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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 /**************************** AAC decoder library ******************************
96 
97    Author(s):   Josef Hoepfl
98 
99    Description: long/short-block decoding
100 
101 *******************************************************************************/
102 
103 #ifndef BLOCK_H
104 #define BLOCK_H
105 
106 #include "common_fix.h"
107 
108 #include "channelinfo.h"
109 #include "FDK_bitstream.h"
110 
111 /* PNS (of block) */
112 void CPns_Read(CPnsData *pPnsData, HANDLE_FDK_BITSTREAM bs,
113                const CodeBookDescription *hcb, SHORT *pScaleFactor,
114                UCHAR global_gain, int band, int group);
115 
116 void CPns_Apply(const CPnsData *pPnsData, const CIcsInfo *pIcsInfo,
117                 SPECTRAL_PTR pSpectrum, const SHORT *pSpecScale,
118                 const SHORT *pScaleFactor,
119                 const SamplingRateInfo *pSamplingRateInfo,
120                 const INT granuleLength, const int channel);
121 
122 void CBlock_ApplyNoise(CAacDecoderChannelInfo *pAacDecoderChannelInfo,
123                        SamplingRateInfo *pSamplingRateInfo, ULONG *nfRandomSeed,
124                        UCHAR *band_is_noise);
125 
126 /* TNS (of block) */
127 /*!
128   \brief Read tns data-present flag from bitstream
129 
130   The function reads the data-present flag for tns from
131   the bitstream.
132 
133   \return  none
134 */
135 void CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs, CTnsData *pTnsData);
136 
137 void CTns_ReadDataPresentUsac(HANDLE_FDK_BITSTREAM hBs, CTnsData *pTnsData0,
138                               CTnsData *pTnsData1, UCHAR *ptns_on_lr,
139                               const CIcsInfo *pIcsInfo, const UINT flags,
140                               const UINT elFlags, const int fCommonWindow);
141 
142 AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs, CTnsData *pTnsData,
143                             const CIcsInfo *pIcsInfo, const UINT flags);
144 
145 void CTns_Apply(CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
146                 const CIcsInfo *pIcsInfo, SPECTRAL_PTR pSpectralCoefficient,
147                 const SamplingRateInfo *pSamplingRateInfo,
148                 const INT granuleLength, const UCHAR nbands,
149                 const UCHAR igf_active, const UINT flags);
150 
151 /* Block */
152 
153 LONG CBlock_GetEscape(HANDLE_FDK_BITSTREAM bs, const LONG q);
154 
155 /**
156  * \brief Read scale factor data. See chapter 4.6.2.3.2 of ISO/IEC 14496-3.
157  *        The SF_OFFSET = 100 value referenced in chapter 4.6.2.3.3 is already
158  * substracted from the scale factor values. Also includes PNS data reading.
159  * \param bs bit stream handle data source
160  * \param pAacDecoderChannelInfo channel context info were decoded data is
161  * stored into.
162  * \param flags the decoder flags.
163  */
164 AAC_DECODER_ERROR CBlock_ReadScaleFactorData(
165     CAacDecoderChannelInfo *pAacDecoderChannelInfo, HANDLE_FDK_BITSTREAM bs,
166     const UINT flags);
167 
168 /**
169  * \brief Read Huffman encoded spectral data.
170  * \param pAacDecoderChannelInfo channel context info.
171  * \param pSamplingRateInfo sampling rate info (sfb offsets).
172  * \param flags syntax flags.
173  */
174 AAC_DECODER_ERROR CBlock_ReadSpectralData(
175     HANDLE_FDK_BITSTREAM bs, CAacDecoderChannelInfo *pAacDecoderChannelInfo,
176     const SamplingRateInfo *pSamplingRateInfo, const UINT flags);
177 
178 /**
179  * \brief Read Arithmetic encoded spectral data.
180  * \param pAacDecoderChannelInfo channel context info.
181  * \param pAacDecoderStaticChannelInfo static channel context info.
182  * \param pSamplingRateInfo sampling rate info (sfb offsets).
183  * \param frame_length spectral window length.
184  * \param flags syntax flags.
185  * \return error code.
186  */
187 AAC_DECODER_ERROR CBlock_ReadAcSpectralData(
188     HANDLE_FDK_BITSTREAM hBs, CAacDecoderChannelInfo *pAacDecoderChannelInfo,
189     CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
190     const SamplingRateInfo *pSamplingRateInfo, const UINT frame_length,
191     const UINT flags);
192 
193 AAC_DECODER_ERROR CBlock_ReadSectionData(
194     HANDLE_FDK_BITSTREAM bs, CAacDecoderChannelInfo *pAacDecoderChannelInfo,
195     const SamplingRateInfo *pSamplingRateInfo, const UINT flags);
196 
197 /**
198  * \brief find a common exponent (shift factor) for all sfb in each Spectral
199  * window, and store them into CAacDecoderChannelInfo::specScale.
200  * \param pAacDecoderChannelInfo channel context info.
201  * \param UCHAR maxSfbs maximum number of SFBs to be processed (might differ
202  * from pAacDecoderChannelInfo->icsInfo.MaxSfBands)
203  * \param pSamplingRateInfo sampling rate info (sfb offsets).
204  */
205 void CBlock_ScaleSpectralData(CAacDecoderChannelInfo *pAacDecoderChannelInfo,
206                               UCHAR maxSfbs,
207                               SamplingRateInfo *pSamplingRateInfo);
208 
209 /**
210  * \brief Apply TNS and PNS tools.
211  */
212 void ApplyTools(CAacDecoderChannelInfo *pAacDecoderChannelInfo[],
213                 const SamplingRateInfo *pSamplingRateInfo, const UINT flags,
214                 const UINT elFlags, const int channel, const int maybe_jstereo);
215 
216 /**
217  * \brief Transform MDCT spectral data into time domain
218  */
219 void CBlock_FrequencyToTime(
220     CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
221     CAacDecoderChannelInfo *pAacDecoderChannelInfo, FIXP_PCM outSamples[],
222     const SHORT frameLen, const int frameOk, FIXP_DBL *pWorkBuffer1,
223     UINT elFlags, INT elCh);
224 
225 /**
226  * \brief Transform double lapped MDCT (AAC-ELD) spectral data into time domain.
227  */
228 void CBlock_FrequencyToTimeLowDelay(
229     CAacDecoderStaticChannelInfo *pAacDecoderStaticChannelInfo,
230     CAacDecoderChannelInfo *pAacDecoderChannelInfo, FIXP_PCM outSamples[],
231     const short frameLen);
232 
233 AAC_DECODER_ERROR CBlock_InverseQuantizeSpectralData(
234     CAacDecoderChannelInfo *pAacDecoderChannelInfo,
235     SamplingRateInfo *pSamplingRateInfo, UCHAR *band_is_noise,
236     UCHAR active_band_search);
237 
238 /**
239  * \brief Calculate 2^(lsb/4) * value^(4/3)
240  * \param pValue pointer to quantized value. The inverse quantized result is
241  * stored back here.
242  * \param lsb 2 LSBs of the scale factor (scaleFactor % 4) applied as power 2
243  * factor to the resulting inverse quantized value.
244  * \return the exponent of the result (mantissa) stored into *pValue.
245  */
246 FDK_INLINE
EvaluatePower43(FIXP_DBL * pValue,UINT lsb)247 int EvaluatePower43(FIXP_DBL *pValue, UINT lsb) {
248   FIXP_DBL value;
249   UINT freeBits;
250   UINT exponent;
251 
252   value = *pValue;
253   freeBits = fNormz(value);
254   exponent = DFRACT_BITS - freeBits;
255   FDK_ASSERT(exponent < 14);
256 
257   UINT x = (((int)value << freeBits) >> 19);
258   UINT tableIndex = (x & 0x0FFF) >> 4;
259   FIXP_DBL invQVal;
260 
261   x = x & 0x0F;
262 
263   UINT r0 = (LONG)InverseQuantTable[tableIndex + 0];
264   UINT r1 = (LONG)InverseQuantTable[tableIndex + 1];
265   USHORT nx = 16 - x;
266   UINT temp = (r0)*nx + (r1)*x;
267   invQVal = (FIXP_DBL)temp;
268 
269   FDK_ASSERT(lsb < 4);
270   *pValue = fMultDiv2(invQVal, MantissaTable[lsb][exponent]);
271 
272   /* + 1 compensates fMultDiv2(). */
273   return ExponentTable[lsb][exponent] + 1;
274 }
275 
276 /* Recalculate gain */
277 FIXP_DBL get_gain(const FIXP_DBL *x, const FIXP_DBL *y, int n);
278 
279 /**
280  * \brief determine the required shift scale for the given quantized value and
281  * scale (factor % 4) value.
282  */
GetScaleFromValue(FIXP_DBL value,unsigned int lsb)283 FDK_INLINE int GetScaleFromValue(FIXP_DBL value, unsigned int lsb) {
284   if (value != (FIXP_DBL)0) {
285     int scale = EvaluatePower43(&value, lsb);
286     return CntLeadingZeros(value) - scale - 2;
287   } else
288     return 0; /* Return zero, because its useless to scale a zero value, saves
289                  workload and avoids scaling overshifts. */
290 }
291 
292 /*!
293   \brief Read huffman codeword
294 
295   The function reads the huffman codeword from the bitstream and
296   returns the index value.
297 
298   \return  index value
299 */
CBlock_DecodeHuffmanWord(HANDLE_FDK_BITSTREAM bs,const CodeBookDescription * hcb)300 inline int CBlock_DecodeHuffmanWord(
301     HANDLE_FDK_BITSTREAM bs,        /*!< pointer to bitstream */
302     const CodeBookDescription *hcb) /*!< pointer to codebook description */
303 {
304   UINT val;
305   UINT index = 0;
306   const USHORT(*CodeBook)[HuffmanEntries] = hcb->CodeBook;
307 
308   while (1) {
309     val = CodeBook[index]
310                   [FDKreadBits(bs, HuffmanBits)]; /* Expensive memory access */
311 
312     if ((val & 1) == 0) {
313       index = val >> 2;
314       continue;
315     } else {
316       if (val & 2) {
317         FDKpushBackCache(bs, 1);
318       }
319 
320       val >>= 2;
321       break;
322     }
323   }
324 
325   return val;
326 }
CBlock_DecodeHuffmanWordCB(HANDLE_FDK_BITSTREAM bs,const USHORT (* CodeBook)[HuffmanEntries])327 inline int CBlock_DecodeHuffmanWordCB(
328     HANDLE_FDK_BITSTREAM bs, /*!< pointer to bitstream */
329     const USHORT (
330         *CodeBook)[HuffmanEntries]) /*!< pointer to codebook description */
331 {
332   UINT index = 0;
333 
334   while (1) {
335     index = CodeBook[index][FDKread2Bits(bs)]; /* Expensive memory access */
336     if (index & 1) break;
337     index >>= 2;
338   }
339   if (index & 2) {
340     FDKpushBackCache(bs, 1);
341   }
342   return index >> 2;
343 }
344 
345 #endif /* #ifndef BLOCK_H */
346