define LD 9
146 
147 #ifndef FUNCTION_inline_fixp_cos_sin
148 
149 #define FUNCTION_inline_fixp_cos_sin
150 
151 /*
152  * Calculates coarse lookup index and sign for sine.
153  * Returns delta x residual.
154  */
fixp_sin_cos_residual_inline(FIXP_DBL x,int scale,FIXP_DBL * sine,FIXP_DBL * cosine)155 static inline FIXP_DBL fixp_sin_cos_residual_inline(FIXP_DBL x, int scale,
156                                                     FIXP_DBL *sine,
157                                                     FIXP_DBL *cosine) {
158   FIXP_DBL residual;
159   int s;
160   int shift = (31 - scale - LD - 1);
161   int ssign = 1;
162   int csign = 1;
163 
164   residual = fMult(x, FL2FXCONST_DBL(1.0 / M_PI));
165   s = ((LONG)residual) >> shift;
166 
167   residual &= ((1 << shift) - 1);
168   residual = fMult(residual, FL2FXCONST_DBL(M_PI / 4.0)) << 2;
169   residual <<= scale;
170 
171   /* Sine sign symmetry */
172   if (s & ((1 << LD) << 1)) {
173     ssign = -ssign;
174   }
175   /* Cosine sign symmetry */
176   if ((s + (1 << LD)) & ((1 << LD) << 1)) {
177     csign = -csign;
178   }
179 
180   s = fAbs(s);
181 
182   s &= (((1 << LD) << 1) - 1); /* Modulo PI */
183 
184   if (s > (1 << LD)) {
185     s = ((1 << LD) << 1) - s;
186   }
187 
188   {
189     LONG sl, cl;
190     /* Because of packed table */
191     if (s > (1 << (LD - 1))) {
192       FIXP_STP tmp;
193       /* Cosine/Sine simetry for angles greater than PI/4 */
194       s = (1 << LD) - s;
195       tmp = SINETAB[s];
196       sl = (LONG)tmp.v.re;
197       cl = (LONG)tmp.v.im;
198     } else {
199       FIXP_STP tmp;
200       tmp = SINETAB[s];
201       sl = (LONG)tmp.v.im;
202       cl = (LONG)tmp.v.re;
203     }
204 
205 #ifdef SINETABLE_16BIT
206     *sine = (FIXP_DBL)((sl * ssign) << (DFRACT_BITS - FRACT_BITS));
207     *cosine = (FIXP_DBL)((cl * csign) << (DFRACT_BITS - FRACT_BITS));
208 #else
209     /* scale down by 1 for overflow prevention. This is undone at the calling
210      * function. */
211     *sine = (FIXP_DBL)(sl * ssign) >> 1;
212     *cosine = (FIXP_DBL)(cl * csign) >> 1;
213 #endif
214   }
215 
216   return residual;
217 }
218 
219 /**
220  * \brief Calculate cosine and sine value each of 2 angles different angle
221  * values.
222  * \param x1 first angle value
223  * \param x2 second angle value
224  * \param scale exponent of x1 and x2
225  * \param out pointer to 4 FIXP_DBL locations, were the values cos(x1), sin(x1),
226  * cos(x2), sin(x2) will be stored into.
227  */
inline_fixp_cos_sin(FIXP_DBL x1,FIXP_DBL x2,const int scale,FIXP_DBL * out)228 static inline void inline_fixp_cos_sin(FIXP_DBL x1, FIXP_DBL x2,
229                                        const int scale, FIXP_DBL *out) {
230   FIXP_DBL residual, error0, error1, sine, cosine;
231   residual = fixp_sin_cos_residual_inline(x1, scale, &sine, &cosine);
232   error0 = fMultDiv2(sine, residual);
233   error1 = fMultDiv2(cosine, residual);
234 
235 #ifdef SINETABLE_16BIT
236   *out++ = cosine - (error0 << 1);
237   *out++ = sine + (error1 << 1);
238 #else
239   /* Undo downscaling by 1 which was done at fixp_sin_cos_residual_inline */
240   *out++ = SATURATE_LEFT_SHIFT(cosine - (error0 << 1), 1, DFRACT_BITS);
241   *out++ = SATURATE_LEFT_SHIFT(sine + (error1 << 1), 1, DFRACT_BITS);
242 #endif
243 
244   residual = fixp_sin_cos_residual_inline(x2, scale, &sine, &cosine);
245   error0 = fMultDiv2(sine, residual);
246   error1 = fMultDiv2(cosine, residual);
247 
248 #ifdef SINETABLE_16BIT
249   *out++ = cosine - (error0 << 1);
250   *out++ = sine + (error1 << 1);
251 #else
252   *out++ = SATURATE_LEFT_SHIFT(cosine - (error0 << 1), 1, DFRACT_BITS);
253   *out++ = SATURATE_LEFT_SHIFT(sine + (error1 << 1), 1, DFRACT_BITS);
254 #endif
255 }
256 #endif
257 
258 #endif /* !defined(FDK_TRIGFCTS_H) */
259