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