1/* ----------------------------------------------------------------------------- 2Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten 5Forschung e.V. All rights reserved. 6 7 1. INTRODUCTION 8The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software 9that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding 10scheme for digital audio. This FDK AAC Codec software is intended to be used on 11a wide variety of Android devices. 12 13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient 14general perceptual audio codecs. AAC-ELD is considered the best-performing 15full-bandwidth communications codec by independent studies and is widely 16deployed. AAC has been standardized by ISO and IEC as part of the MPEG 17specifications. 18 19Patent licenses for necessary patent claims for the FDK AAC Codec (including 20those of Fraunhofer) may be obtained through Via Licensing 21(www.vialicensing.com) or through the respective patent owners individually for 22the purpose of encoding or decoding bit streams in products that are compliant 23with the ISO/IEC MPEG audio standards. Please note that most manufacturers of 24Android devices already license these patent claims through Via Licensing or 25directly from the patent owners, and therefore FDK AAC Codec software may 26already be covered under those patent licenses when it is used for those 27licensed purposes only. 28 29Commercially-licensed AAC software libraries, including floating-point versions 30with enhanced sound quality, are also available from Fraunhofer. Users are 31encouraged to check the Fraunhofer website for additional applications 32information and documentation. 33 342. COPYRIGHT LICENSE 35 36Redistribution and use in source and binary forms, with or without modification, 37are permitted without payment of copyright license fees provided that you 38satisfy the following conditions: 39 40You must retain the complete text of this software license in redistributions of 41the FDK AAC Codec or your modifications thereto in source code form. 42 43You must retain the complete text of this software license in the documentation 44and/or other materials provided with redistributions of the FDK AAC Codec or 45your modifications thereto in binary form. You must make available free of 46charge copies of the complete source code of the FDK AAC Codec and your 47modifications thereto to recipients of copies in binary form. 48 49The name of Fraunhofer may not be used to endorse or promote products derived 50from this library without prior written permission. 51 52You may not charge copyright license fees for anyone to use, copy or distribute 53the FDK AAC Codec software or your modifications thereto. 54 55Your modified versions of the FDK AAC Codec must carry prominent notices stating 56that you changed the software and the date of any change. For modified versions 57of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android" 58must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK 59AAC Codec Library for Android." 60 613. NO PATENT LICENSE 62 63NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without 64limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. 65Fraunhofer provides no warranty of patent non-infringement with respect to this 66software. 67 68You may use this FDK AAC Codec software or modifications thereto only for 69purposes that are authorized by appropriate patent licenses. 70 714. DISCLAIMER 72 73This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright 74holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, 75including but not limited to the implied warranties of merchantability and 76fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 77CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, 78or consequential damages, including but not limited to procurement of substitute 79goods or services; loss of use, data, or profits, or business interruption, 80however caused and on any theory of liability, whether in contract, strict 81liability, or tort (including negligence), arising in any way out of the use of 82this software, even if advised of the possibility of such damage. 83 845. CONTACT INFORMATION 85 86Fraunhofer Institute for Integrated Circuits IIS 87Attention: Audio and Multimedia Departments - FDK AAC LL 88Am Wolfsmantel 33 8991058 Erlangen, Germany 90 91www.iis.fraunhofer.de/amm 92amm-info@iis.fraunhofer.de 93----------------------------------------------------------------------------- */ 94 95/**************************** AAC encoder library ****************************** 96 97 Author(s): M. Werner 98 99 Description: Band/Line energy calculations 100 101*******************************************************************************/ 102 103#include "band_nrg.h" 104 105/***************************************************************************** 106 functionname: FDKaacEnc_CalcSfbMaxScaleSpec 107 description: 108 input: 109 output: 110*****************************************************************************/ 111void FDKaacEnc_CalcSfbMaxScaleSpec(const FIXP_DBL *RESTRICT mdctSpectrum, 112 const INT *RESTRICT bandOffset, 113 INT *RESTRICT sfbMaxScaleSpec, 114 const INT numBands) { 115 INT i, j; 116 FIXP_DBL maxSpc, tmp; 117 118 for (i = 0; i < numBands; i++) { 119 maxSpc = (FIXP_DBL)0; 120 121 DWORD_ALIGNED(mdctSpectrum); 122 123 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 124 tmp = fixp_abs(mdctSpectrum[j]); 125 maxSpc = fixMax(maxSpc, tmp); 126 } 127 j = CntLeadingZeros(maxSpc) - 1; 128 sfbMaxScaleSpec[i] = fixMin((DFRACT_BITS - 2), j); 129 /* CountLeadingBits() is not necessary here since test value is always > 0 130 */ 131 } 132} 133 134/***************************************************************************** 135 functionname: FDKaacEnc_CheckBandEnergyOptim 136 description: 137 input: 138 output: 139*****************************************************************************/ 140FIXP_DBL 141FDKaacEnc_CheckBandEnergyOptim(const FIXP_DBL *const RESTRICT mdctSpectrum, 142 const INT *const RESTRICT sfbMaxScaleSpec, 143 const INT *const RESTRICT bandOffset, 144 const INT numBands, 145 FIXP_DBL *RESTRICT bandEnergy, 146 FIXP_DBL *RESTRICT bandEnergyLdData, 147 const INT minSpecShift) { 148 INT i, j, scale, nr = 0; 149 FIXP_DBL maxNrgLd = FL2FXCONST_DBL(-1.0f); 150 FIXP_DBL maxNrg = 0; 151 FIXP_DBL spec; 152 153 for (i = 0; i < numBands; i++) { 154 scale = fixMax(0, sfbMaxScaleSpec[i] - 4); 155 FIXP_DBL tmp = 0; 156 157 DWORD_ALIGNED(mdctSpectrum); 158 159 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 160 spec = mdctSpectrum[j] << scale; 161 tmp = fPow2AddDiv2(tmp, spec); 162 } 163 bandEnergy[i] = tmp << 1; 164 165 /* calculate ld of bandNrg, subtract scaling */ 166 bandEnergyLdData[i] = CalcLdData(bandEnergy[i]); 167 if (bandEnergyLdData[i] != FL2FXCONST_DBL(-1.0f)) { 168 bandEnergyLdData[i] -= scale * FL2FXCONST_DBL(2.0 / 64); 169 } 170 /* find index of maxNrg */ 171 if (bandEnergyLdData[i] > maxNrgLd) { 172 maxNrgLd = bandEnergyLdData[i]; 173 nr = i; 174 } 175 } 176 177 /* return unscaled maxNrg*/ 178 scale = fixMax(0, sfbMaxScaleSpec[nr] - 4); 179 scale = fixMax(2 * (minSpecShift - scale), -(DFRACT_BITS - 1)); 180 181 maxNrg = scaleValue(bandEnergy[nr], scale); 182 183 return maxNrg; 184} 185 186/***************************************************************************** 187 functionname: FDKaacEnc_CalcBandEnergyOptimLong 188 description: 189 input: 190 output: 191*****************************************************************************/ 192INT FDKaacEnc_CalcBandEnergyOptimLong(const FIXP_DBL *RESTRICT mdctSpectrum, 193 INT *RESTRICT sfbMaxScaleSpec, 194 const INT *RESTRICT bandOffset, 195 const INT numBands, 196 FIXP_DBL *RESTRICT bandEnergy, 197 FIXP_DBL *RESTRICT bandEnergyLdData) { 198 INT i, j, shiftBits = 0; 199 FIXP_DBL maxNrgLd = FL2FXCONST_DBL(0.0f); 200 201 FIXP_DBL spec; 202 203 for (i = 0; i < numBands; i++) { 204 INT leadingBits = sfbMaxScaleSpec[i] - 205 4; /* max sfbWidth = 96 ; 2^7=128 => 7/2 = 4 (spc*spc) */ 206 FIXP_DBL tmp = FL2FXCONST_DBL(0.0); 207 /* don't use scaleValue() here, it increases workload quite sufficiently... 208 */ 209 if (leadingBits >= 0) { 210 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 211 spec = mdctSpectrum[j] << leadingBits; 212 tmp = fPow2AddDiv2(tmp, spec); 213 } 214 } else { 215 INT shift = -leadingBits; 216 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 217 spec = mdctSpectrum[j] >> shift; 218 tmp = fPow2AddDiv2(tmp, spec); 219 } 220 } 221 bandEnergy[i] = tmp << 1; 222 } 223 224 /* calculate ld of bandNrg, subtract scaling */ 225 LdDataVector(bandEnergy, bandEnergyLdData, numBands); 226 for (i = numBands; i-- != 0;) { 227 FIXP_DBL scaleDiff = (sfbMaxScaleSpec[i] - 4) * FL2FXCONST_DBL(2.0 / 64); 228 229 bandEnergyLdData[i] = (bandEnergyLdData[i] >= 230 ((FL2FXCONST_DBL(-1.f) >> 1) + (scaleDiff >> 1))) 231 ? bandEnergyLdData[i] - scaleDiff 232 : FL2FXCONST_DBL(-1.f); 233 /* find maxNrgLd */ 234 maxNrgLd = fixMax(maxNrgLd, bandEnergyLdData[i]); 235 } 236 237 if (maxNrgLd <= (FIXP_DBL)0) { 238 for (i = numBands; i-- != 0;) { 239 INT scale = fixMin((sfbMaxScaleSpec[i] - 4) << 1, (DFRACT_BITS - 1)); 240 bandEnergy[i] = scaleValue(bandEnergy[i], -scale); 241 } 242 return 0; 243 } else { /* scale down NRGs */ 244 while (maxNrgLd > FL2FXCONST_DBL(0.0f)) { 245 maxNrgLd -= FL2FXCONST_DBL(2.0 / 64); 246 shiftBits++; 247 } 248 for (i = numBands; i-- != 0;) { 249 INT scale = fixMin(((sfbMaxScaleSpec[i] - 4) + shiftBits) << 1, 250 (DFRACT_BITS - 1)); 251 bandEnergyLdData[i] -= shiftBits * FL2FXCONST_DBL(2.0 / 64); 252 bandEnergy[i] = scaleValue(bandEnergy[i], -scale); 253 } 254 return shiftBits; 255 } 256} 257 258/***************************************************************************** 259 functionname: FDKaacEnc_CalcBandEnergyOptimShort 260 description: 261 input: 262 output: 263*****************************************************************************/ 264void FDKaacEnc_CalcBandEnergyOptimShort(const FIXP_DBL *RESTRICT mdctSpectrum, 265 INT *RESTRICT sfbMaxScaleSpec, 266 const INT *RESTRICT bandOffset, 267 const INT numBands, 268 FIXP_DBL *RESTRICT bandEnergy) { 269 INT i, j; 270 271 for (i = 0; i < numBands; i++) { 272 int leadingBits = sfbMaxScaleSpec[i] - 273 3; /* max sfbWidth = 36 ; 2^6=64 => 6/2 = 3 (spc*spc) */ 274 FIXP_DBL tmp = FL2FXCONST_DBL(0.0); 275 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 276 FIXP_DBL spec = scaleValue(mdctSpectrum[j], leadingBits); 277 tmp = fPow2AddDiv2(tmp, spec); 278 } 279 bandEnergy[i] = tmp; 280 } 281 282 for (i = 0; i < numBands; i++) { 283 INT scale = (2 * (sfbMaxScaleSpec[i] - 3)) - 284 1; /* max sfbWidth = 36 ; 2^6=64 => 6/2 = 3 (spc*spc) */ 285 scale = fixMax(fixMin(scale, (DFRACT_BITS - 1)), -(DFRACT_BITS - 1)); 286 bandEnergy[i] = scaleValueSaturate(bandEnergy[i], -scale); 287 } 288} 289 290/***************************************************************************** 291 functionname: FDKaacEnc_CalcBandNrgMSOpt 292 description: 293 input: 294 output: 295*****************************************************************************/ 296void FDKaacEnc_CalcBandNrgMSOpt( 297 const FIXP_DBL *RESTRICT mdctSpectrumLeft, 298 const FIXP_DBL *RESTRICT mdctSpectrumRight, 299 INT *RESTRICT sfbMaxScaleSpecLeft, INT *RESTRICT sfbMaxScaleSpecRight, 300 const INT *RESTRICT bandOffset, const INT numBands, 301 FIXP_DBL *RESTRICT bandEnergyMid, FIXP_DBL *RESTRICT bandEnergySide, 302 INT calcLdData, FIXP_DBL *RESTRICT bandEnergyMidLdData, 303 FIXP_DBL *RESTRICT bandEnergySideLdData) { 304 INT i, j, minScale; 305 FIXP_DBL NrgMid, NrgSide, specm, specs; 306 307 for (i = 0; i < numBands; i++) { 308 NrgMid = NrgSide = FL2FXCONST_DBL(0.0); 309 minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]) - 4; 310 minScale = fixMax(0, minScale); 311 312 if (minScale > 0) { 313 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 314 FIXP_DBL specL = mdctSpectrumLeft[j] << (minScale - 1); 315 FIXP_DBL specR = mdctSpectrumRight[j] << (minScale - 1); 316 specm = specL + specR; 317 specs = specL - specR; 318 NrgMid = fPow2AddDiv2(NrgMid, specm); 319 NrgSide = fPow2AddDiv2(NrgSide, specs); 320 } 321 } else { 322 for (j = bandOffset[i]; j < bandOffset[i + 1]; j++) { 323 FIXP_DBL specL = mdctSpectrumLeft[j] >> 1; 324 FIXP_DBL specR = mdctSpectrumRight[j] >> 1; 325 specm = specL + specR; 326 specs = specL - specR; 327 NrgMid = fPow2AddDiv2(NrgMid, specm); 328 NrgSide = fPow2AddDiv2(NrgSide, specs); 329 } 330 } 331 bandEnergyMid[i] = fMin(NrgMid, (FIXP_DBL)MAXVAL_DBL >> 1) << 1; 332 bandEnergySide[i] = fMin(NrgSide, (FIXP_DBL)MAXVAL_DBL >> 1) << 1; 333 } 334 335 if (calcLdData) { 336 LdDataVector(bandEnergyMid, bandEnergyMidLdData, numBands); 337 LdDataVector(bandEnergySide, bandEnergySideLdData, numBands); 338 } 339 340 for (i = 0; i < numBands; i++) { 341 minScale = fixMin(sfbMaxScaleSpecLeft[i], sfbMaxScaleSpecRight[i]); 342 INT scale = fixMax(0, 2 * (minScale - 4)); 343 344 if (calcLdData) { 345 /* using the minimal scaling of left and right channel can cause very 346 small energies; check ldNrg before subtract scaling multiplication: 347 fract*INT we don't need fMult */ 348 349 int minus = scale * FL2FXCONST_DBL(1.0 / 64); 350 351 if (bandEnergyMidLdData[i] != FL2FXCONST_DBL(-1.0f)) 352 bandEnergyMidLdData[i] -= minus; 353 354 if (bandEnergySideLdData[i] != FL2FXCONST_DBL(-1.0f)) 355 bandEnergySideLdData[i] -= minus; 356 } 357 scale = fixMin(scale, (DFRACT_BITS - 1)); 358 bandEnergyMid[i] >>= scale; 359 bandEnergySide[i] >>= scale; 360 } 361} 362