1
2/* -----------------------------------------------------------------------------------------------------------
3Software 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
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/*****************************  MPEG-4 AAC Decoder  **************************
85
86   Author(s):   Josef Hoepfl
87   Description: long/short-block decoding
88
89******************************************************************************/
90
91#ifndef BLOCK_H
92#define BLOCK_H
93
94#include "common_fix.h"
95
96#include "channelinfo.h"
97#include "FDK_bitstream.h"
98
99/* PNS (of block) */
100void CPns_Read (CPnsData *pPnsData,
101                HANDLE_FDK_BITSTREAM bs,
102                const CodeBookDescription *hcb,
103                SHORT *pScaleFactor,
104                UCHAR global_gain,
105                int band,
106                int group);
107
108
109void CPns_Apply (const CPnsData *pPnsData,
110                 const CIcsInfo *pIcsInfo,
111                 SPECTRAL_PTR pSpectrum,
112                 const SHORT    *pSpecScale,
113                 const SHORT    *pScaleFactor,
114                 const SamplingRateInfo *pSamplingRateInfo,
115                 const INT granuleLength,
116                 const int channel);
117
118
119
120/* TNS (of block) */
121/*!
122  \brief Read tns data-present flag from bitstream
123
124  The function reads the data-present flag for tns from
125  the bitstream.
126
127  \return  none
128*/
129void CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs,
130                              CTnsData *pTnsData);
131
132void CTns_ReadDataPresentUsac(
133        HANDLE_FDK_BITSTREAM hBs,
134        CTnsData *pTnsData0,
135        CTnsData *pTnsData1,
136        const CIcsInfo *pIcsInfo,
137        const UINT flags,
138        const int fCommonWindow
139        );
140
141AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs,
142                            CTnsData *pTnsData,
143                            const CIcsInfo *pIcsInfo,
144                            const UINT flags);
145
146void CTns_Apply ( CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
147                  const CIcsInfo *pIcsInfo,
148                  SPECTRAL_PTR pSpectralCoefficient,
149                  const SamplingRateInfo *pSamplingRateInfo,
150                  const INT granuleLength);
151
152/* Block */
153
154LONG CBlock_GetEscape(HANDLE_FDK_BITSTREAM bs, const LONG q);
155
156/**
157 * \brief Read scale factor data. See chapter 4.6.2.3.2 of ISO/IEC 14496-3.
158 *        The SF_OFFSET = 100 value referenced in chapter 4.6.2.3.3 is already substracted
159 *        from the scale factor values. Also includes PNS data reading.
160 * \param bs bit stream handle data source
161 * \param pAacDecoderChannelInfo channel context info were decoded data is stored into.
162 * \param flags the decoder flags.
163 */
164AAC_DECODER_ERROR CBlock_ReadScaleFactorData(
165        CAacDecoderChannelInfo *pAacDecoderChannelInfo,
166        HANDLE_FDK_BITSTREAM bs,
167        const UINT flags
168        );
169
170/**
171 * \brief Read Huffman encoded spectral data.
172 * \param pAacDecoderChannelInfo channel context info.
173 * \param pSamplingRateInfo sampling rate info (sfb offsets).
174 * \param flags syntax flags.
175 */
176AAC_DECODER_ERROR  CBlock_ReadSpectralData(HANDLE_FDK_BITSTREAM bs,
177                                           CAacDecoderChannelInfo *pAacDecoderChannelInfo,
178                                           const SamplingRateInfo *pSamplingRateInfo,
179                                           const UINT  flags);
180
181
182AAC_DECODER_ERROR CBlock_ReadSectionData(HANDLE_FDK_BITSTREAM bs,
183                                         CAacDecoderChannelInfo *pAacDecoderChannelInfo,
184                                         const SamplingRateInfo *pSamplingRateInfo,
185                                         const UINT  flags);
186
187/**
188 * \brief find a common exponent (shift factor) for all sfb in each Spectral window, and store them into
189 *        CAacDecoderChannelInfo::specScale.
190 * \param pAacDecoderChannelInfo channel context info.
191 * \param pSamplingRateInfo sampling rate info (sfb offsets).
192 */
193void CBlock_ScaleSpectralData(CAacDecoderChannelInfo *pAacDecoderChannelInfo, SamplingRateInfo *pSamplingRateInfo);
194
195/**
196 * \brief Apply TNS and PNS tools.
197 */
198void ApplyTools ( CAacDecoderChannelInfo *pAacDecoderChannelInfo[],
199                  const SamplingRateInfo *pSamplingRateInfo,
200                  const UINT flags,
201                  const int channel );
202
203/**
204 * \brief Transform MDCT spectral data into time domain
205 */
206void CBlock_FrequencyToTime(CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
207                            CAacDecoderChannelInfo *pAacDecoderChannelInfo,
208                            INT_PCM outSamples[],
209                            const SHORT frameLen,
210                            const int stride,
211                            const int frameOk,
212                            FIXP_DBL *pWorkBuffer1);
213
214/**
215 * \brief Transform double lapped MDCT (AAC-ELD) spectral data into time domain.
216 */
217void CBlock_FrequencyToTimeLowDelay(CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
218                                    CAacDecoderChannelInfo *pAacDecoderChannelInfo,
219                                    INT_PCM outSamples[],
220                                    const short frameLen,
221                                    const char stride);
222
223AAC_DECODER_ERROR CBlock_InverseQuantizeSpectralData(CAacDecoderChannelInfo *pAacDecoderChannelInfo, SamplingRateInfo *pSamplingRateInfo);
224
225/**
226 * \brief Calculate 2^(lsb/4) * value^(4/3)
227 * \param pValue pointer to quantized value. The inverse quantized result is stored back here.
228 * \param lsb 2 LSBs of the scale factor (scaleFactor % 4) applied as power 2 factor to the
229 *        resulting inverse quantized value.
230 * \return the exponent of the result (mantissa) stored into *pValue.
231 */
232FDK_INLINE
233int EvaluatePower43 ( FIXP_DBL *pValue,
234                      UINT lsb )
235{
236  FIXP_DBL value;
237  UINT freeBits;
238  UINT exponent;
239
240  value = *pValue;
241  freeBits = fNormz (value) ;
242  exponent = DFRACT_BITS - freeBits ;
243  FDK_ASSERT (exponent < 14);
244
245  UINT x = (((int)value << freeBits) >> 19) ;
246  UINT tableIndex = (x & 0x0FFF) >> 4 ;
247  FIXP_DBL invQVal ;
248
249  x = x & 0x0F;
250
251  UINT r0=(LONG)InverseQuantTable [tableIndex+0];
252  UINT r1=(LONG)InverseQuantTable [tableIndex+1];
253  USHORT nx=16-x;
254  UINT temp=(r0)*nx+(r1)*x;
255  invQVal = (FIXP_DBL)temp;
256
257  FDK_ASSERT(lsb < 4);
258  *pValue = fMultDiv2 (invQVal, MantissaTable [lsb][exponent]) ;
259
260  /* + 1 compensates fMultDiv2(). */
261  return ExponentTable [lsb][exponent] + 1;
262}
263
264/**
265 * \brief determine the required shift scale for the given quantized value and scale (factor % 4) value.
266 */
267FDK_INLINE int GetScaleFromValue (FIXP_DBL value, unsigned int lsb)
268{
269  if (value!=(FIXP_DBL)0)
270  {
271    int scale = EvaluatePower43 (&value, lsb) ;
272    return CntLeadingZeros (value) - scale - 2 ;
273  }
274  else
275    return 0; /* Return zero, because its useless to scale a zero value, saves workload and avoids scaling overshifts. */
276}
277
278
279//#ifdef AACDEC_HUFFMANDECODER_ENABLE
280
281/*!
282  \brief Read huffman codeword
283
284  The function reads the huffman codeword from the bitstream and
285  returns the index value.
286
287  \return  index value
288*/
289inline int CBlock_DecodeHuffmanWord( HANDLE_FDK_BITSTREAM bs,                           /*!< pointer to bitstream */
290                                     const CodeBookDescription *hcb )                   /*!< pointer to codebook description */
291{
292  UINT val;
293  UINT index = 0;
294  const USHORT (*CodeBook) [HuffmanEntries] = hcb->CodeBook;
295
296  while (1)
297  {
298    val = CodeBook[index][FDKreadBits(bs,HuffmanBits)]; /* Expensive memory access */
299
300    if ((val & 1) == 0)
301    {
302      index = val>>2;
303      continue;
304    }
305    else
306    {
307      if (val & 2)
308      {
309        FDKpushBackCache(bs,1);
310      }
311
312      val >>= 2;
313      break;
314    }
315  }
316
317  return val;
318}
319
320//#endif /* AACDEC_HUFFMANDECODER_ENABLE */
321
322#endif /* #ifndef BLOCK_H */
323