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/*! 85 \file 86 \brief FDK Fixed Point Arithmetic Library Interface 87*/ 88 89#ifndef __TRANSCENDENT_H 90#define __TRANSCENDENT_H 91 92#include "sbrdecoder.h" 93#include "sbr_rom.h" 94 95/************************************************************************/ 96/*! 97 \brief Get number of octaves between frequencies a and b 98 99 The Result is scaled with 1/8. 100 The valid range for a and b is 1 to LOG_DUALIS_TABLE_SIZE. 101 102 \return ld(a/b) / 8 103*/ 104/************************************************************************/ 105static inline FIXP_SGL FDK_getNumOctavesDiv8(INT a, /*!< lower band */ 106 INT b) /*!< upper band */ 107{ 108 return ( (SHORT)((LONG)(CalcLdInt(b) - CalcLdInt(a))>>(FRACT_BITS-3)) ); 109} 110 111 112/************************************************************************/ 113/*! 114 \brief Add two values given by mantissa and exponent. 115 116 Mantissas are in fract format with values between 0 and 1. <br> 117 The base for exponents is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> 118*/ 119/************************************************************************/ 120inline void FDK_add_MantExp(FIXP_SGL a_m, /*!< Mantissa of 1st operand a */ 121 SCHAR a_e, /*!< Exponent of 1st operand a */ 122 FIXP_SGL b_m, /*!< Mantissa of 2nd operand b */ 123 SCHAR b_e, /*!< Exponent of 2nd operand b */ 124 FIXP_SGL *ptrSum_m, /*!< Mantissa of result */ 125 SCHAR *ptrSum_e) /*!< Exponent of result */ 126{ 127 FIXP_DBL accu; 128 int shift; 129 int shiftAbs; 130 131 FIXP_DBL shiftedMantissa; 132 FIXP_DBL otherMantissa; 133 134 /* Equalize exponents of the summands. 135 For the smaller summand, the exponent is adapted and 136 for compensation, the mantissa is shifted right. */ 137 138 shift = (int)(a_e - b_e); 139 140 shiftAbs = (shift>0)? shift : -shift; 141 shiftAbs = (shiftAbs < DFRACT_BITS-1)? shiftAbs : DFRACT_BITS-1; 142 shiftedMantissa = (shift>0)? (FX_SGL2FX_DBL(b_m) >> shiftAbs) : (FX_SGL2FX_DBL(a_m) >> shiftAbs); 143 otherMantissa = (shift>0)? FX_SGL2FX_DBL(a_m) : FX_SGL2FX_DBL(b_m); 144 *ptrSum_e = (shift>0)? a_e : b_e; 145 146 accu = (shiftedMantissa >> 1) + (otherMantissa >> 1); 147 /* shift by 1 bit to avoid overflow */ 148 149 if ( (accu >= (FL2FXCONST_DBL(0.5f) - (FIXP_DBL)1)) || (accu <= FL2FXCONST_DBL(-0.5f)) ) 150 *ptrSum_e += 1; 151 else 152 accu = (shiftedMantissa + otherMantissa); 153 154 *ptrSum_m = FX_DBL2FX_SGL(accu); 155 156} 157 158inline void FDK_add_MantExp(FIXP_DBL a, /*!< Mantissa of 1st operand a */ 159 SCHAR a_e, /*!< Exponent of 1st operand a */ 160 FIXP_DBL b, /*!< Mantissa of 2nd operand b */ 161 SCHAR b_e, /*!< Exponent of 2nd operand b */ 162 FIXP_DBL *ptrSum, /*!< Mantissa of result */ 163 SCHAR *ptrSum_e) /*!< Exponent of result */ 164{ 165 FIXP_DBL accu; 166 int shift; 167 int shiftAbs; 168 169 FIXP_DBL shiftedMantissa; 170 FIXP_DBL otherMantissa; 171 172 /* Equalize exponents of the summands. 173 For the smaller summand, the exponent is adapted and 174 for compensation, the mantissa is shifted right. */ 175 176 shift = (int)(a_e - b_e); 177 178 shiftAbs = (shift>0)? shift : -shift; 179 shiftAbs = (shiftAbs < DFRACT_BITS-1)? shiftAbs : DFRACT_BITS-1; 180 shiftedMantissa = (shift>0)? (b >> shiftAbs) : (a >> shiftAbs); 181 otherMantissa = (shift>0)? a : b; 182 *ptrSum_e = (shift>0)? a_e : b_e; 183 184 accu = (shiftedMantissa >> 1) + (otherMantissa >> 1); 185 /* shift by 1 bit to avoid overflow */ 186 187 if ( (accu >= (FL2FXCONST_DBL(0.5f) - (FIXP_DBL)1)) || (accu <= FL2FXCONST_DBL(-0.5f)) ) 188 *ptrSum_e += 1; 189 else 190 accu = (shiftedMantissa + otherMantissa); 191 192 *ptrSum = accu; 193 194} 195 196/************************************************************************/ 197/*! 198 \brief Divide two values given by mantissa and exponent. 199 200 Mantissas are in fract format with values between 0 and 1. <br> 201 The base for exponents is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> 202 203 For performance reasons, the division is based on a table lookup 204 which limits accuracy. 205*/ 206/************************************************************************/ 207static inline void FDK_divide_MantExp(FIXP_SGL a_m, /*!< Mantissa of dividend a */ 208 SCHAR a_e, /*!< Exponent of dividend a */ 209 FIXP_SGL b_m, /*!< Mantissa of divisor b */ 210 SCHAR b_e, /*!< Exponent of divisor b */ 211 FIXP_SGL *ptrResult_m, /*!< Mantissa of quotient a/b */ 212 SCHAR *ptrResult_e) /*!< Exponent of quotient a/b */ 213 214{ 215 int preShift, postShift, index, shift; 216 FIXP_DBL ratio_m; 217 FIXP_SGL bInv_m = FL2FXCONST_SGL(0.0f); 218 219 preShift = CntLeadingZeros(FX_SGL2FX_DBL(b_m)); 220 221 /* 222 Shift b into the range from 0..INV_TABLE_SIZE-1, 223 224 E.g. 10 bits must be skipped for INV_TABLE_BITS 8: 225 - leave 8 bits as index for table 226 - skip sign bit, 227 - skip first bit of mantissa, because this is always the same (>0.5) 228 229 We are dealing with energies, so we need not care 230 about negative numbers 231 */ 232 233 /* 234 The first interval has half width so the lowest bit of the index is 235 needed for a doubled resolution. 236 */ 237 shift = (FRACT_BITS - 2 - INV_TABLE_BITS - preShift); 238 239 index = (shift<0)? (LONG)b_m << (-shift) : (LONG)b_m >> shift; 240 241 242 /* The index has INV_TABLE_BITS +1 valid bits here. Clear the other bits. */ 243 index &= (1 << (INV_TABLE_BITS+1)) - 1; 244 245 /* Remove offset of half an interval */ 246 index--; 247 248 /* Now the lowest bit is shifted out */ 249 index = index >> 1; 250 251 /* Fetch inversed mantissa from table: */ 252 bInv_m = (index<0)? bInv_m : FDK_sbrDecoder_invTable[index]; 253 254 /* Multiply a with the inverse of b: */ 255 ratio_m = (index<0)? FX_SGL2FX_DBL(a_m >> 1) : fMultDiv2(bInv_m,a_m); 256 257 postShift = CntLeadingZeros(ratio_m)-1; 258 259 *ptrResult_m = FX_DBL2FX_SGL(ratio_m << postShift); 260 *ptrResult_e = a_e - b_e + 1 + preShift - postShift; 261} 262 263static inline void FDK_divide_MantExp(FIXP_DBL a_m, /*!< Mantissa of dividend a */ 264 SCHAR a_e, /*!< Exponent of dividend a */ 265 FIXP_DBL b_m, /*!< Mantissa of divisor b */ 266 SCHAR b_e, /*!< Exponent of divisor b */ 267 FIXP_DBL *ptrResult_m, /*!< Mantissa of quotient a/b */ 268 SCHAR *ptrResult_e) /*!< Exponent of quotient a/b */ 269 270{ 271 int preShift, postShift, index, shift; 272 FIXP_DBL ratio_m; 273 FIXP_SGL bInv_m = FL2FXCONST_SGL(0.0f); 274 275 preShift = CntLeadingZeros(b_m); 276 277 /* 278 Shift b into the range from 0..INV_TABLE_SIZE-1, 279 280 E.g. 10 bits must be skipped for INV_TABLE_BITS 8: 281 - leave 8 bits as index for table 282 - skip sign bit, 283 - skip first bit of mantissa, because this is always the same (>0.5) 284 285 We are dealing with energies, so we need not care 286 about negative numbers 287 */ 288 289 /* 290 The first interval has half width so the lowest bit of the index is 291 needed for a doubled resolution. 292 */ 293 shift = (DFRACT_BITS - 2 - INV_TABLE_BITS - preShift); 294 295 index = (shift<0)? (LONG)b_m << (-shift) : (LONG)b_m >> shift; 296 297 298 /* The index has INV_TABLE_BITS +1 valid bits here. Clear the other bits. */ 299 index &= (1 << (INV_TABLE_BITS+1)) - 1; 300 301 /* Remove offset of half an interval */ 302 index--; 303 304 /* Now the lowest bit is shifted out */ 305 index = index >> 1; 306 307 /* Fetch inversed mantissa from table: */ 308 bInv_m = (index<0)? bInv_m : FDK_sbrDecoder_invTable[index]; 309 310 /* Multiply a with the inverse of b: */ 311 ratio_m = (index<0)? (a_m >> 1) : fMultDiv2(bInv_m,a_m); 312 313 postShift = CntLeadingZeros(ratio_m)-1; 314 315 *ptrResult_m = ratio_m << postShift; 316 *ptrResult_e = a_e - b_e + 1 + preShift - postShift; 317} 318 319/*! 320 \brief Calculate the squareroot of a number given by mantissa and exponent 321 322 Mantissa is in fract format with values between 0 and 1. <br> 323 The base for the exponent is 2. Example: \f$ a = a\_m * 2^{a\_e} \f$<br> 324 The operand is addressed via pointers and will be overwritten with the result. 325 326 For performance reasons, the square root is based on a table lookup 327 which limits accuracy. 328*/ 329static inline void FDK_sqrt_MantExp(FIXP_DBL *mantissa, /*!< Pointer to mantissa */ 330 SCHAR *exponent, 331 const SCHAR *destScale) 332{ 333 FIXP_DBL input_m = *mantissa; 334 int input_e = (int) *exponent; 335 FIXP_DBL result = FL2FXCONST_DBL(0.0f); 336 int result_e = -FRACT_BITS; 337 338 /* Call lookup square root, which does internally normalization. */ 339 result = sqrtFixp_lookup(input_m, &input_e); 340 result_e = input_e; 341 342 /* Write result */ 343 if (exponent==destScale) { 344 *mantissa = result; 345 *exponent = result_e; 346 } else { 347 int shift = result_e - *destScale; 348 *mantissa = (shift>=0) ? result << (INT)fixMin(DFRACT_BITS-1,shift) 349 : result >> (INT)fixMin(DFRACT_BITS-1,-shift); 350 *exponent = *destScale; 351 } 352} 353 354 355#endif 356