1 /* ----------------------------------------------------------------------------- 2 Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4 Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Frderung 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 (at) iis.fraunhofer.de 93 ----------------------------------------------------------------------------- */ 94 95 /******************* MPEG transport format decoder library ********************* 96 97 Author(s): Josef Hoepfl 98 99 Description: ADTS interface 100 101 *******************************************************************************/ 102 103 #include "tpdec_adts.h" 104 105 #include "FDK_bitstream.h" 106 107 void adtsRead_CrcInit( 108 HANDLE_ADTS pAdts) /*!< pointer to adts crc info stucture */ 109 { 110 FDKcrcInit(&pAdts->crcInfo, 0x8005, 0xFFFF, 16); 111 } 112 113 int adtsRead_CrcStartReg( 114 HANDLE_ADTS pAdts, /*!< pointer to adts stucture */ 115 HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */ 116 int mBits /*!< number of bits in crc region */ 117 ) { 118 if (pAdts->bs.protection_absent) { 119 return 0; 120 } 121 122 return (FDKcrcStartReg(&pAdts->crcInfo, hBs, mBits)); 123 } 124 125 void adtsRead_CrcEndReg( 126 HANDLE_ADTS pAdts, /*!< pointer to adts crc info stucture */ 127 HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */ 128 int reg /*!< crc region */ 129 ) { 130 if (pAdts->bs.protection_absent == 0) { 131 FDKcrcEndReg(&pAdts->crcInfo, hBs, reg); 132 } 133 } 134 135 TRANSPORTDEC_ERROR adtsRead_CrcCheck(HANDLE_ADTS pAdts) { 136 TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK; 137 USHORT crc; 138 139 if (pAdts->bs.protection_absent) return TRANSPORTDEC_OK; 140 141 crc = FDKcrcGetCRC(&pAdts->crcInfo); 142 if (crc != pAdts->crcReadValue) { 143 return (TRANSPORTDEC_CRC_ERROR); 144 } 145 146 return (ErrorStatus); 147 } 148 149 #define Adts_Length_SyncWord 12 150 #define Adts_Length_Id 1 151 #define Adts_Length_Layer 2 152 #define Adts_Length_ProtectionAbsent 1 153 #define Adts_Length_Profile 2 154 #define Adts_Length_SamplingFrequencyIndex 4 155 #define Adts_Length_PrivateBit 1 156 #define Adts_Length_ChannelConfiguration 3 157 #define Adts_Length_OriginalCopy 1 158 #define Adts_Length_Home 1 159 #define Adts_Length_CopyrightIdentificationBit 1 160 #define Adts_Length_CopyrightIdentificationStart 1 161 #define Adts_Length_FrameLength 13 162 #define Adts_Length_BufferFullness 11 163 #define Adts_Length_NumberOfRawDataBlocksInFrame 2 164 #define Adts_Length_CrcCheck 16 165 166 TRANSPORTDEC_ERROR adtsRead_DecodeHeader(HANDLE_ADTS pAdts, 167 CSAudioSpecificConfig *pAsc, 168 HANDLE_FDK_BITSTREAM hBs, 169 const INT ignoreBufferFullness) { 170 INT crcReg; 171 172 INT valBits; 173 INT cmp_buffer_fullness; 174 int i, adtsHeaderLength; 175 176 STRUCT_ADTS_BS bs; 177 178 CProgramConfig oldPce; 179 /* Store the old PCE temporarily. Maybe we'll need it later if we 180 have channelConfig=0 and no PCE in this frame. */ 181 FDKmemcpy(&oldPce, &pAsc->m_progrConfigElement, sizeof(CProgramConfig)); 182 183 valBits = FDKgetValidBits(hBs); 184 185 /* adts_fixed_header */ 186 bs.mpeg_id = FDKreadBits(hBs, Adts_Length_Id); 187 bs.layer = FDKreadBits(hBs, Adts_Length_Layer); 188 bs.protection_absent = FDKreadBits(hBs, Adts_Length_ProtectionAbsent); 189 bs.profile = FDKreadBits(hBs, Adts_Length_Profile); 190 bs.sample_freq_index = FDKreadBits(hBs, Adts_Length_SamplingFrequencyIndex); 191 bs.private_bit = FDKreadBits(hBs, Adts_Length_PrivateBit); 192 bs.channel_config = FDKreadBits(hBs, Adts_Length_ChannelConfiguration); 193 bs.original = FDKreadBits(hBs, Adts_Length_OriginalCopy); 194 bs.home = FDKreadBits(hBs, Adts_Length_Home); 195 196 /* adts_variable_header */ 197 bs.copyright_id = FDKreadBits(hBs, Adts_Length_CopyrightIdentificationBit); 198 bs.copyright_start = 199 FDKreadBits(hBs, Adts_Length_CopyrightIdentificationStart); 200 bs.frame_length = FDKreadBits(hBs, Adts_Length_FrameLength); 201 bs.adts_fullness = FDKreadBits(hBs, Adts_Length_BufferFullness); 202 bs.num_raw_blocks = 203 FDKreadBits(hBs, Adts_Length_NumberOfRawDataBlocksInFrame); 204 bs.num_pce_bits = 0; 205 206 adtsHeaderLength = ADTS_HEADERLENGTH; 207 208 if (!bs.protection_absent) { 209 FDKcrcReset(&pAdts->crcInfo); 210 FDKpushBack(hBs, 56); /* complete fixed and variable header! */ 211 crcReg = FDKcrcStartReg(&pAdts->crcInfo, hBs, 0); 212 FDKpushFor(hBs, 56); 213 } 214 215 if (!bs.protection_absent && bs.num_raw_blocks > 0) { 216 for (i = 0; i < bs.num_raw_blocks; i++) { 217 pAdts->rawDataBlockDist[i] = (USHORT)FDKreadBits(hBs, 16); 218 adtsHeaderLength += 16; 219 } 220 /* Change raw data blocks to delta values */ 221 pAdts->rawDataBlockDist[bs.num_raw_blocks] = 222 bs.frame_length - 7 - bs.num_raw_blocks * 2 - 2; 223 for (i = bs.num_raw_blocks; i > 0; i--) { 224 pAdts->rawDataBlockDist[i] -= pAdts->rawDataBlockDist[i - 1]; 225 } 226 } 227 228 /* adts_error_check */ 229 if (!bs.protection_absent) { 230 USHORT crc_check; 231 232 FDKcrcEndReg(&pAdts->crcInfo, hBs, crcReg); 233 crc_check = FDKreadBits(hBs, Adts_Length_CrcCheck); 234 adtsHeaderLength += Adts_Length_CrcCheck; 235 236 pAdts->crcReadValue = crc_check; 237 /* Check header CRC in case of multiple raw data blocks */ 238 if (bs.num_raw_blocks > 0) { 239 if (pAdts->crcReadValue != FDKcrcGetCRC(&pAdts->crcInfo)) { 240 return TRANSPORTDEC_CRC_ERROR; 241 } 242 /* Reset CRC for the upcoming raw_data_block() */ 243 FDKcrcReset(&pAdts->crcInfo); 244 } 245 } 246 247 /* check if valid header */ 248 if ((bs.layer != 0) || // we only support MPEG ADTS 249 (bs.sample_freq_index >= 13) // we only support 96kHz - 7350kHz 250 ) { 251 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later 252 return TRANSPORTDEC_UNSUPPORTED_FORMAT; 253 } 254 255 /* special treatment of id-bit */ 256 if ((bs.mpeg_id == 0) && (pAdts->decoderCanDoMpeg4 == 0)) { 257 /* MPEG-2 decoder cannot play MPEG-4 bitstreams */ 258 259 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later 260 return TRANSPORTDEC_UNSUPPORTED_FORMAT; 261 } 262 263 if (!ignoreBufferFullness) { 264 cmp_buffer_fullness = 265 bs.frame_length * 8 + 266 bs.adts_fullness * 32 * getNumberOfEffectiveChannels(bs.channel_config); 267 268 /* Evaluate buffer fullness */ 269 if (bs.adts_fullness != 0x7FF) { 270 if (pAdts->BufferFullnesStartFlag) { 271 if (valBits < cmp_buffer_fullness) { 272 /* Condition for start of decoding is not fulfilled */ 273 274 /* The current frame will not be decoded */ 275 FDKpushBack(hBs, adtsHeaderLength); 276 277 if ((cmp_buffer_fullness + adtsHeaderLength) > 278 (((8192 * 4) << 3) - 7)) { 279 return TRANSPORTDEC_SYNC_ERROR; 280 } else { 281 return TRANSPORTDEC_NOT_ENOUGH_BITS; 282 } 283 } else { 284 pAdts->BufferFullnesStartFlag = 0; 285 } 286 } 287 } 288 } 289 290 /* Get info from ADTS header */ 291 AudioSpecificConfig_Init(pAsc); 292 pAsc->m_aot = (AUDIO_OBJECT_TYPE)(bs.profile + 1); 293 pAsc->m_samplingFrequencyIndex = bs.sample_freq_index; 294 pAsc->m_samplingFrequency = SamplingRateTable[bs.sample_freq_index]; 295 pAsc->m_channelConfiguration = bs.channel_config; 296 pAsc->m_samplesPerFrame = 1024; 297 298 if (bs.channel_config == 0) { 299 int pceBits = 0; 300 UINT alignAnchor = FDKgetValidBits(hBs); 301 302 if (FDKreadBits(hBs, 3) == ID_PCE) { 303 /* Got luck! Parse the PCE */ 304 crcReg = adtsRead_CrcStartReg(pAdts, hBs, 0); 305 306 CProgramConfig_Read(&pAsc->m_progrConfigElement, hBs, alignAnchor); 307 308 adtsRead_CrcEndReg(pAdts, hBs, crcReg); 309 pceBits = alignAnchor - FDKgetValidBits(hBs); 310 /* store the number of PCE bits */ 311 bs.num_pce_bits = pceBits; 312 } else { 313 /* No PCE in this frame! Push back the ID tag bits. */ 314 FDKpushBack(hBs, 3); 315 316 /* Encoders do not have to write a PCE in each frame. 317 So if we already have a valid PCE we have to use it. */ 318 if (oldPce.isValid && 319 (bs.sample_freq_index == 320 pAdts->bs.sample_freq_index) /* we could compare the complete fixed 321 header (bytes) here! */ 322 && (bs.channel_config == pAdts->bs.channel_config) /* == 0 */ 323 && 324 (bs.mpeg_id == 325 pAdts->bs.mpeg_id)) { /* Restore previous PCE which is still valid */ 326 FDKmemcpy(&pAsc->m_progrConfigElement, &oldPce, sizeof(CProgramConfig)); 327 } else if (bs.mpeg_id == 0) { 328 /* If not it seems that we have a implicit channel configuration. 329 This mode is not allowed in the context of ISO/IEC 14496-3. 330 Skip this frame and try the next one. */ 331 FDKpushFor(hBs, (bs.frame_length << 3) - adtsHeaderLength - 3); 332 return TRANSPORTDEC_UNSUPPORTED_FORMAT; 333 } 334 /* else { 335 ISO/IEC 13818-7 implicit channel mapping is allowed. 336 So just open the box of chocolates to see what we got. 337 } */ 338 } 339 } 340 341 /* Copy bit stream data struct to persistent memory now, once we passed all 342 * sanity checks above. */ 343 FDKmemcpy(&pAdts->bs, &bs, sizeof(STRUCT_ADTS_BS)); 344 345 return TRANSPORTDEC_OK; 346 } 347 348 int adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts, INT blockNum) { 349 int length; 350 351 if (pAdts->bs.num_raw_blocks == 0) { 352 length = 353 (pAdts->bs.frame_length - 7) 354 << 3; /* aac_frame_length subtracted by the header size (7 bytes). */ 355 if (pAdts->bs.protection_absent == 0) 356 length -= 16; /* substract 16 bit CRC */ 357 } else { 358 if (pAdts->bs.protection_absent) { 359 length = -1; /* raw data block length is unknown */ 360 } else { 361 if (blockNum < 0 || blockNum > 3) { 362 length = -1; 363 } else { 364 length = (pAdts->rawDataBlockDist[blockNum] << 3) - 16; 365 } 366 } 367 } 368 if (blockNum == 0 && length > 0) { 369 length -= pAdts->bs.num_pce_bits; 370 } 371 return length; 372 } 373
