1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5� Copyright  1995 - 2015 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/*****************************  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
99This document describes the high-level interface and usage of the ISO/MPEG-2/4 AAC Decoder
100library developed by the Fraunhofer Institute for Integrated Circuits (IIS).
101Depending on the library configuration, it implements decoding of AAC-LC (Low-Complexity),
102HE-AAC (High-Efficiency AAC, v1 and v2), AAC-LD (Low-Delay) and AAC-ELD (Enhanced Low-Delay).
103
104All references to SBR (Spectral Band Replication) are only applicable to HE-AAC and AAC-ELD
105versions of the library. All references to PS (Parametric Stereo) are only applicable to
106HE-AAC v2 versions of the library.
107
108\section DecoderBasics Decoder Basics
109
110This document can only give a rough overview about the ISO/MPEG-2 and ISO/MPEG-4 AAC audio
111coding standard. To understand all the terms in this document, you are encouraged to read
112the 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
118MPEG Advanced Audio Coding is based on a time-to-frequency mapping of the signal. The signal
119is partitioned into overlapping portions and transformed into frequency domain. The spectral
120components are then quantized and coded.\n
121An MPEG2 or MPEG4 AAC audio bitstream is composed of frames. Contrary to MPEG-1/2 Layer-3 (mp3),
122the length of individual frames is not restricted to a fixed number of bytes, but can take on
123any length between 1 and 768 bytes.
124
125
126\page LIBUSE Library Usage
127
128\section InterfaceDescritpion API Description
129
130All API header files are located in the folder /include of the release package. They are described in
131detail in this document. All header files are provided for usage in C/C++ programs. The AAC decoder library
132API functions are located at aacdecoder_lib.h.
133
134In 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
139For decoding of ISO/MPEG-2/4 AAC or HE-AAC v2 bitstreams the following sequence is mandatory. Input read
140and output write functions as well as the corresponding open and close functions are left out, since they
141may be implemented differently according to the user's specific requirements. The example implementation in
142main.cpp uses file-based input/output, and in such case call mpegFileRead_Open() to open an input file and
143to allocate memory for the required structures, and the corresponding mpegFileRead_Close() to close opened
144files and to de-allocate associated structures. mpegFileRead_Open() tries to detect the bitstream format and
145in case of MPEG-4 file format or Raw Packets file format (a Fraunhofer IIS proprietary format) reads the Audio
146Specific Config data (ASC). An unsuccessful attempt to recognize the bitstream format requires the user to
147provide this information manually. For any other bitstream formats that are usually applicable in streaming
148applications, the decoder itself will try to synchronize and parse the given bitstream fragment using the
149FDK 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
155aacDecoder_ConfigRaw() to pass it to the decoder and before the decoding process starts. If this data is
156not available in advance, the decoder will get it from the bitstream  and configure itself while decoding
157with 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).
161If it is very small like just 4, aacDecoder_DecodeFrame() will
162repeatedly return ::AAC_DEC_NOT_ENOUGH_BITS until enough bits were fed by aacDecoder_Fill(). Only read data
163when this buffer has completely been processed and is then empty. For file-based input execute
164mpegFileRead_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
166external 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
169client's responsibility to allocate a buffer which is large enough to hold this output data.
170\skipline aacDecoder_DecodeFrame
171If the bitstream's configuration (number of channels, sample rate, frame size) is not known in advance, you may
172call aacDecoder_GetStreamInfo() to retrieve a structure containing this information and then initialize an audio
173output device. In the example main.cpp, if the number of channels or the sample rate has changed since program
174start or since the previously decoded frame, the audio output device will be re-initialized. If WAVE file output
175is 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
184There are three main buffers in an AAC decoder application. One external input buffer to hold bitstream
185data from file I/O or elsewhere, one decoder-internal input buffer, and one to hold the decoded output
186PCM sample data, whereas this output buffer may overlap with the external input buffer.
187
188The external input buffer is set in the example framework main.cpp and its size is defined by ::IN_BUF_SIZE.
189You may freely choose different sizes here. To feed the data to the decoder-internal input buffer, use the
190function aacDecoder_Fill(). This function returns important information about how many bytes in the
191external input buffer have not yet been copied into the internal input buffer (variable bytesValid).
192Once the external buffer has been fully copied, it can be re-filled again.
193In case you want to re-fill it when there are still unprocessed bytes (bytesValid is unequal 0), you
194would have to additionally perform a memcpy(), so that just means unnecessary computational overhead
195and 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
199The size of the decoder-internal input buffer is set in tpdec_lib.h (see define ::TRANSPORTDEC_INBUF_SIZE).
200You 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
205So for example a stereo decoder:
206
207\f[
208TRANSPORTDEC\_INBUF\_SIZE = 2 * 768 = 1536 => 2048
209\f]
210
211tpdec_lib.h and TRANSPORTDEC_INBUF_SIZE are not part of the decoder's library interface. Therefore
212only source-code clients may change this setting. If you received a library release, please ask us and
213we 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
219The decoded audio output format is indicated by a set of variables of the CStreamInfo structure.
220While the members sampleRate, frameSize and numChannels might be quite self explaining,
221pChannelType and pChannelIndices might require some more detailed explanation.
222
223These two arrays indicate what is each output channel supposed to be. Both array have
224CStreamInfo::numChannels cells. Each cell of pChannelType indicates the channel type, described in
225the enum ::AUDIO_CHANNEL_TYPE defined in FDK_audio.h. The cells of pChannelIndices indicate the sub index
226among the channels starting with 0 among all channels of the same audio channel type.
227
228The indexing scheme is the same as for MPEG-2/4. Thus indices are counted upwards starting from the front
229direction (thus a center channel if any, will always be index 0). Then the indices count up, starting always
230with the left side, pairwise from front toward back. For detailed explanation, please refer to
231ISO/IEC 13818-7:2005(E), chapter 8.5.3.2.
232
233In case a Program Config is included in the audio configuration, the channel mapping described within
234it will be adopted.
235
236In case of MPEG-D Surround the channel mapping will follow the same criteria described in ISO/IEC 13818-7:2005(E),
237but adding corresponding top channels to the channel types front, side and back, in order to avoid any
238loss of information.
239
240\section OutputFormatChange Changing the audio output format
241
242The channel interleaving scheme and the actual channel order can be changed at runtime through the
243parameters ::AAC_PCM_OUTPUT_INTERLEAVED and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING. See the description of those
244parameters and the decoder library function aacDecoder_SetParam() for more detail.
245
246\section OutputFormatExample Channel mapping examples
247
248The following examples illustrate the location of individual audio samples in the audio buffer that
249is passed to aacDecoder_DecodeFrame() and the expected data in the CStreamInfo structure which can be obtained
250by calling aacDecoder_GetStreamInfo().
251
252\subsection ExamplesStereo Stereo
253
254In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 0 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
255a AAC-LC bit stream which has channelConfiguration = 2 in its audio specific config would lead
256to the following values in CStreamInfo:
257
258CStreamInfo::numChannels = 2
259
260CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT }
261
262CStreamInfo::pChannelIndices = { 0, 1 }
263
264Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 0, the audio channels will be located as contiguous blocks
265in 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
272Where N equals to CStreamInfo::frameSize .
273
274\subsection ExamplesSurround Surround 5.1
275
276In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
277a AAC-LC bit stream which has channelConfiguration = 6 in its audio specific config, would lead
278to the following values in CStreamInfo:
279
280CStreamInfo::numChannels = 6
281
282CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT, ::ACT_FRONT, ::ACT_LFE, ::ACT_BACK, ::ACT_BACK }
283
284CStreamInfo::pChannelIndices = { 1, 2, 0, 0, 0, 1 }
285
286Since ::AAC_PCM_OUTPUT_CHANNEL_MAPPING is 1, WAV file channel ordering will be used. For a 5.1 channel
287scheme, thus the channels would be: front left, front right, center, LFE, surround left, surround right.
288Thus the third channel is the center channel, receiving the index 0. The other front channels are
289front left, front right being placed as first and second channels with indices 1 and 2 correspondingly.
290There is only one LFE, placed as the fourth channel and index 0. Finally both surround
291channels get the type definition ACT_BACK, and the indices 0 and 1.
292
293Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 1, the audio channels will be placed in the output buffer
294as 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
312Where N equals to CStreamInfo::frameSize .
313
314\subsection ExamplesArib ARIB coding mode 2/1
315
316In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
317in 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,
318would lead to the following values in CStreamInfo:
319
320CStreamInfo::numChannels = 3
321
322CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT,:: ACT_BACK }
323
324CStreamInfo::pChannelIndices = { 0, 1, 0 }
325
326The 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
337Where 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 */
354typedef 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_OUTPUT_BUFFER_TOO_SMALL        = 0x200C,  /*!< The provided output buffer is too small. */
382  aac_dec_init_error_end                 = 0x2FFF,
383
384  /* Decode errors. Output buffer is valid but concealed. */
385  aac_dec_decode_error_start             = 0x4000,
386  AAC_DEC_TRANSPORT_ERROR                = 0x4001,  /*!< The transport decoder encountered an unexpected error. */
387  AAC_DEC_PARSE_ERROR                    = 0x4002,  /*!< Error while parsing the bitstream. Most probably it is corrupted, or the system crashed. */
388  AAC_DEC_UNSUPPORTED_EXTENSION_PAYLOAD  = 0x4003,  /*!< Error while parsing the extension payload of the bitstream. The extension payload type
389                                                         found is not supported. */
390  AAC_DEC_DECODE_FRAME_ERROR             = 0x4004,  /*!< The parsed bitstream value is out of range. Most probably the bitstream is corrupt, or
391                                                         the system crashed. */
392  AAC_DEC_CRC_ERROR                      = 0x4005,  /*!< The embedded CRC did not match. */
393  AAC_DEC_INVALID_CODE_BOOK              = 0x4006,  /*!< An invalid codebook was signalled. Most probably the bitstream is corrupt, or the system
394                                                         crashed. */
395  AAC_DEC_UNSUPPORTED_PREDICTION         = 0x4007,  /*!< Predictor found, but not supported in the AAC Low Complexity profile. Most probably the
396                                                         bitstream is corrupt, or has a wrong format. */
397  AAC_DEC_UNSUPPORTED_CCE                = 0x4008,  /*!< A CCE element was found which is not supported. Most probably the bitstream is corrupt, or
398                                                         has a wrong format. */
399  AAC_DEC_UNSUPPORTED_LFE                = 0x4009,  /*!< A LFE element was found which is not supported. Most probably the bitstream is corrupt, or
400                                                         has a wrong format. */
401  AAC_DEC_UNSUPPORTED_GAIN_CONTROL_DATA  = 0x400A,  /*!< Gain control data found but not supported. Most probably the bitstream is corrupt, or has
402                                                         a wrong format. */
403  AAC_DEC_UNSUPPORTED_SBA                = 0x400B,  /*!< SBA found, but currently not supported in the BSAC profile. */
404  AAC_DEC_TNS_READ_ERROR                 = 0x400C,  /*!< Error while reading TNS data. Most probably the bitstream is corrupt or the system
405                                                         crashed. */
406  AAC_DEC_RVLC_ERROR                     = 0x400D,  /*!< Error while decoding error resillient data. */
407  aac_dec_decode_error_end               = 0x4FFF,
408
409  /* Ancillary data errors. Output buffer is valid. */
410  aac_dec_anc_data_error_start           = 0x8000,
411  AAC_DEC_ANC_DATA_ERROR                 = 0x8001,  /*!< Non severe error concerning the ancillary data handling. */
412  AAC_DEC_TOO_SMALL_ANC_BUFFER           = 0x8002,  /*!< The registered ancillary data buffer is too small to receive the parsed data. */
413  AAC_DEC_TOO_MANY_ANC_ELEMENTS          = 0x8003,  /*!< More than the allowed number of ancillary data elements should be written to buffer. */
414  aac_dec_anc_data_error_end             = 0x8FFF
415
416
417} AAC_DECODER_ERROR;
418
419
420/** Macro to identify initialization errors. */
421#define IS_INIT_ERROR(err)   ( (((err)>=aac_dec_init_error_start)   && ((err)<=aac_dec_init_error_end))   ? 1 : 0)
422/** Macro to identify decode errors. */
423#define IS_DECODE_ERROR(err) ( (((err)>=aac_dec_decode_error_start) && ((err)<=aac_dec_decode_error_end)) ? 1 : 0)
424/** Macro to identify if the audio output buffer contains valid samples after calling aacDecoder_DecodeFrame(). */
425#define IS_OUTPUT_VALID(err) ( ((err) == AAC_DEC_OK) || IS_DECODE_ERROR(err) )
426
427/**
428 * \brief AAC decoder setting parameters
429 */
430typedef enum
431{
432  AAC_PCM_OUTPUT_INTERLEAVED              = 0x0000,  /*!< PCM output mode (1: interleaved (default); 0: not interleaved). */
433  AAC_PCM_DUAL_CHANNEL_OUTPUT_MODE        = 0x0002,  /*!< Defines how the decoder processes two channel signals: \n
434                                                          0: Leave both signals as they are (default). \n
435                                                          1: Create a dual mono output signal from channel 1. \n
436                                                          2: Create a dual mono output signal from channel 2. \n
437                                                          3: Create a dual mono output signal by mixing both channels (L' = R' = 0.5*Ch1 + 0.5*Ch2). */
438  AAC_PCM_OUTPUT_CHANNEL_MAPPING          = 0x0003,  /*!< Output buffer channel ordering. 0: MPEG PCE style order, 1: WAV file channel order (default). */
439  AAC_PCM_LIMITER_ENABLE                  = 0x0004,  /*!< Enable signal level limiting. \n
440                                                          -1: Auto-config. Enable limiter for all non-lowdelay configurations by default. \n
441                                                           0: Disable limiter in general. \n
442                                                           1: Enable limiter always.
443                                                          It is recommended to call the decoder with a AACDEC_CLRHIST flag to reset all states when
444                                                          the limiter switch is changed explicitly. */
445  AAC_PCM_LIMITER_ATTACK_TIME             = 0x0005,  /*!< Signal level limiting attack time in ms.
446                                                          Default confguration is 15 ms. Adjustable range from 1 ms to 15 ms. */
447  AAC_PCM_LIMITER_RELEAS_TIME             = 0x0006,  /*!< Signal level limiting release time in ms.
448                                                          Default configuration is 50 ms. Adjustable time must be larger than 0 ms. */
449  AAC_PCM_MIN_OUTPUT_CHANNELS             = 0x0011,  /*!< Minimum number of PCM output channels. If higher than the number of encoded audio channels,
450                                                          a simple channel extension is applied. \n
451                                                          -1, 0: Disable channel extenstion feature. The decoder output contains the same number of
452                                                                 channels as the encoded bitstream. \n
453                                                           1:    This value is currently needed only together with the mix-down feature. See
454                                                                 ::AAC_PCM_MAX_OUTPUT_CHANNELS and note 2 below. \n
455                                                           2:    Encoded mono signals will be duplicated to achieve a 2/0/0.0 channel output
456                                                                 configuration. \n
457                                                           6:    The decoder trys to reorder encoded signals with less than six channels to achieve
458                                                                 a 3/0/2.1 channel output signal. Missing channels will be filled with a zero signal.
459                                                                 If reordering is not possible the empty channels will simply be appended. Only
460                                                                 available if instance is configured to support multichannel output. \n
461                                                           8:    The decoder trys to reorder encoded signals with less than eight channels to
462                                                                 achieve a 3/0/4.1 channel output signal. Missing channels will be filled with a
463                                                                 zero signal. If reordering is not possible the empty channels will simply be
464                                                                 appended. Only available if instance is configured to support multichannel output.\n
465                                                          NOTE: \n
466                                                            1. The channel signalling (CStreamInfo::pChannelType and CStreamInfo::pChannelIndices)
467                                                               will not be modified. Added empty channels will be signalled with channel type
468                                                               AUDIO_CHANNEL_TYPE::ACT_NONE. \n
469                                                            2. If the parameter value is greater than that of ::AAC_PCM_MAX_OUTPUT_CHANNELS both will
470                                                               be set to the same value. \n
471                                                            3. This parameter does not affect MPEG Surround processing. */
472  AAC_PCM_MAX_OUTPUT_CHANNELS             = 0x0012,  /*!< Maximum number of PCM output channels. If lower than the number of encoded audio channels,
473                                                          downmixing is applied accordingly. If dedicated metadata is available in the stream it
474                                                          will be used to achieve better mixing results. \n
475                                                          -1, 0: Disable downmixing feature. The decoder output contains the same number of channels
476                                                                 as the encoded bitstream. \n
477                                                           1:    All encoded audio configurations with more than one channel will be mixed down to
478                                                                 one mono output signal. \n
479                                                           2:    The decoder performs a stereo mix-down if the number encoded audio channels is
480                                                                 greater than two. \n
481                                                           6:    If the number of encoded audio channels is greater than six the decoder performs a
482                                                                 mix-down to meet the target output configuration of 3/0/2.1 channels. Only
483                                                                 available if instance is configured to support multichannel output. \n
484                                                           8:    This value is currently needed only together with the channel extension feature.
485                                                                 See ::AAC_PCM_MIN_OUTPUT_CHANNELS and note 2 below. Only available if instance is
486                                                                 configured to support multichannel output. \n
487                                                          NOTE: \n
488                                                            1. Down-mixing of any seven or eight channel configuration not defined in ISO/IEC 14496-3
489                                                               PDAM 4 is not supported by this software version. \n
490                                                            2. If the parameter value is greater than zero but smaller than ::AAC_PCM_MIN_OUTPUT_CHANNELS
491                                                               both will be set to same value. \n
492                                                            3. The operating mode of the MPEG Surround module will be set accordingly. \n
493                                                            4. Setting this param with any value will disable the binaural processing of the MPEG
494                                                               Surround module (::AAC_MPEGS_BINAURAL_ENABLE=0). */
495
496  AAC_CONCEAL_METHOD                      = 0x0100,  /*!< Error concealment: Processing method. \n
497                                                          0: Spectral muting. \n
498                                                          1: Noise substitution (see ::CONCEAL_NOISE). \n
499                                                          2: Energy interpolation (adds additional signal delay of one frame, see ::CONCEAL_INTER). \n */
500
501  AAC_DRC_BOOST_FACTOR                    = 0x0200,  /*!< Dynamic Range Control: Scaling factor for boosting gain values.
502                                                          Defines how the boosting DRC factors (conveyed in the bitstream) will be applied to the
503                                                          decoded signal. The valid values range from 0 (don't apply boost factors) to 127 (fully
504                                                          apply all boosting factors). */
505  AAC_DRC_ATTENUATION_FACTOR              = 0x0201,  /*!< Dynamic Range Control: Scaling factor for attenuating gain values. Same as
506                                                          AAC_DRC_BOOST_FACTOR but for attenuating DRC factors. */
507  AAC_DRC_REFERENCE_LEVEL                 = 0x0202,  /*!< Dynamic Range Control: Target reference level. Defines the level below full-scale
508                                                          (quantized in steps of 0.25dB) to which the output audio signal will be normalized to by
509                                                          the DRC module. The valid values range from 0 (full-scale) to 127 (31.75 dB below
510                                                          full-scale). The value smaller than 0 switches off normalization. */
511  AAC_DRC_HEAVY_COMPRESSION               = 0x0203,  /*!< Dynamic Range Control: En-/Disable DVB specific heavy compression (aka RF mode).
512                                                          If set to 1, the decoder will apply the compression values from the DVB specific ancillary
513                                                          data field. At the same time the MPEG-4 Dynamic Range Control tool will be disabled. By
514                                                          default heavy compression is disabled. */
515
516  AAC_QMF_LOWPOWER                        = 0x0300,  /*!< Quadrature Mirror Filter (QMF) Bank processing mode. \n
517                                                          -1: Use internal default. Implies MPEG Surround partially complex accordingly. \n
518                                                           0: Use complex QMF data mode. \n
519                                                           1: Use real (low power) QMF data mode. \n */
520
521  AAC_MPEGS_ENABLE                        = 0x0500,  /*!< MPEG Surround: Allow/Disable decoding of MPS content. Available only for decoders with MPEG
522                                                          Surround support. */
523
524  AAC_TPDEC_CLEAR_BUFFER                  = 0x0603   /*!< Clear internal bit stream buffer of transport layers. The decoder will start decoding
525                                                          at new data passed after this event and any previous data is discarded. */
526
527} AACDEC_PARAM;
528
529/**
530 * \brief This structure gives information about the currently decoded audio data.
531 *        All fields are read-only.
532 */
533typedef struct
534{
535  /* These five members are the only really relevant ones for the user.                                                            */
536  INT               sampleRate;          /*!< The samplerate in Hz of the fully decoded PCM audio signal (after SBR processing).   */
537  INT               frameSize;           /*!< The frame size of the decoded PCM audio signal. \n
538                                              1024 or 960 for AAC-LC \n
539                                              2048 or 1920 for HE-AAC (v2) \n
540                                              512 or 480 for AAC-LD and AAC-ELD                                                    */
541  INT               numChannels;         /*!< The number of output audio channels in the decoded and interleaved PCM audio signal. */
542  AUDIO_CHANNEL_TYPE *pChannelType;      /*!< Audio channel type of each output audio channel.                                     */
543  UCHAR             *pChannelIndices;    /*!< Audio channel index for each output audio channel.
544                                               See ISO/IEC 13818-7:2005(E), 8.5.3.2 Explicit channel mapping using a program_config_element() */
545  /* Decoder internal members. */
546  INT               aacSampleRate;       /*!< Sampling rate in Hz without SBR (from configuration info).                           */
547  INT               profile;             /*!< MPEG-2 profile (from file header) (-1: not applicable (e. g. MPEG-4)).               */
548  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). */
549  INT               channelConfig;       /*!< Channel configuration (0: PCE defined, 1: mono, 2: stereo, ...                       */
550  INT               bitRate;             /*!< Instantaneous bit rate.                   */
551  INT               aacSamplesPerFrame;  /*!< Samples per frame for the AAC core (from ASC). \n
552                                              1024 or 960 for AAC-LC \n
553                                              512 or 480 for AAC-LD and AAC-ELD         */
554  INT               aacNumChannels;      /*!< The number of audio channels after AAC core processing (before PS or MPS processing).
555                                              CAUTION: This are not the final number of output channels! */
556  AUDIO_OBJECT_TYPE extAot;              /*!< Extension Audio Object Type (from ASC)   */
557  INT               extSamplingRate;     /*!< Extension sampling rate in Hz (from ASC) */
558
559  UINT              outputDelay;         /*!< The number of samples the output is additionally delayed by the decoder. */
560
561  UINT              flags;               /*!< Copy of internal flags. Only to be written by the decoder, and only to be read externally. */
562
563  SCHAR             epConfig;            /*!< epConfig level (from ASC): only level 0 supported, -1 means no ER (e. g. AOT=2, MPEG-2 AAC, etc.)  */
564
565  /* Statistics */
566  INT               numLostAccessUnits;  /*!< This integer will reflect the estimated amount of lost access units in case aacDecoder_DecodeFrame()
567                                              returns AAC_DEC_TRANSPORT_SYNC_ERROR. It will be < 0 if the estimation failed. */
568
569  UINT              numTotalBytes;       /*!< This is the number of total bytes that have passed through the decoder. */
570  UINT              numBadBytes;         /*!< This is the number of total bytes that were considered with errors from numTotalBytes. */
571  UINT              numTotalAccessUnits; /*!< This is the number of total access units that have passed through the decoder. */
572  UINT              numBadAccessUnits;   /*!< This is the number of total access units that were considered with errors from numTotalBytes. */
573
574  /* Metadata */
575  SCHAR             drcProgRefLev;       /*!< DRC program reference level. Defines the reference level below full-scale.
576                                              It is quantized in steps of 0.25dB. The valid values range from 0 (0 dBFS) to 127 (-31.75 dBFS).
577                                              It is used to reflect the average loudness of the audio in LKFS accoring to ITU-R BS 1770.
578                                              If no level has been found in the bitstream the value is -1. */
579  SCHAR             drcPresMode;         /*!< DRC presentation mode. According to ETSI TS 101 154, this field indicates whether
580                                              light (MPEG-4 Dynamic Range Control tool) or heavy compression (DVB heavy compression)
581                                              dynamic range control shall take priority on the outputs.
582                                              For details, see ETSI TS 101 154, table C.33. Possible values are: \n
583                                              -1: No corresponding metadata found in the bitstream \n
584                                               0: DRC presentation mode not indicated \n
585                                               1: DRC presentation mode 1 \n
586                                               2: DRC presentation mode 2 \n
587                                               3: Reserved */
588
589} CStreamInfo;
590
591
592typedef struct AAC_DECODER_INSTANCE *HANDLE_AACDECODER;  /*!< Pointer to a AAC decoder instance. */
593
594#ifdef __cplusplus
595extern "C"
596{
597#endif
598
599/**
600 * \brief Initialize ancillary data buffer.
601 *
602 * \param self    AAC decoder handle.
603 * \param buffer  Pointer to (external) ancillary data buffer.
604 * \param size    Size of the buffer pointed to by buffer.
605 * \return        Error code.
606 */
607LINKSPEC_H AAC_DECODER_ERROR
608aacDecoder_AncDataInit ( HANDLE_AACDECODER self,
609                         UCHAR            *buffer,
610                         int               size );
611
612/**
613 * \brief Get one ancillary data element.
614 *
615 * \param self   AAC decoder handle.
616 * \param index  Index of the ancillary data element to get.
617 * \param ptr    Pointer to a buffer receiving a pointer to the requested ancillary data element.
618 * \param size   Pointer to a buffer receiving the length of the requested ancillary data element.
619 * \return       Error code.
620 */
621LINKSPEC_H AAC_DECODER_ERROR
622aacDecoder_AncDataGet ( HANDLE_AACDECODER self,
623                        int               index,
624                        UCHAR           **ptr,
625                        int              *size );
626
627/**
628 * \brief Set one single decoder parameter.
629 *
630 * \param self   AAC decoder handle.
631 * \param param  Parameter to be set.
632 * \param value  Parameter value.
633 * \return       Error code.
634 */
635LINKSPEC_H AAC_DECODER_ERROR
636aacDecoder_SetParam ( const HANDLE_AACDECODER  self,
637                      const AACDEC_PARAM       param,
638                      const INT                value );
639
640
641/**
642 * \brief              Get free bytes inside decoder internal buffer
643 * \param self    Handle of AAC decoder instance
644 * \param pFreeBytes Pointer to variable receving amount of free bytes inside decoder internal buffer
645 * \return             Error code
646 */
647LINKSPEC_H AAC_DECODER_ERROR
648aacDecoder_GetFreeBytes ( const HANDLE_AACDECODER  self,
649                                            UINT *pFreeBytes);
650
651/**
652 * \brief               Open an AAC decoder instance
653 * \param transportFmt  The transport type to be used
654 * \return              AAC decoder handle
655 */
656LINKSPEC_H HANDLE_AACDECODER
657aacDecoder_Open ( TRANSPORT_TYPE transportFmt, UINT nrOfLayers );
658
659/**
660 * \brief Explicitly configure the decoder by passing a raw AudioSpecificConfig (ASC) or a StreamMuxConfig (SMC),
661 *  contained in a binary buffer. This is required for MPEG-4 and Raw Packets file format bitstreams
662 *  as well as for LATM bitstreams with no in-band SMC. If the transport format is LATM with or without
663 *  LOAS, configuration is assumed to be an SMC, for all other file formats an ASC.
664 *
665 * \param self    AAC decoder handle.
666 * \param conf    Pointer to an unsigned char buffer containing the binary configuration buffer (either ASC or SMC).
667 * \param length  Length of the configuration buffer in bytes.
668 * \return        Error code.
669 */
670LINKSPEC_H AAC_DECODER_ERROR
671aacDecoder_ConfigRaw ( HANDLE_AACDECODER self,
672                       UCHAR            *conf[],
673                       const UINT        length[] );
674
675
676/**
677 * \brief Fill AAC decoder's internal input buffer with bitstream data from the external input buffer.
678 *  The function only copies such data as long as the decoder-internal input buffer is not full.
679 *  So it grabs whatever it can from pBuffer and returns information (bytesValid) so that at a
680 *  subsequent call of %aacDecoder_Fill(), the right position in pBuffer can be determined to
681 *  grab the next data.
682 *
683 * \param self        AAC decoder handle.
684 * \param pBuffer     Pointer to external input buffer.
685 * \param bufferSize  Size of external input buffer. This argument is required because decoder-internally
686 *                    we need the information to calculate the offset to pBuffer, where the next
687 *                    available data is, which is then fed into the decoder-internal buffer (as much
688 *                    as possible). Our example framework implementation fills the buffer at pBuffer
689 *                    again, once it contains no available valid bytes anymore (meaning bytesValid equal 0).
690 * \param bytesValid  Number of bitstream bytes in the external bitstream buffer that have not yet been
691 *                    copied into the decoder's internal bitstream buffer by calling this function.
692 *                    The value is updated according to the amount of newly copied bytes.
693 * \return            Error code.
694 */
695LINKSPEC_H AAC_DECODER_ERROR
696aacDecoder_Fill ( HANDLE_AACDECODER  self,
697                  UCHAR             *pBuffer[],
698                  const UINT         bufferSize[],
699                  UINT              *bytesValid );
700
701#define AACDEC_CONCEAL  1 /*!< Flag for aacDecoder_DecodeFrame(): Trigger the built-in error concealment module \
702                                 to generate a substitute signal for one lost frame. New input data will not be
703                                 considered. */
704#define AACDEC_FLUSH    2 /*!< Flag for aacDecoder_DecodeFrame(): Flush all filterbanks to get all delayed audio \
705                                 without having new input data. Thus new input data will not be considered.*/
706#define AACDEC_INTR     4 /*!< Flag for aacDecoder_DecodeFrame(): Signal an input bit stream data discontinuity. \
707                                 Resync any internals as necessary. */
708#define AACDEC_CLRHIST  8 /*!< Flag for aacDecoder_DecodeFrame(): Clear all signal delay lines and history buffers.\
709                                 CAUTION: This can cause discontinuities in the output signal. */
710
711/**
712 * \brief            Decode one audio frame
713 *
714 * \param self       AAC decoder handle.
715 * \param pTimeData  Pointer to external output buffer where the decoded PCM samples will be stored into.
716 * \param flags      Bit field with flags for the decoder: \n
717 *                   (flags & AACDEC_CONCEAL) == 1: Do concealment. \n
718 *                   (flags & AACDEC_FLUSH) == 2: Discard input data. Flush filter banks (output delayed audio). \n
719 *                   (flags & AACDEC_INTR) == 4: Input data is discontinuous. Resynchronize any internals as necessary.
720 * \return           Error code.
721 */
722LINKSPEC_H AAC_DECODER_ERROR
723aacDecoder_DecodeFrame ( HANDLE_AACDECODER  self,
724                         INT_PCM           *pTimeData,
725                         const INT          timeDataSize,
726                         const UINT         flags );
727
728/**
729 * \brief       De-allocate all resources of an AAC decoder instance.
730 *
731 * \param self  AAC decoder handle.
732 * \return      void
733 */
734LINKSPEC_H void aacDecoder_Close ( HANDLE_AACDECODER self );
735
736/**
737 * \brief       Get CStreamInfo handle from decoder.
738 *
739 * \param self  AAC decoder handle.
740 * \return      Reference to requested CStreamInfo.
741 */
742LINKSPEC_H CStreamInfo* aacDecoder_GetStreamInfo( HANDLE_AACDECODER self );
743
744/**
745 * \brief       Get decoder library info.
746 *
747 * \param info  Pointer to an allocated LIB_INFO structure.
748 * \return      0 on success
749 */
750LINKSPEC_H INT aacDecoder_GetLibInfo( LIB_INFO *info );
751
752
753#ifdef __cplusplus
754}
755#endif
756
757#endif /* AACDECODER_LIB_H */
758