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/*****************************************************************************
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
102INT 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