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1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3 
4 © Copyright  1995 - 2019 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 /*********************** MPEG surround decoder library *************************
96 
97    Author(s):   Matthias Hildenbrand
98 
99    Description: USAC MPS212 Transient Steering Decorrelator (TSD)
100 
101 *******************************************************************************/
102 
103 #include "sac_tsd.h"
104 
105 #define TSD_START_BAND (7)
106 #define SIZE_S (4)
107 #define SIZE_C (5)
108 
109 /*** Tables ***/
110 RAM_ALIGN
111 LNK_SECTION_CONSTDATA
112 static const UCHAR nBitsTsdCW_32slots[32] = {
113     5,  9,  13, 16, 18, 20, 22, 24, 25, 26, 27, 28, 29, 29, 30, 30,
114     30, 29, 29, 28, 27, 26, 25, 24, 22, 20, 18, 16, 13, 9,  5,  0};
115 
116 RAM_ALIGN
117 LNK_SECTION_CONSTDATA
118 static const UCHAR nBitsTsdCW_64slots[64] = {
119     6,  11, 16, 20, 23, 27, 30, 33, 35, 38, 40, 42, 44, 46, 48, 49,
120     51, 52, 53, 55, 56, 57, 58, 58, 59, 60, 60, 60, 61, 61, 61, 61,
121     61, 61, 61, 60, 60, 60, 59, 58, 58, 57, 56, 55, 53, 52, 51, 49,
122     48, 46, 44, 42, 40, 38, 35, 33, 30, 27, 23, 20, 16, 11, 6,  0};
123 
124 RAM_ALIGN
125 LNK_SECTION_CONSTDATA
126 static const FIXP_DPK phiTsd[8] = {
127     {{(FIXP_DBL)0x7fffffff, (FIXP_DBL)0x00000000}},
128     {{(FIXP_DBL)0x5a82799a, (FIXP_DBL)0x5a82799a}},
129     {{(FIXP_DBL)0x00000000, (FIXP_DBL)0x7fffffff}},
130     {{(FIXP_DBL)0xa57d8666, (FIXP_DBL)0x5a82799a}},
131     {{(FIXP_DBL)0x80000000, (FIXP_DBL)0x00000000}},
132     {{(FIXP_DBL)0xa57d8666, (FIXP_DBL)0xa57d8666}},
133     {{(FIXP_DBL)0x00000000, (FIXP_DBL)0x80000000}},
134     {{(FIXP_DBL)0x5a82799a, (FIXP_DBL)0xa57d8666}}};
135 
136 /*** Static Functions ***/
longmult1(USHORT a[],USHORT b,USHORT d[],int len)137 static void longmult1(USHORT a[], USHORT b, USHORT d[], int len) {
138   int k;
139   ULONG tmp;
140   ULONG b0 = (ULONG)b;
141 
142   tmp = ((ULONG)a[0]) * b0;
143   d[0] = (USHORT)tmp;
144 
145   for (k = 1; k < len; k++) {
146     tmp = (tmp >> 16) + ((ULONG)a[k]) * b0;
147     d[k] = (USHORT)tmp;
148   }
149 }
150 
longdiv(USHORT b[],USHORT a,USHORT d[],USHORT * pr,int len)151 static void longdiv(USHORT b[], USHORT a, USHORT d[], USHORT *pr, int len) {
152   ULONG r;
153   ULONG tmp;
154   int k;
155 
156   FDK_ASSERT(a != 0);
157 
158   r = 0;
159 
160   for (k = len - 1; k >= 0; k--) {
161     tmp = ((ULONG)b[k]) + (r << 16);
162 
163     if (tmp) {
164       d[k] = (USHORT)(tmp / a);
165       r = tmp - d[k] * a;
166     } else {
167       d[k] = 0;
168     }
169   }
170   *pr = (USHORT)r;
171 }
172 
longsub(USHORT a[],USHORT b[],int lena,int lenb)173 static void longsub(USHORT a[], USHORT b[], int lena, int lenb) {
174   int h;
175   LONG carry = 0;
176 
177   FDK_ASSERT(lena >= lenb);
178   for (h = 0; h < lenb; h++) {
179     carry += ((LONG)a[h]) - ((LONG)b[h]);
180     a[h] = (USHORT)carry;
181     carry = carry >> 16;
182   }
183 
184   for (; h < lena; h++) {
185     carry = ((LONG)a[h]) + carry;
186     a[h] = (USHORT)carry;
187     carry = carry >> 16;
188   }
189 
190   FDK_ASSERT(carry ==
191              0); /* carry != 0 indicates subtraction underflow, e.g. b > a */
192   return;
193 }
194 
longcompare(USHORT a[],USHORT b[],int len)195 static int longcompare(USHORT a[], USHORT b[], int len) {
196   int i;
197 
198   for (i = len - 1; i > 0; i--) {
199     if (a[i] != b[i]) break;
200   }
201   return (a[i] >= b[i]) ? 1 : 0;
202 }
203 
isTrSlot(const TSD_DATA * pTsdData,const int ts)204 FDK_INLINE int isTrSlot(const TSD_DATA *pTsdData, const int ts) {
205   return (pTsdData->bsTsdTrPhaseData[ts] >= 0);
206 }
207 
208 /*** Public Functions ***/
TsdRead(HANDLE_FDK_BITSTREAM hBs,const int numSlots,TSD_DATA * pTsdData)209 int TsdRead(HANDLE_FDK_BITSTREAM hBs, const int numSlots, TSD_DATA *pTsdData) {
210   int nBitsTrSlots = 0;
211   int bsTsdNumTrSlots;
212   const UCHAR *nBitsTsdCW_tab = NULL;
213 
214   switch (numSlots) {
215     case 32:
216       nBitsTrSlots = 4;
217       nBitsTsdCW_tab = nBitsTsdCW_32slots;
218       break;
219     case 64:
220       nBitsTrSlots = 5;
221       nBitsTsdCW_tab = nBitsTsdCW_64slots;
222       break;
223     default:
224       return 1;
225   }
226 
227   /*** Read TempShapeData for bsTempShapeConfig == 3 ***/
228   pTsdData->bsTsdEnable = FDKreadBit(hBs);
229   if (!pTsdData->bsTsdEnable) {
230     return 0;
231   }
232 
233   /*** Parse/Decode TsdData() ***/
234   pTsdData->numSlots = numSlots;
235 
236   bsTsdNumTrSlots = FDKreadBits(hBs, nBitsTrSlots);
237 
238   /* Decode transient slot positions */
239   {
240     int nBitsTsdCW = (int)nBitsTsdCW_tab[bsTsdNumTrSlots];
241     SCHAR *phaseData = pTsdData->bsTsdTrPhaseData;
242     int p = bsTsdNumTrSlots + 1;
243     int k, h;
244     USHORT s[SIZE_S] = {0};
245     USHORT c[SIZE_C] = {0};
246     USHORT r[1];
247 
248     /* Init with TsdSepData[k] = 0 */
249     for (k = 0; k < numSlots; k++) {
250       phaseData[k] = -1; /* means TsdSepData[] = 0 */
251     }
252 
253     for (h = (SIZE_S - 1); h >= 0; h--) {
254       if (nBitsTsdCW > h * 16) {
255         s[h] = (USHORT)FDKreadBits(hBs, nBitsTsdCW - h * 16);
256         nBitsTsdCW = h * 16;
257       }
258     }
259 
260     /* c = prod_{h=1}^{p} (k-p+h)/h */
261     k = numSlots - 1;
262     c[0] = k - p + 1;
263     for (h = 2; h <= p; h++) {
264       longmult1(c, (k - p + h), c, 5); /* c *= k - p + h; */
265       longdiv(c, h, c, r, 5);          /* c /= h; */
266       FDK_ASSERT(*r == 0);
267     }
268 
269     /* go through all slots */
270     for (; k >= 0; k--) {
271       if (p > k) {
272         for (; k >= 0; k--) {
273           phaseData[k] = 1; /* means TsdSepData[] = 1 */
274         }
275         break;
276       }
277       if (longcompare(s, c, 4)) { /* (s >= c) */
278         longsub(s, c, 4, 4);      /* s -= c; */
279         phaseData[k] = 1;         /* means TsdSepData[] = 1 */
280         if (p == 1) {
281           break;
282         }
283         /* Update c for next iteration: c_new = c_old * p / k */
284         longmult1(c, p, c, 5);
285         p--;
286       } else {
287         /* Update c for next iteration: c_new = c_old * (k-p) / k */
288         longmult1(c, (k - p), c, 5);
289       }
290       longdiv(c, k, c, r, 5);
291       FDK_ASSERT(*r == 0);
292     }
293 
294     /* Read phase data */
295     for (k = 0; k < numSlots; k++) {
296       if (phaseData[k] == 1) {
297         phaseData[k] = FDKreadBits(hBs, 3);
298       }
299     }
300   }
301 
302   return 0;
303 }
304 
TsdGenerateNonTr(const int numHybridBands,const TSD_DATA * pTsdData,const int ts,FIXP_DBL * pVdirectReal,FIXP_DBL * pVdirectImag,FIXP_DBL * pVnonTrReal,FIXP_DBL * pVnonTrImag,FIXP_DBL ** ppDecorrInReal,FIXP_DBL ** ppDecorrInImag)305 void TsdGenerateNonTr(const int numHybridBands, const TSD_DATA *pTsdData,
306                       const int ts, FIXP_DBL *pVdirectReal,
307                       FIXP_DBL *pVdirectImag, FIXP_DBL *pVnonTrReal,
308                       FIXP_DBL *pVnonTrImag, FIXP_DBL **ppDecorrInReal,
309                       FIXP_DBL **ppDecorrInImag) {
310   int k = 0;
311 
312   if (!isTrSlot(pTsdData, ts)) {
313     /* Let allpass based decorrelator read from direct input. */
314     *ppDecorrInReal = pVdirectReal;
315     *ppDecorrInImag = pVdirectImag;
316     return;
317   }
318 
319   /* Generate nonTr input signal for allpass based decorrelator */
320   for (; k < TSD_START_BAND; k++) {
321     pVnonTrReal[k] = pVdirectReal[k];
322     pVnonTrImag[k] = pVdirectImag[k];
323   }
324   for (; k < numHybridBands; k++) {
325     pVnonTrReal[k] = (FIXP_DBL)0;
326     pVnonTrImag[k] = (FIXP_DBL)0;
327   }
328   *ppDecorrInReal = pVnonTrReal;
329   *ppDecorrInImag = pVnonTrImag;
330 }
331 
TsdApply(const int numHybridBands,const TSD_DATA * pTsdData,int * pTsdTs,const FIXP_DBL * pVdirectReal,const FIXP_DBL * pVdirectImag,FIXP_DBL * pDnonTrReal,FIXP_DBL * pDnonTrImag)332 void TsdApply(const int numHybridBands, const TSD_DATA *pTsdData, int *pTsdTs,
333               const FIXP_DBL *pVdirectReal, const FIXP_DBL *pVdirectImag,
334               FIXP_DBL *pDnonTrReal, FIXP_DBL *pDnonTrImag) {
335   const int ts = *pTsdTs;
336 
337   if (isTrSlot(pTsdData, ts)) {
338     int k;
339     const FIXP_DPK *phi = &phiTsd[pTsdData->bsTsdTrPhaseData[ts]];
340     FDK_ASSERT((pTsdData->bsTsdTrPhaseData[ts] >= 0) &&
341                (pTsdData->bsTsdTrPhaseData[ts] < 8));
342 
343     /* d = d_nonTr + v_direct * exp(j * bsTsdTrPhaseData[ts]/4 * pi ) */
344     for (k = TSD_START_BAND; k < numHybridBands; k++) {
345       FIXP_DBL tempReal, tempImag;
346       cplxMultDiv2(&tempReal, &tempImag, pVdirectReal[k], pVdirectImag[k],
347                    *phi);
348       pDnonTrReal[k] = SATURATE_LEFT_SHIFT(
349           (pDnonTrReal[k] >> 2) + (tempReal >> 1), 2, DFRACT_BITS);
350       pDnonTrImag[k] = SATURATE_LEFT_SHIFT(
351           (pDnonTrImag[k] >> 2) + (tempImag >> 1), 2, DFRACT_BITS);
352     }
353   }
354 
355   /* The modulo MAX_TSD_TIME_SLOTS operation is to avoid illegal memory accesses
356    * in case of errors. */
357   *pTsdTs = (ts + 1) & (MAX_TSD_TIME_SLOTS - 1);
358   return;
359 }
360