1 2 /* ----------------------------------------------------------------------------------------------------------- 3 Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5 Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Frderung der angewandten Forschung e.V. 6 All rights reserved. 7 8 1. INTRODUCTION 9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements 10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. 11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual 14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by 15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part 16 of the MPEG specifications. 17 18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) 19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners 20 individually for the purpose of encoding or decoding bit streams in products that are compliant with 21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license 22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec 23 software may already be covered under those patent licenses when it is used for those licensed purposes only. 24 25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, 26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional 27 applications information and documentation. 28 29 2. COPYRIGHT LICENSE 30 31 Redistribution and use in source and binary forms, with or without modification, are permitted without 32 payment of copyright license fees provided that you satisfy the following conditions: 33 34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or 35 your modifications thereto in source code form. 36 37 You must retain the complete text of this software license in the documentation and/or other materials 38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. 39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your 40 modifications thereto to recipients of copies in binary form. 41 42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without 43 prior written permission. 44 45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec 46 software or your modifications thereto. 47 48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software 49 and 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 53 3. NO PATENT LICENSE 54 55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, 56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with 57 respect to this software. 58 59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized 60 by appropriate patent licenses. 61 62 4. DISCLAIMER 63 64 This 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 66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, 68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits, 69 or business interruption, however caused and on any theory of liability, whether in contract, strict 70 liability, or tort (including negligence), arising in any way out of the use of this software, even if 71 advised of the possibility of such damage. 72 73 5. CONTACT INFORMATION 74 75 Fraunhofer Institute for Integrated Circuits IIS 76 Attention: Audio and Multimedia Departments - FDK AAC LL 77 Am Wolfsmantel 33 78 91058 Erlangen, Germany 79 80 www.iis.fraunhofer.de/amm 81 amm-info (at) iis.fraunhofer.de 82 ----------------------------------------------------------------------------------------------------------- */ 83 84 /***************************** MPEG-4 AAC Decoder ************************** 85 86 Author(s): Manuel Jander 87 88 ******************************************************************************/ 89 90 /** 91 * \file aacdecoder_lib.h 92 * \brief FDK AAC decoder library interface header file. 93 * 94 95 \page INTRO Introduction 96 97 \section SCOPE Scope 98 99 This document describes the high-level interface and usage of the ISO/MPEG-2/4 AAC Decoder 100 library developed by the Fraunhofer Institute for Integrated Circuits (IIS). 101 Depending on the library configuration, it implements decoding of AAC-LC (Low-Complexity), 102 HE-AAC (High-Efficiency AAC, v1 and v2), AAC-LD (Low-Delay) and AAC-ELD (Enhanced Low-Delay). 103 104 All references to SBR (Spectral Band Replication) are only applicable to HE-AAC and AAC-ELD 105 versions of the library. All references to PS (Parametric Stereo) are only applicable to 106 HE-AAC v2 versions of the library. 107 108 \section DecoderBasics Decoder Basics 109 110 This document can only give a rough overview about the ISO/MPEG-2 and ISO/MPEG-4 AAC audio 111 coding standard. To understand all the terms in this document, you are encouraged to read 112 the following documents. 113 114 - ISO/IEC 13818-7 (MPEG-2 AAC), which defines the syntax of MPEG-2 AAC audio bitstreams. 115 - ISO/IEC 14496-3 (MPEG-4 AAC, subpart 1 and 4), which defines the syntax of MPEG-4 AAC audio bitstreams. 116 - Lutzky, Schuller, Gayer, Krämer, Wabnik, "A guideline to audio codec delay", 116th AES Convention, May 8, 2004 117 118 MPEG Advanced Audio Coding is based on a time-to-frequency mapping of the signal. The signal 119 is partitioned into overlapping portions and transformed into frequency domain. The spectral 120 components are then quantized and coded.\n 121 An MPEG2 or MPEG4 AAC audio bitstream is composed of frames. Contrary to MPEG-1/2 Layer-3 (mp3), 122 the length of individual frames is not restricted to a fixed number of bytes, but can take on 123 any length between 1 and 768 bytes. 124 125 126 \page LIBUSE Library Usage 127 128 \section InterfaceDescritpion API Description 129 130 All API header files are located in the folder /include of the release package. They are described in 131 detail in this document. All header files are provided for usage in C/C++ programs. The AAC decoder library 132 API functions are located at aacdecoder_lib.h. 133 134 In binary releases the decoder core resides in statically linkable libraries called for example libAACdec.a, 135 (Linux) or FDK_aacDec_lib (Microsoft Visual C++). 136 137 \section Calling_Sequence Calling Sequence 138 139 For decoding of ISO/MPEG-2/4 AAC or HE-AAC v2 bitstreams the following sequence is mandatory. Input read 140 and output write functions as well as the corresponding open and close functions are left out, since they 141 may be implemented differently according to the user's specific requirements. The example implementation in 142 main.cpp uses file-based input/output, and in such case call mpegFileRead_Open() to open an input file and 143 to allocate memory for the required structures, and the corresponding mpegFileRead_Close() to close opened 144 files and to de-allocate associated structures. mpegFileRead_Open() tries to detect the bitstream format and 145 in case of MPEG-4 file format or Raw Packets file format (a Fraunhofer IIS proprietary format) reads the Audio 146 Specific Config data (ASC). An unsuccessful attempt to recognize the bitstream format requires the user to 147 provide this information manually. For any other bitstream formats that are usually applicable in streaming 148 applications, the decoder itself will try to synchronize and parse the given bitstream fragment using the 149 FDK transport library. Hence, for streaming applications (without file access) this step is not necessary. 150 151 -# Call aacDecoder_Open() to open and retrieve a handle to a new AAC decoder instance. 152 \dontinclude main.cpp 153 \skipline aacDecoder_Open 154 -# If out-of-band config data (Audio Specific Config (ASC) or Stream Mux Config (SMC)) is available, call 155 aacDecoder_ConfigRaw() to pass it to the decoder and before the decoding process starts. If this data is 156 not available in advance, the decoder will get it from the bitstream and configure itself while decoding 157 with aacDecoder_DecodeFrame(). 158 -# Begin decoding loop. 159 \skipline do { 160 -# Read data from bitstream file or stream into a client-supplied input buffer ("inBuffer" in main.cpp). 161 If it is very small like just 4, aacDecoder_DecodeFrame() will 162 repeatedly return ::AAC_DEC_NOT_ENOUGH_BITS until enough bits were fed by aacDecoder_Fill(). Only read data 163 when this buffer has completely been processed and is then empty. For file-based input execute 164 mpegFileRead_Read() or any other implementation with similar functionality. 165 -# Call aacDecoder_Fill() to fill the decoder's internal bitstream input buffer with the client-supplied 166 external bitstream input buffer. 167 \skipline aacDecoder_Fill 168 -# Call aacDecoder_DecodeFrame() which writes decoded PCM audio data to a client-supplied buffer. It is the 169 client's responsibility to allocate a buffer which is large enough to hold this output data. 170 \skipline aacDecoder_DecodeFrame 171 If the bitstream's configuration (number of channels, sample rate, frame size) is not known in advance, you may 172 call aacDecoder_GetStreamInfo() to retrieve a structure containing this information and then initialize an audio 173 output device. In the example main.cpp, if the number of channels or the sample rate has changed since program 174 start or since the previously decoded frame, the audio output device will be re-initialized. If WAVE file output 175 is chosen, a new WAVE file for each new configuration will be created. 176 \skipline aacDecoder_GetStreamInfo 177 -# Repeat steps 5 to 7 until no data to decode is available anymore, or if an error occured. 178 \skipline } while 179 -# Call aacDecoder_Close() to de-allocate all AAC decoder and transport layer structures. 180 \skipline aacDecoder_Close 181 182 \section BufferSystem Buffer System 183 184 There are three main buffers in an AAC decoder application. One external input buffer to hold bitstream 185 data from file I/O or elsewhere, one decoder-internal input buffer, and one to hold the decoded output 186 PCM sample data, whereas this output buffer may overlap with the external input buffer. 187 188 The external input buffer is set in the example framework main.cpp and its size is defined by ::IN_BUF_SIZE. 189 You may freely choose different sizes here. To feed the data to the decoder-internal input buffer, use the 190 function aacDecoder_Fill(). This function returns important information about how many bytes in the 191 external input buffer have not yet been copied into the internal input buffer (variable bytesValid). 192 Once the external buffer has been fully copied, it can be re-filled again. 193 In case you want to re-fill it when there are still unprocessed bytes (bytesValid is unequal 0), you 194 would have to additionally perform a memcpy(), so that just means unnecessary computational overhead 195 and therefore we recommend to re-fill the buffer only when bytesValid is 0. 196 197 \image latex dec_buffer.png "Lifecycle of the external input buffer" width=9cm 198 199 The size of the decoder-internal input buffer is set in tpdec_lib.h (see define ::TRANSPORTDEC_INBUF_SIZE). 200 You may choose a smaller size under the following considerations: 201 202 - each input channel requires 768 bytes 203 - the whole buffer must be of size 2^n 204 205 So for example a stereo decoder: 206 207 \f[ 208 TRANSPORTDEC\_INBUF\_SIZE = 2 * 768 = 1536 => 2048 209 \f] 210 211 tpdec_lib.h and TRANSPORTDEC_INBUF_SIZE are not part of the decoder's library interface. Therefore 212 only source-code clients may change this setting. If you received a library release, please ask us and 213 we can change this in order to meet your memory requirements. 214 215 \page OutputFormat Decoder audio output 216 217 \section OutputFormatObtaining Obtaining channel mapping information 218 219 The decoded audio output format is indicated by a set of variables of the CStreamInfo structure. 220 While the members sampleRate, frameSize and numChannels might be quite self explaining, 221 pChannelType and pChannelIndices might require some more detailed explanation. 222 223 These two arrays indicate what is each output channel supposed to be. Both array have 224 CStreamInfo::numChannels cells. Each cell of pChannelType indicates the channel type, described in 225 the enum ::AUDIO_CHANNEL_TYPE defined in FDK_audio.h. The cells of pChannelIndices indicate the sub index 226 among the channels starting with 0 among all channels of the same audio channel type. 227 228 The indexing scheme is the same as for MPEG-2/4. Thus indices are counted upwards starting from the front 229 direction (thus a center channel if any, will always be index 0). Then the indices count up, starting always 230 with the left side, pairwise from front toward back. For detailed explanation, please refer to 231 ISO/IEC 13818-7:2005(E), chapter 8.5.3.2. 232 233 In case a Program Config is included in the audio configuration, the channel mapping described within 234 it will be adopted. 235 236 In case of MPEG-D Surround the channel mapping will follow the same criteria described in ISO/IEC 13818-7:2005(E), 237 but adding corresponding top channels to the channel types front, side and back, in order to avoid any 238 loss of information. 239 240 \section OutputFormatChange Changing the audio output format 241 242 The channel interleaving scheme and the actual channel order can be changed at runtime through the 243 parameters ::AAC_PCM_OUTPUT_INTERLEAVED and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING. See the description of those 244 parameters and the decoder library function aacDecoder_SetParam() for more detail. 245 246 \section OutputFormatExample Channel mapping examples 247 248 The following examples illustrate the location of individual audio samples in the audio buffer that 249 is passed to aacDecoder_DecodeFrame() and the expected data in the CStreamInfo structure which can be obtained 250 by calling aacDecoder_GetStreamInfo(). 251 252 \subsection ExamplesStereo Stereo 253 254 In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 0 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1, 255 a AAC-LC bit stream which has channelConfiguration = 2 in its audio specific config would lead 256 to the following values in CStreamInfo: 257 258 CStreamInfo::numChannels = 2 259 260 CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT } 261 262 CStreamInfo::pChannelIndices = { 0, 1 } 263 264 Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 0, the audio channels will be located as contiguous blocks 265 in the output buffer as follows: 266 267 \verbatim 268 <left sample 0> <left sample 1> <left sample 2> ... <left sample N> 269 <right sample 0> <right sample 1> <right sample 2> ... <right sample N> 270 \endverbatim 271 272 Where N equals to CStreamInfo::frameSize . 273 274 \subsection ExamplesSurround Surround 5.1 275 276 In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1, 277 a AAC-LC bit stream which has channelConfiguration = 6 in its audio specific config, would lead 278 to the following values in CStreamInfo: 279 280 CStreamInfo::numChannels = 6 281 282 CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT, ::ACT_FRONT, ::ACT_LFE, ::ACT_BACK, ::ACT_BACK } 283 284 CStreamInfo::pChannelIndices = { 1, 2, 0, 0, 0, 1 } 285 286 Since ::AAC_PCM_OUTPUT_CHANNEL_MAPPING is 1, WAV file channel ordering will be used. For a 5.1 channel 287 scheme, thus the channels would be: front left, front right, center, LFE, surround left, surround right. 288 Thus the third channel is the center channel, receiving the index 0. The other front channels are 289 front left, front right being placed as first and second channels with indices 1 and 2 correspondingly. 290 There is only one LFE, placed as the fourth channel and index 0. Finally both surround 291 channels get the type definition ACT_BACK, and the indices 0 and 1. 292 293 Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 1, the audio channels will be placed in the output buffer 294 as follows: 295 296 \verbatim 297 <front left sample 0> <front right sample 0> 298 <center sample 0> <LFE sample 0> 299 <surround left sample 0> <surround right sample 0> 300 301 <front left sample 1> <front right sample 1> 302 <center sample 1> <LFE sample 1> 303 <surround left sample 1> <surround right sample 1> 304 305 ... 306 307 <front left sample N> <front right sample N> 308 <center sample N> <LFE sample N> 309 <surround left sample N> <surround right sample N> 310 \endverbatim 311 312 Where N equals to CStreamInfo::frameSize . 313 314 \subsection ExamplesArib ARIB coding mode 2/1 315 316 In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1, 317 in case of a ARIB bit stream using coding mode 2/1 as described in ARIB STD-B32 Part 2 Version 2.1-E1, page 61, 318 would lead to the following values in CStreamInfo: 319 320 CStreamInfo::numChannels = 3 321 322 CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT,:: ACT_BACK } 323 324 CStreamInfo::pChannelIndices = { 0, 1, 0 } 325 326 The audio channels will be placed as follows in the audio output buffer: 327 328 \verbatim 329 <front left sample 0> <front right sample 0> <mid surround sample 0> 330 331 <front left sample 1> <front right sample 1> <mid surround sample 1> 332 333 ... 334 335 <front left sample N> <front right sample N> <mid surround sample N> 336 337 Where N equals to CStreamInfo::frameSize . 338 339 \endverbatim 340 341 */ 342 343 #ifndef AACDECODER_LIB_H 344 #define AACDECODER_LIB_H 345 346 #include "machine_type.h" 347 #include "FDK_audio.h" 348 349 #include "genericStds.h" 350 351 /** 352 * \brief AAC decoder error codes. 353 */ 354 typedef enum { 355 AAC_DEC_OK = 0x0000, /*!< No error occured. Output buffer is valid and error free. */ 356 AAC_DEC_OUT_OF_MEMORY = 0x0002, /*!< Heap returned NULL pointer. Output buffer is invalid. */ 357 AAC_DEC_UNKNOWN = 0x0005, /*!< Error condition is of unknown reason, or from a another module. Output buffer is invalid. */ 358 359 /* Synchronization errors. Output buffer is invalid. */ 360 aac_dec_sync_error_start = 0x1000, 361 AAC_DEC_TRANSPORT_SYNC_ERROR = 0x1001, /*!< The transport decoder had syncronisation problems. Do not exit decoding. Just feed new 362 bitstream data. */ 363 AAC_DEC_NOT_ENOUGH_BITS = 0x1002, /*!< The input buffer ran out of bits. */ 364 aac_dec_sync_error_end = 0x1FFF, 365 366 /* Initialization errors. Output buffer is invalid. */ 367 aac_dec_init_error_start = 0x2000, 368 AAC_DEC_INVALID_HANDLE = 0x2001, /*!< The handle passed to the function call was invalid (NULL). */ 369 AAC_DEC_UNSUPPORTED_AOT = 0x2002, /*!< The AOT found in the configuration is not supported. */ 370 AAC_DEC_UNSUPPORTED_FORMAT = 0x2003, /*!< The bitstream format is not supported. */ 371 AAC_DEC_UNSUPPORTED_ER_FORMAT = 0x2004, /*!< The error resilience tool format is not supported. */ 372 AAC_DEC_UNSUPPORTED_EPCONFIG = 0x2005, /*!< The error protection format is not supported. */ 373 AAC_DEC_UNSUPPORTED_MULTILAYER = 0x2006, /*!< More than one layer for AAC scalable is not supported. */ 374 AAC_DEC_UNSUPPORTED_CHANNELCONFIG = 0x2007, /*!< The channel configuration (either number or arrangement) is not supported. */ 375 AAC_DEC_UNSUPPORTED_SAMPLINGRATE = 0x2008, /*!< The sample rate specified in the configuration is not supported. */ 376 AAC_DEC_INVALID_SBR_CONFIG = 0x2009, /*!< The SBR configuration is not supported. */ 377 AAC_DEC_SET_PARAM_FAIL = 0x200A, /*!< The parameter could not be set. Either the value was out of range or the parameter does 378 not exist. */ 379 AAC_DEC_NEED_TO_RESTART = 0x200B, /*!< The decoder needs to be restarted, since the requiered configuration change cannot be 380 performed. */ 381 aac_dec_init_error_end = 0x2FFF, 382 383 /* Decode errors. Output buffer is valid but concealed. */ 384 aac_dec_decode_error_start = 0x4000, 385 AAC_DEC_TRANSPORT_ERROR = 0x4001, /*!< The transport decoder encountered an unexpected error. */ 386 AAC_DEC_PARSE_ERROR = 0x4002, /*!< Error while parsing the bitstream. Most probably it is corrupted, or the system crashed. */ 387 AAC_DEC_UNSUPPORTED_EXTENSION_PAYLOAD = 0x4003, /*!< Error while parsing the extension payload of the bitstream. The extension payload type 388 found is not supported. */ 389 AAC_DEC_DECODE_FRAME_ERROR = 0x4004, /*!< The parsed bitstream value is out of range. Most probably the bitstream is corrupt, or 390 the system crashed. */ 391 AAC_DEC_CRC_ERROR = 0x4005, /*!< The embedded CRC did not match. */ 392 AAC_DEC_INVALID_CODE_BOOK = 0x4006, /*!< An invalid codebook was signalled. Most probably the bitstream is corrupt, or the system 393 crashed. */ 394 AAC_DEC_UNSUPPORTED_PREDICTION = 0x4007, /*!< Predictor found, but not supported in the AAC Low Complexity profile. Most probably the 395 bitstream is corrupt, or has a wrong format. */ 396 AAC_DEC_UNSUPPORTED_CCE = 0x4008, /*!< A CCE element was found which is not supported. Most probably the bitstream is corrupt, or 397 has a wrong format. */ 398 AAC_DEC_UNSUPPORTED_LFE = 0x4009, /*!< A LFE element was found which is not supported. Most probably the bitstream is corrupt, or 399 has a wrong format. */ 400 AAC_DEC_UNSUPPORTED_GAIN_CONTROL_DATA = 0x400A, /*!< Gain control data found but not supported. Most probably the bitstream is corrupt, or has 401 a wrong format. */ 402 AAC_DEC_UNSUPPORTED_SBA = 0x400B, /*!< SBA found, but currently not supported in the BSAC profile. */ 403 AAC_DEC_TNS_READ_ERROR = 0x400C, /*!< Error while reading TNS data. Most probably the bitstream is corrupt or the system 404 crashed. */ 405 AAC_DEC_RVLC_ERROR = 0x400D, /*!< Error while decoding error resillient data. */ 406 aac_dec_decode_error_end = 0x4FFF, 407 408 /* Ancillary data errors. Output buffer is valid. */ 409 aac_dec_anc_data_error_start = 0x8000, 410 AAC_DEC_ANC_DATA_ERROR = 0x8001, /*!< Non severe error concerning the ancillary data handling. */ 411 AAC_DEC_TOO_SMALL_ANC_BUFFER = 0x8002, /*!< The registered ancillary data buffer is too small to receive the parsed data. */ 412 AAC_DEC_TOO_MANY_ANC_ELEMENTS = 0x8003, /*!< More than the allowed number of ancillary data elements should be written to buffer. */ 413 aac_dec_anc_data_error_end = 0x8FFF 414 415 416 } AAC_DECODER_ERROR; 417 418 419 /** Macro to identify initialization errors. */ 420 #define IS_INIT_ERROR(err) ( (((err)>=aac_dec_init_error_start) && ((err)<=aac_dec_init_error_end)) ? 1 : 0) 421 /** Macro to identify decode errors. */ 422 #define IS_DECODE_ERROR(err) ( (((err)>=aac_dec_decode_error_start) && ((err)<=aac_dec_decode_error_end)) ? 1 : 0) 423 /** Macro to identify if the audio output buffer contains valid samples after calling aacDecoder_DecodeFrame(). */ 424 #define IS_OUTPUT_VALID(err) ( ((err) == AAC_DEC_OK) || IS_DECODE_ERROR(err) ) 425 426 /** 427 * \brief AAC decoder setting parameters 428 */ 429 typedef enum 430 { 431 AAC_PCM_OUTPUT_INTERLEAVED = 0x0000, /*!< PCM output mode (1: interleaved (default); 0: not interleaved). */ 432 AAC_PCM_DUAL_CHANNEL_OUTPUT_MODE = 0x0002, /*!< Defines how the decoder processes two channel signals: \n 433 0: Leave both signals as they are (default). \n 434 1: Create a dual mono output signal from channel 1. \n 435 2: Create a dual mono output signal from channel 2. \n 436 3: Create a dual mono output signal by mixing both channels (L' = R' = 0.5*Ch1 + 0.5*Ch2). */ 437 AAC_PCM_OUTPUT_CHANNEL_MAPPING = 0x0003, /*!< Output buffer channel ordering. 0: MPEG PCE style order, 1: WAV file channel order (default). */ 438 AAC_PCM_LIMITER_ENABLE = 0x0004, /*!< Enable signal level limiting. \n 439 -1: Auto-config. Enable limiter for all non-lowdelay configurations by default. \n 440 0: Disable limiter in general. \n 441 1: Enable limiter always. 442 It is recommended to call the decoder with a AACDEC_CLRHIST flag to reset all states when 443 the limiter switch is changed explicitly. */ 444 AAC_PCM_LIMITER_ATTACK_TIME = 0x0005, /*!< Signal level limiting attack time in ms. 445 Default confguration is 15 ms. Adjustable range from 1 ms to 15 ms. */ 446 AAC_PCM_LIMITER_RELEAS_TIME = 0x0006, /*!< Signal level limiting release time in ms. 447 Default configuration is 50 ms. Adjustable time must be larger than 0 ms. */ 448 AAC_PCM_MIN_OUTPUT_CHANNELS = 0x0011, /*!< Minimum number of PCM output channels. If higher than the number of encoded audio channels, 449 a simple channel extension is applied. \n 450 -1, 0: Disable channel extenstion feature. The decoder output contains the same number of 451 channels as the encoded bitstream. \n 452 1: This value is currently needed only together with the mix-down feature. See 453 ::AAC_PCM_MAX_OUTPUT_CHANNELS and note 2 below. \n 454 2: Encoded mono signals will be duplicated to achieve a 2/0/0.0 channel output 455 configuration. \n 456 6: The decoder trys to reorder encoded signals with less than six channels to achieve 457 a 3/0/2.1 channel output signal. Missing channels will be filled with a zero signal. 458 If reordering is not possible the empty channels will simply be appended. Only 459 available if instance is configured to support multichannel output. \n 460 8: The decoder trys to reorder encoded signals with less than eight channels to 461 achieve a 3/0/4.1 channel output signal. Missing channels will be filled with a 462 zero signal. If reordering is not possible the empty channels will simply be 463 appended. Only available if instance is configured to support multichannel output.\n 464 NOTE: \n 465 1. The channel signalling (CStreamInfo::pChannelType and CStreamInfo::pChannelIndices) 466 will not be modified. Added empty channels will be signalled with channel type 467 AUDIO_CHANNEL_TYPE::ACT_NONE. \n 468 2. If the parameter value is greater than that of ::AAC_PCM_MAX_OUTPUT_CHANNELS both will 469 be set to the same value. \n 470 3. This parameter does not affect MPEG Surround processing. */ 471 AAC_PCM_MAX_OUTPUT_CHANNELS = 0x0012, /*!< Maximum number of PCM output channels. If lower than the number of encoded audio channels, 472 downmixing is applied accordingly. If dedicated metadata is available in the stream it 473 will be used to achieve better mixing results. \n 474 -1, 0: Disable downmixing feature. The decoder output contains the same number of channels 475 as the encoded bitstream. \n 476 1: All encoded audio configurations with more than one channel will be mixed down to 477 one mono output signal. \n 478 2: The decoder performs a stereo mix-down if the number encoded audio channels is 479 greater than two. \n 480 6: If the number of encoded audio channels is greater than six the decoder performs a 481 mix-down to meet the target output configuration of 3/0/2.1 channels. Only 482 available if instance is configured to support multichannel output. \n 483 8: This value is currently needed only together with the channel extension feature. 484 See ::AAC_PCM_MIN_OUTPUT_CHANNELS and note 2 below. Only available if instance is 485 configured to support multichannel output. \n 486 NOTE: \n 487 1. Down-mixing of any seven or eight channel configuration not defined in ISO/IEC 14496-3 488 PDAM 4 is not supported by this software version. \n 489 2. If the parameter value is greater than zero but smaller than ::AAC_PCM_MIN_OUTPUT_CHANNELS 490 both will be set to same value. \n 491 3. The operating mode of the MPEG Surround module will be set accordingly. \n 492 4. Setting this param with any value will disable the binaural processing of the MPEG 493 Surround module (::AAC_MPEGS_BINAURAL_ENABLE=0). */ 494 495 AAC_CONCEAL_METHOD = 0x0100, /*!< Error concealment: Processing method. \n 496 0: Spectral muting. \n 497 1: Noise substitution (see ::CONCEAL_NOISE). \n 498 2: Energy interpolation (adds additional signal delay of one frame, see ::CONCEAL_INTER). \n */ 499 500 AAC_DRC_BOOST_FACTOR = 0x0200, /*!< Dynamic Range Control: Scaling factor for boosting gain values. 501 Defines how the boosting DRC factors (conveyed in the bitstream) will be applied to the 502 decoded signal. The valid values range from 0 (don't apply boost factors) to 127 (fully 503 apply all boosting factors). */ 504 AAC_DRC_ATTENUATION_FACTOR = 0x0201, /*!< Dynamic Range Control: Scaling factor for attenuating gain values. Same as 505 AAC_DRC_BOOST_FACTOR but for attenuating DRC factors. */ 506 AAC_DRC_REFERENCE_LEVEL = 0x0202, /*!< Dynamic Range Control: Target reference level. Defines the level below full-scale 507 (quantized in steps of 0.25dB) to which the output audio signal will be normalized to by 508 the DRC module. The valid values range from 0 (full-scale) to 127 (31.75 dB below 509 full-scale). The value smaller than 0 switches off normalization. */ 510 AAC_DRC_HEAVY_COMPRESSION = 0x0203, /*!< Dynamic Range Control: En-/Disable DVB specific heavy compression (aka RF mode). 511 If set to 1, the decoder will apply the compression values from the DVB specific ancillary 512 data field. At the same time the MPEG-4 Dynamic Range Control tool will be disabled. By 513 default heavy compression is disabled. */ 514 515 AAC_QMF_LOWPOWER = 0x0300, /*!< Quadrature Mirror Filter (QMF) Bank processing mode. \n 516 -1: Use internal default. Implies MPEG Surround partially complex accordingly. \n 517 0: Use complex QMF data mode. \n 518 1: Use real (low power) QMF data mode. \n */ 519 520 AAC_MPEGS_ENABLE = 0x0500, /*!< MPEG Surround: Allow/Disable decoding of MPS content. Available only for decoders with MPEG 521 Surround support. */ 522 523 AAC_TPDEC_CLEAR_BUFFER = 0x0603 /*!< Clear internal bit stream buffer of transport layers. The decoder will start decoding 524 at new data passed after this event and any previous data is discarded. */ 525 526 } AACDEC_PARAM; 527 528 /** 529 * \brief This structure gives information about the currently decoded audio data. 530 * All fields are read-only. 531 */ 532 typedef struct 533 { 534 /* These five members are the only really relevant ones for the user. */ 535 INT sampleRate; /*!< The samplerate in Hz of the fully decoded PCM audio signal (after SBR processing). */ 536 INT frameSize; /*!< The frame size of the decoded PCM audio signal. \n 537 1024 or 960 for AAC-LC \n 538 2048 or 1920 for HE-AAC (v2) \n 539 512 or 480 for AAC-LD and AAC-ELD */ 540 INT numChannels; /*!< The number of output audio channels in the decoded and interleaved PCM audio signal. */ 541 AUDIO_CHANNEL_TYPE *pChannelType; /*!< Audio channel type of each output audio channel. */ 542 UCHAR *pChannelIndices; /*!< Audio channel index for each output audio channel. 543 See ISO/IEC 13818-7:2005(E), 8.5.3.2 Explicit channel mapping using a program_config_element() */ 544 /* Decoder internal members. */ 545 INT aacSampleRate; /*!< Sampling rate in Hz without SBR (from configuration info). */ 546 INT profile; /*!< MPEG-2 profile (from file header) (-1: not applicable (e. g. MPEG-4)). */ 547 AUDIO_OBJECT_TYPE aot; /*!< Audio Object Type (from ASC): is set to the appropriate value for MPEG-2 bitstreams (e. g. 2 for AAC-LC). */ 548 INT channelConfig; /*!< Channel configuration (0: PCE defined, 1: mono, 2: stereo, ... */ 549 INT bitRate; /*!< Instantaneous bit rate. */ 550 INT aacSamplesPerFrame; /*!< Samples per frame for the AAC core (from ASC). \n 551 1024 or 960 for AAC-LC \n 552 512 or 480 for AAC-LD and AAC-ELD */ 553 INT aacNumChannels; /*!< The number of audio channels after AAC core processing (before PS or MPS processing). 554 CAUTION: This are not the final number of output channels! */ 555 AUDIO_OBJECT_TYPE extAot; /*!< Extension Audio Object Type (from ASC) */ 556 INT extSamplingRate; /*!< Extension sampling rate in Hz (from ASC) */ 557 558 UINT outputDelay; /*!< The number of samples the output is additionally delayed by the decoder. */ 559 560 UINT flags; /*!< Copy of internal flags. Only to be written by the decoder, and only to be read externally. */ 561 562 SCHAR epConfig; /*!< epConfig level (from ASC): only level 0 supported, -1 means no ER (e. g. AOT=2, MPEG-2 AAC, etc.) */ 563 564 /* Statistics */ 565 INT numLostAccessUnits; /*!< This integer will reflect the estimated amount of lost access units in case aacDecoder_DecodeFrame() 566 returns AAC_DEC_TRANSPORT_SYNC_ERROR. It will be < 0 if the estimation failed. */ 567 568 UINT numTotalBytes; /*!< This is the number of total bytes that have passed through the decoder. */ 569 UINT numBadBytes; /*!< This is the number of total bytes that were considered with errors from numTotalBytes. */ 570 UINT numTotalAccessUnits; /*!< This is the number of total access units that have passed through the decoder. */ 571 UINT numBadAccessUnits; /*!< This is the number of total access units that were considered with errors from numTotalBytes. */ 572 573 /* Metadata */ 574 SCHAR drcProgRefLev; /*!< DRC program reference level. Defines the reference level below full-scale. 575 It is quantized in steps of 0.25dB. The valid values range from 0 (0 dBFS) to 127 (-31.75 dBFS). 576 It is used to reflect the average loudness of the audio in LKFS accoring to ITU-R BS 1770. 577 If no level has been found in the bitstream the value is -1. */ 578 SCHAR drcPresMode; /*!< DRC presentation mode. According to ETSI TS 101 154, this field indicates whether 579 light (MPEG-4 Dynamic Range Control tool) or heavy compression (DVB heavy compression) 580 dynamic range control shall take priority on the outputs. 581 For details, see ETSI TS 101 154, table C.33. Possible values are: \n 582 -1: No corresponding metadata found in the bitstream \n 583 0: DRC presentation mode not indicated \n 584 1: DRC presentation mode 1 \n 585 2: DRC presentation mode 2 \n 586 3: Reserved */ 587 588 } CStreamInfo; 589 590 591 typedef struct AAC_DECODER_INSTANCE *HANDLE_AACDECODER; /*!< Pointer to a AAC decoder instance. */ 592 593 #ifdef __cplusplus 594 extern "C" 595 { 596 #endif 597 598 /** 599 * \brief Initialize ancillary data buffer. 600 * 601 * \param self AAC decoder handle. 602 * \param buffer Pointer to (external) ancillary data buffer. 603 * \param size Size of the buffer pointed to by buffer. 604 * \return Error code. 605 */ 606 LINKSPEC_H AAC_DECODER_ERROR 607 aacDecoder_AncDataInit ( HANDLE_AACDECODER self, 608 UCHAR *buffer, 609 int size ); 610 611 /** 612 * \brief Get one ancillary data element. 613 * 614 * \param self AAC decoder handle. 615 * \param index Index of the ancillary data element to get. 616 * \param ptr Pointer to a buffer receiving a pointer to the requested ancillary data element. 617 * \param size Pointer to a buffer receiving the length of the requested ancillary data element. 618 * \return Error code. 619 */ 620 LINKSPEC_H AAC_DECODER_ERROR 621 aacDecoder_AncDataGet ( HANDLE_AACDECODER self, 622 int index, 623 UCHAR **ptr, 624 int *size ); 625 626 /** 627 * \brief Set one single decoder parameter. 628 * 629 * \param self AAC decoder handle. 630 * \param param Parameter to be set. 631 * \param value Parameter value. 632 * \return Error code. 633 */ 634 LINKSPEC_H AAC_DECODER_ERROR 635 aacDecoder_SetParam ( const HANDLE_AACDECODER self, 636 const AACDEC_PARAM param, 637 const INT value ); 638 639 640 /** 641 * \brief Get free bytes inside decoder internal buffer 642 * \param self Handle of AAC decoder instance 643 * \param pFreeBytes Pointer to variable receving amount of free bytes inside decoder internal buffer 644 * \return Error code 645 */ 646 LINKSPEC_H AAC_DECODER_ERROR 647 aacDecoder_GetFreeBytes ( const HANDLE_AACDECODER self, 648 UINT *pFreeBytes); 649 650 /** 651 * \brief Open an AAC decoder instance 652 * \param transportFmt The transport type to be used 653 * \return AAC decoder handle 654 */ 655 LINKSPEC_H HANDLE_AACDECODER 656 aacDecoder_Open ( TRANSPORT_TYPE transportFmt, UINT nrOfLayers ); 657 658 /** 659 * \brief Explicitly configure the decoder by passing a raw AudioSpecificConfig (ASC) or a StreamMuxConfig (SMC), 660 * contained in a binary buffer. This is required for MPEG-4 and Raw Packets file format bitstreams 661 * as well as for LATM bitstreams with no in-band SMC. If the transport format is LATM with or without 662 * LOAS, configuration is assumed to be an SMC, for all other file formats an ASC. 663 * 664 * \param self AAC decoder handle. 665 * \param conf Pointer to an unsigned char buffer containing the binary configuration buffer (either ASC or SMC). 666 * \param length Length of the configuration buffer in bytes. 667 * \return Error code. 668 */ 669 LINKSPEC_H AAC_DECODER_ERROR 670 aacDecoder_ConfigRaw ( HANDLE_AACDECODER self, 671 UCHAR *conf[], 672 const UINT length[] ); 673 674 675 /** 676 * \brief Fill AAC decoder's internal input buffer with bitstream data from the external input buffer. 677 * The function only copies such data as long as the decoder-internal input buffer is not full. 678 * So it grabs whatever it can from pBuffer and returns information (bytesValid) so that at a 679 * subsequent call of %aacDecoder_Fill(), the right position in pBuffer can be determined to 680 * grab the next data. 681 * 682 * \param self AAC decoder handle. 683 * \param pBuffer Pointer to external input buffer. 684 * \param bufferSize Size of external input buffer. This argument is required because decoder-internally 685 * we need the information to calculate the offset to pBuffer, where the next 686 * available data is, which is then fed into the decoder-internal buffer (as much 687 * as possible). Our example framework implementation fills the buffer at pBuffer 688 * again, once it contains no available valid bytes anymore (meaning bytesValid equal 0). 689 * \param bytesValid Number of bitstream bytes in the external bitstream buffer that have not yet been 690 * copied into the decoder's internal bitstream buffer by calling this function. 691 * The value is updated according to the amount of newly copied bytes. 692 * \return Error code. 693 */ 694 LINKSPEC_H AAC_DECODER_ERROR 695 aacDecoder_Fill ( HANDLE_AACDECODER self, 696 UCHAR *pBuffer[], 697 const UINT bufferSize[], 698 UINT *bytesValid ); 699 700 #define AACDEC_CONCEAL 1 /*!< Flag for aacDecoder_DecodeFrame(): Trigger the built-in error concealment module \ 701 to generate a substitute signal for one lost frame. New input data will not be 702 considered. */ 703 #define AACDEC_FLUSH 2 /*!< Flag for aacDecoder_DecodeFrame(): Flush all filterbanks to get all delayed audio \ 704 without having new input data. Thus new input data will not be considered.*/ 705 #define AACDEC_INTR 4 /*!< Flag for aacDecoder_DecodeFrame(): Signal an input bit stream data discontinuity. \ 706 Resync any internals as necessary. */ 707 #define AACDEC_CLRHIST 8 /*!< Flag for aacDecoder_DecodeFrame(): Clear all signal delay lines and history buffers.\ 708 CAUTION: This can cause discontinuities in the output signal. */ 709 710 /** 711 * \brief Decode one audio frame 712 * 713 * \param self AAC decoder handle. 714 * \param pTimeData Pointer to external output buffer where the decoded PCM samples will be stored into. 715 * \param flags Bit field with flags for the decoder: \n 716 * (flags & AACDEC_CONCEAL) == 1: Do concealment. \n 717 * (flags & AACDEC_FLUSH) == 2: Discard input data. Flush filter banks (output delayed audio). \n 718 * (flags & AACDEC_INTR) == 4: Input data is discontinuous. Resynchronize any internals as necessary. 719 * \return Error code. 720 */ 721 LINKSPEC_H AAC_DECODER_ERROR 722 aacDecoder_DecodeFrame ( HANDLE_AACDECODER self, 723 INT_PCM *pTimeData, 724 const INT timeDataSize, 725 const UINT flags ); 726 727 /** 728 * \brief De-allocate all resources of an AAC decoder instance. 729 * 730 * \param self AAC decoder handle. 731 * \return void 732 */ 733 LINKSPEC_H void aacDecoder_Close ( HANDLE_AACDECODER self ); 734 735 /** 736 * \brief Get CStreamInfo handle from decoder. 737 * 738 * \param self AAC decoder handle. 739 * \return Reference to requested CStreamInfo. 740 */ 741 LINKSPEC_H CStreamInfo* aacDecoder_GetStreamInfo( HANDLE_AACDECODER self ); 742 743 /** 744 * \brief Get decoder library info. 745 * 746 * \param info Pointer to an allocated LIB_INFO structure. 747 * \return 0 on success 748 */ 749 LINKSPEC_H INT aacDecoder_GetLibInfo( LIB_INFO *info ); 750 751 752 #ifdef __cplusplus 753 } 754 #endif 755 756 #endif /* AACDECODER_LIB_H */ 757
