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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: temporal noise shaping tool
100 
101 *******************************************************************************/
102 
103 #include "aacdec_tns.h"
104 #include "aac_rom.h"
105 #include "FDK_bitstream.h"
106 #include "channelinfo.h"
107 
108 #include "FDK_lpc.h"
109 
110 #define TNS_MAXIMUM_ORDER_AAC 12
111 
112 /*!
113   \brief Reset tns data
114 
115   The function resets the tns data
116 
117   \return  none
118 */
CTns_Reset(CTnsData * pTnsData)119 void CTns_Reset(CTnsData *pTnsData) {
120   /* Note: the following FDKmemclear should not be required. */
121   FDKmemclear(pTnsData->Filter,
122               TNS_MAX_WINDOWS * TNS_MAXIMUM_FILTERS * sizeof(CFilter));
123   FDKmemclear(pTnsData->NumberOfFilters, TNS_MAX_WINDOWS * sizeof(UCHAR));
124   pTnsData->DataPresent = 0;
125   pTnsData->Active = 0;
126 }
127 
CTns_ReadDataPresentFlag(HANDLE_FDK_BITSTREAM bs,CTnsData * pTnsData)128 void CTns_ReadDataPresentFlag(
129     HANDLE_FDK_BITSTREAM bs, /*!< pointer to bitstream */
130     CTnsData *pTnsData)      /*!< pointer to aac decoder channel info */
131 {
132   pTnsData->DataPresent = (UCHAR)FDKreadBits(bs, 1);
133 }
134 
135 /*!
136   \brief Read tns data from bitstream
137 
138   The function reads the elements for tns from
139   the bitstream.
140 
141   \return  none
142 */
CTns_Read(HANDLE_FDK_BITSTREAM bs,CTnsData * pTnsData,const CIcsInfo * pIcsInfo,const UINT flags)143 AAC_DECODER_ERROR CTns_Read(HANDLE_FDK_BITSTREAM bs, CTnsData *pTnsData,
144                             const CIcsInfo *pIcsInfo, const UINT flags) {
145   UCHAR n_filt, order;
146   UCHAR length, coef_res, coef_compress;
147   UCHAR window;
148   UCHAR wins_per_frame;
149   UCHAR isLongFlag;
150   UCHAR start_window;
151   AAC_DECODER_ERROR ErrorStatus = AAC_DEC_OK;
152 
153   if (!pTnsData->DataPresent) {
154     return ErrorStatus;
155   }
156 
157   {
158     start_window = 0;
159     wins_per_frame = GetWindowsPerFrame(pIcsInfo);
160     isLongFlag = IsLongBlock(pIcsInfo);
161   }
162 
163   pTnsData->GainLd = 0;
164 
165   for (window = start_window; window < wins_per_frame; window++) {
166     pTnsData->NumberOfFilters[window] = n_filt =
167         (UCHAR)FDKreadBits(bs, isLongFlag ? 2 : 1);
168 
169     if (n_filt) {
170       int index;
171       UCHAR nextstopband;
172 
173       coef_res = (UCHAR)FDKreadBits(bs, 1);
174 
175       nextstopband = GetScaleFactorBandsTotal(pIcsInfo);
176 
177       for (index = 0; index < n_filt; index++) {
178         CFilter *filter = &pTnsData->Filter[window][index];
179 
180         length = (UCHAR)FDKreadBits(bs, isLongFlag ? 6 : 4);
181 
182         if (length > nextstopband) {
183           length = nextstopband;
184         }
185 
186         filter->StartBand = nextstopband - length;
187         filter->StopBand = nextstopband;
188         nextstopband = filter->StartBand;
189 
190         if (flags & (AC_USAC | AC_RSVD50 | AC_RSV603DA)) {
191           /* max(Order) = 15 (long), 7 (short) */
192           filter->Order = order = (UCHAR)FDKreadBits(bs, isLongFlag ? 4 : 3);
193         } else {
194           filter->Order = order = (UCHAR)FDKreadBits(bs, isLongFlag ? 5 : 3);
195 
196           if (filter->Order > TNS_MAXIMUM_ORDER) {
197             ErrorStatus = AAC_DEC_TNS_READ_ERROR;
198             return ErrorStatus;
199           }
200         }
201 
202         FDK_ASSERT(order <=
203                    TNS_MAXIMUM_ORDER); /* avoid illegal memory access */
204         if (order) {
205           UCHAR coef, s_mask;
206           UCHAR i;
207           SCHAR n_mask;
208 
209           static const UCHAR sgn_mask[] = {0x2, 0x4, 0x8};
210           static const SCHAR neg_mask[] = {~0x3, ~0x7, ~0xF};
211 
212           filter->Direction = FDKreadBits(bs, 1) ? -1 : 1;
213 
214           coef_compress = (UCHAR)FDKreadBits(bs, 1);
215 
216           filter->Resolution = coef_res + 3;
217 
218           s_mask = sgn_mask[coef_res + 1 - coef_compress];
219           n_mask = neg_mask[coef_res + 1 - coef_compress];
220 
221           for (i = 0; i < order; i++) {
222             coef = (UCHAR)FDKreadBits(bs, filter->Resolution - coef_compress);
223             filter->Coeff[i] = (coef & s_mask) ? (coef | n_mask) : coef;
224           }
225           pTnsData->GainLd = 4;
226         }
227       }
228     }
229   }
230 
231   pTnsData->Active = 1;
232 
233   return ErrorStatus;
234 }
235 
CTns_ReadDataPresentUsac(HANDLE_FDK_BITSTREAM hBs,CTnsData * pTnsData0,CTnsData * pTnsData1,UCHAR * ptns_on_lr,const CIcsInfo * pIcsInfo,const UINT flags,const UINT elFlags,const int fCommonWindow)236 void CTns_ReadDataPresentUsac(HANDLE_FDK_BITSTREAM hBs, CTnsData *pTnsData0,
237                               CTnsData *pTnsData1, UCHAR *ptns_on_lr,
238                               const CIcsInfo *pIcsInfo, const UINT flags,
239                               const UINT elFlags, const int fCommonWindow) {
240   int common_tns = 0;
241 
242   if (fCommonWindow) {
243     common_tns = FDKreadBit(hBs);
244   }
245   { *ptns_on_lr = FDKreadBit(hBs); }
246   if (common_tns) {
247     pTnsData0->DataPresent = 1;
248     CTns_Read(hBs, pTnsData0, pIcsInfo, flags);
249 
250     pTnsData0->DataPresent = 0;
251     pTnsData0->Active = 1;
252     *pTnsData1 = *pTnsData0;
253   } else {
254     int tns_present_both;
255 
256     tns_present_both = FDKreadBit(hBs);
257     if (tns_present_both) {
258       pTnsData0->DataPresent = 1;
259       pTnsData1->DataPresent = 1;
260     } else {
261       pTnsData1->DataPresent = FDKreadBit(hBs);
262       pTnsData0->DataPresent = !pTnsData1->DataPresent;
263     }
264   }
265 }
266 
267 /*!
268   \brief Apply tns to spectral lines
269 
270   The function applies the tns to the spectrum,
271 
272   \return  none
273 */
CTns_Apply(CTnsData * RESTRICT pTnsData,const CIcsInfo * pIcsInfo,SPECTRAL_PTR pSpectralCoefficient,const SamplingRateInfo * pSamplingRateInfo,const INT granuleLength,const UCHAR nbands,const UCHAR igf_active,const UINT flags)274 void CTns_Apply(CTnsData *RESTRICT pTnsData, /*!< pointer to aac decoder info */
275                 const CIcsInfo *pIcsInfo, SPECTRAL_PTR pSpectralCoefficient,
276                 const SamplingRateInfo *pSamplingRateInfo,
277                 const INT granuleLength, const UCHAR nbands,
278                 const UCHAR igf_active, const UINT flags) {
279   int window, index, start, stop, size, start_window, wins_per_frame;
280 
281   if (pTnsData->Active) {
282     C_AALLOC_SCRATCH_START(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER)
283 
284     {
285       start_window = 0;
286       wins_per_frame = GetWindowsPerFrame(pIcsInfo);
287     }
288 
289     for (window = start_window; window < wins_per_frame; window++) {
290       FIXP_DBL *pSpectrum;
291 
292       { pSpectrum = SPEC(pSpectralCoefficient, window, granuleLength); }
293 
294       for (index = 0; index < pTnsData->NumberOfFilters[window]; index++) {
295         CFilter *filter = &pTnsData->Filter[window][index];
296 
297         if (filter->Order > 0) {
298           FIXP_TCC *pCoeff;
299           UCHAR tns_max_bands;
300 
301           pCoeff = coeff;
302           if (filter->Resolution == 3) {
303             int i;
304             for (i = 0; i < filter->Order; i++)
305               *pCoeff++ = FDKaacDec_tnsCoeff3[filter->Coeff[i] + 4];
306           } else {
307             int i;
308             for (i = 0; i < filter->Order; i++)
309               *pCoeff++ = FDKaacDec_tnsCoeff4[filter->Coeff[i] + 8];
310           }
311 
312           switch (granuleLength) {
313             case 480:
314               tns_max_bands =
315                   tns_max_bands_tbl_480[pSamplingRateInfo->samplingRateIndex];
316               break;
317             case 512:
318               tns_max_bands =
319                   tns_max_bands_tbl_512[pSamplingRateInfo->samplingRateIndex];
320               break;
321             default:
322               tns_max_bands = GetMaximumTnsBands(
323                   pIcsInfo, pSamplingRateInfo->samplingRateIndex);
324               /* See redefinition of TNS_MAX_BANDS table */
325               if ((flags & (AC_USAC | AC_RSVD50 | AC_RSV603DA)) &&
326                   (pSamplingRateInfo->samplingRateIndex > 5)) {
327                 tns_max_bands += 1;
328               }
329               break;
330           }
331 
332           start = fixMin(fixMin(filter->StartBand, tns_max_bands), nbands);
333 
334           start = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[start];
335 
336           if (igf_active) {
337             stop = fixMin(filter->StopBand, nbands);
338           } else {
339             stop = fixMin(fixMin(filter->StopBand, tns_max_bands), nbands);
340           }
341 
342           stop = GetScaleFactorBandOffsets(pIcsInfo, pSamplingRateInfo)[stop];
343 
344           size = stop - start;
345 
346           if (size) {
347             C_ALLOC_SCRATCH_START(state, FIXP_DBL, TNS_MAXIMUM_ORDER)
348 
349             FDKmemclear(state, TNS_MAXIMUM_ORDER * sizeof(FIXP_DBL));
350             CLpc_SynthesisLattice(pSpectrum + start, size, 0, 0,
351                                   filter->Direction, coeff, filter->Order,
352                                   state);
353 
354             C_ALLOC_SCRATCH_END(state, FIXP_DBL, TNS_MAXIMUM_ORDER)
355           }
356         }
357       }
358     }
359     C_AALLOC_SCRATCH_END(coeff, FIXP_TCC, TNS_MAXIMUM_ORDER)
360   }
361 }
362