1
2 /* -----------------------------------------------------------------------------------------------------------
3 Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5 � Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
6 All rights reserved.
7
8 1. INTRODUCTION
9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16 of the MPEG specifications.
17
18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
24
25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27 applications information and documentation.
28
29 2. COPYRIGHT LICENSE
30
31 Redistribution and use in source and binary forms, with or without modification, are permitted without
32 payment of copyright license fees provided that you satisfy the following conditions:
33
34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35 your modifications thereto in source code form.
36
37 You must retain the complete text of this software license in the documentation and/or other materials
38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40 modifications thereto to recipients of copies in binary form.
41
42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43 prior written permission.
44
45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46 software or your modifications thereto.
47
48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49 and 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
53 3. NO PATENT LICENSE
54
55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57 respect to this software.
58
59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60 by appropriate patent licenses.
61
62 4. DISCLAIMER
63
64 This 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
66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69 or business interruption, however caused and on any theory of liability, whether in contract, strict
70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
71 advised of the possibility of such damage.
72
73 5. CONTACT INFORMATION
74
75 Fraunhofer Institute for Integrated Circuits IIS
76 Attention: Audio and Multimedia Departments - FDK AAC LL
77 Am Wolfsmantel 33
78 91058 Erlangen, Germany
79
80 www.iis.fraunhofer.de/amm
81 amm-info@iis.fraunhofer.de
82 ----------------------------------------------------------------------------------------------------------- */
83
84 /*****************************************************************************
85
86 Description: FDKaacLdEnc_MdctTransform480:
87 The module FDKaacLdEnc_MdctTransform will perform the MDCT.
88 The MDCT supports the sine window and
89 the zero padded window. The algorithm of the MDCT
90 can be divided in Windowing, PreModulation, Fft and
91 PostModulation.
92
93 ******************************************************************************/
94
95 #include "transform.h"
96
97 #include "dct.h"
98 #include "psy_const.h"
99 #include "aacEnc_rom.h"
100 #include "FDK_tools_rom.h"
101
FDKaacEnc_Transform_Real(const INT_PCM * pTimeData,FIXP_DBL * RESTRICT mdctData,const INT blockType,const INT windowShape,INT * prevWindowShape,const INT frameLength,INT * mdctData_e,INT filterType,FIXP_DBL * RESTRICT overlapAddBuffer)102 INT FDKaacEnc_Transform_Real (const INT_PCM * pTimeData,
103 FIXP_DBL *RESTRICT mdctData,
104 const INT blockType,
105 const INT windowShape,
106 INT *prevWindowShape,
107 const INT frameLength,
108 INT *mdctData_e,
109 INT filterType
110 ,FIXP_DBL * RESTRICT overlapAddBuffer
111 )
112 {
113 const INT_PCM * RESTRICT timeData;
114
115 INT i;
116 /* tl: transform length
117 fl: left window slope length
118 nl: left window slope offset
119 fr: right window slope length
120 nr: right window slope offset
121 See FDK_tools/doc/intern/mdct.tex for more detail. */
122 int tl, fl, nl, fr, nr;
123
124 const FIXP_WTP * RESTRICT pLeftWindowPart;
125 const FIXP_WTP * RESTRICT pRightWindowPart;
126
127 /*
128 * MDCT scale:
129 * + 1: fMultDiv2() in windowing.
130 * + 1: Because of factor 1/2 in Princen-Bradley compliant windowed TDAC.
131 */
132 *mdctData_e = 1+1;
133
134 tl = frameLength;
135 timeData = pTimeData;
136
137 switch( blockType ) {
138 case LONG_WINDOW:
139 {
140 int offset = (windowShape == LOL_WINDOW) ? ((frameLength * 3)>>2) : 0;
141 fl = frameLength - offset;
142 fr = frameLength - offset;
143 }
144 break;
145 case STOP_WINDOW:
146 fl = frameLength >> 3;
147 fr = frameLength;
148 break;
149 case START_WINDOW: /* or StopStartSequence */
150 fl = frameLength;
151 fr = frameLength >> 3;
152 break;
153 case SHORT_WINDOW:
154 fl = fr = frameLength >> 3;
155 tl >>= 3;
156 timeData = pTimeData + 3*fl + (fl/2);
157 break;
158 default:
159 FDK_ASSERT(0);
160 return -1;
161 break;
162 }
163
164 /* Taken from FDK_tools/src/mdct.cpp Derive NR and NL */
165 nr = (tl - fr)>>1;
166 nl = (tl - fl)>>1;
167
168 pLeftWindowPart = FDKgetWindowSlope(fl, *prevWindowShape);
169 pRightWindowPart = FDKgetWindowSlope(fr, windowShape);
170
171 /* windowing */
172 if (filterType != FB_ELD)
173 {
174 /* Left window slope offset */
175 for (i=0; i<nl ; i++)
176 {
177 #if SAMPLE_BITS == DFRACT_BITS /* SPC_BITS and DFRACT_BITS should be equal. */
178 mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] >> ( 1 );
179 #else
180 mdctData[(tl/2)+i] = - (FIXP_DBL) timeData[tl-i-1] << (DFRACT_BITS - SAMPLE_BITS - 1);
181 #endif
182 }
183 /* Left window slope */
184 for (i=0; i<fl/2; i++)
185 {
186 FIXP_DBL tmp0;
187 tmp0 = fMultDiv2((FIXP_PCM)timeData[i+nl], pLeftWindowPart[i].v.im);
188 mdctData[(tl/2)+i+nl] = fMultSubDiv2(tmp0, (FIXP_PCM)timeData[tl-nl-i-1], pLeftWindowPart[i].v.re);
189 }
190
191 /* Right window slope offset */
192 for(i=0; i<nr; i++)
193 {
194 #if SAMPLE_BITS == DFRACT_BITS /* This should be SPC_BITS instead of DFRACT_BITS. */
195 mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] >> (1);
196 #else
197 mdctData[(tl/2)-1-i] = - (FIXP_DBL) timeData[tl+i] << (DFRACT_BITS - SAMPLE_BITS - 1);
198 #endif
199 }
200 /* Right window slope */
201 for (i=0; i<fr/2; i++)
202 {
203 FIXP_DBL tmp1;
204 tmp1 = fMultDiv2((FIXP_PCM)timeData[tl+nr+i], pRightWindowPart[i].v.re);
205 mdctData[(tl/2)-nr-i-1] = -fMultAddDiv2(tmp1, (FIXP_PCM)timeData[(tl*2)-nr-i-1], pRightWindowPart[i].v.im);
206 }
207 }
208
209 if (filterType == FB_ELD)
210 {
211 const FIXP_WTB *pWindowELD=NULL;
212 int i, N = frameLength, L = frameLength;
213
214 if (frameLength == 512) {
215 pWindowELD = ELDAnalysis512;
216 } else {
217 pWindowELD = ELDAnalysis480;
218 }
219
220 for(i=0;i<N/4;i++)
221 {
222 FIXP_DBL z0, outval;
223
224 z0 = (fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i])<< (WTS0-1)) + (fMult((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N/2+i])<< (WTS0-1));
225
226 outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1));
227 outval += (fMultDiv2((FIXP_PCM)timeData[L+N*3/4+i], pWindowELD[N+N/2+i]) >> (-WTS1) );
228 outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i])>> (-WTS2-1));
229
230 overlapAddBuffer[N/2+i] = overlapAddBuffer[i];
231
232 overlapAddBuffer[i] = z0;
233 mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
234
235 mdctData[N-1-i] = outval;
236 overlapAddBuffer[N+N/2-1-i] = outval;
237 }
238
239 for(i=N/4;i<N/2;i++)
240 {
241 FIXP_DBL z0, outval;
242
243 z0 = fMult((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N/2-1-i]) << (WTS0-1);
244
245 outval = (fMultDiv2((FIXP_PCM)timeData[L+N*3/4-1-i], pWindowELD[N+N/2-1-i]) >> (-WTS1)) ;
246 outval += (fMultDiv2(overlapAddBuffer[N/2+i], pWindowELD[2*N+i]) >> (-WTS2-1));
247
248 overlapAddBuffer[N/2+i] = overlapAddBuffer[i] + (fMult((FIXP_PCM)timeData[L-N/4+i], pWindowELD[N/2+i])<< (WTS0-1) );
249
250 overlapAddBuffer[i] = z0;
251 mdctData[i] = overlapAddBuffer[N/2+i] + (fMultDiv2(overlapAddBuffer[N+N/2-1-i], pWindowELD[2*N+N/2+i]) >> (-WTS2-1));
252
253 mdctData[N-1-i] = outval;
254 overlapAddBuffer[N+N/2-1-i] = outval;
255 }
256 }
257
258 dct_IV(mdctData, tl, mdctData_e);
259
260 *prevWindowShape = windowShape;
261
262 return 0;
263 }
264
265