1
2/* -----------------------------------------------------------------------------------------------------------
3Software License for The Fraunhofer FDK AAC Codec Library for Android
4
5� Copyright  1995 - 2013 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
6  All rights reserved.
7
8 1.    INTRODUCTION
9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12
13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16of the MPEG specifications.
17
18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20individually for the purpose of encoding or decoding bit streams in products that are compliant with
21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23software may already be covered under those patent licenses when it is used for those licensed purposes only.
24
25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27applications information and documentation.
28
292.    COPYRIGHT LICENSE
30
31Redistribution and use in source and binary forms, with or without modification, are permitted without
32payment of copyright license fees provided that you satisfy the following conditions:
33
34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35your modifications thereto in source code form.
36
37You must retain the complete text of this software license in the documentation and/or other materials
38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40modifications thereto to recipients of copies in binary form.
41
42The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43prior written permission.
44
45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46software or your modifications thereto.
47
48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49and the date of any change. For modified versions of the FDK AAC Codec, the term
50"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
51"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
52
533.    NO PATENT LICENSE
54
55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57respect to this software.
58
59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60by appropriate patent licenses.
61
624.    DISCLAIMER
63
64This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
65"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69or business interruption, however caused and on any theory of liability, whether in contract, strict
70liability, or tort (including negligence), arising in any way out of the use of this software, even if
71advised of the possibility of such damage.
72
735.    CONTACT INFORMATION
74
75Fraunhofer Institute for Integrated Circuits IIS
76Attention: Audio and Multimedia Departments - FDK AAC LL
77Am Wolfsmantel 33
7891058 Erlangen, Germany
79
80www.iis.fraunhofer.de/amm
81amm-info@iis.fraunhofer.de
82----------------------------------------------------------------------------------------------------------- */
83
84/*****************************  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 (see \ref CommandLineUsage). For any other bitstream formats that are
148usually applicable in streaming applications, the decoder itself will try to synchronize and parse the given
149bitstream fragment using the FDK transport library. Hence, for streaming applications (without file access)
150this step is not necessary.
151
152-# Call aacDecoder_Open() to open and retrieve a handle to a new AAC decoder instance.
153\dontinclude main.cpp
154\skipline aacDecoder_Open
155-# If out-of-band config data (Audio Specific Config (ASC) or Stream Mux Config (SMC)) is available, call
156aacDecoder_ConfigRaw() to pass it to the decoder and before the decoding process starts. If this data is
157not available in advance, the decoder will get it from the bitstream  and configure itself while decoding
158with aacDecoder_DecodeFrame().
159-# Begin decoding loop.
160\skipline do {
161-# Read data from bitstream file or stream into a client-supplied input buffer ("inBuffer" in main.cpp).
162If it is very small like just 4, aacDecoder_DecodeFrame() will
163repeatedly return ::AAC_DEC_NOT_ENOUGH_BITS until enough bits were fed by aacDecoder_Fill(). Only read data
164when this buffer has completely been processed and is then empty. For file-based input execute
165mpegFileRead_Read() or any other implementation with similar functionality.
166-# Call aacDecoder_Fill() to fill the decoder's internal bitstream input buffer with the client-supplied
167external bitstream input buffer.
168\skipline aacDecoder_Fill
169-# Call aacDecoder_DecodeFrame() which writes decoded PCM audio data to a client-supplied buffer. It is the
170client's responsibility to allocate a buffer which is large enough to hold this output data.
171\skipline aacDecoder_DecodeFrame
172If the bitstream's configuration (number of channels, sample rate, frame size) is not known in advance, you may
173call aacDecoder_GetStreamInfo() to retrieve a structure containing this information and then initialize an audio
174output device. In the example main.cpp, if the number of channels or the sample rate has changed since program
175start or since the previously decoded frame, the audio output device will be re-initialized. If WAVE file output
176is chosen, a new WAVE file for each new configuration will be created.
177\skipline aacDecoder_GetStreamInfo
178-# Repeat steps 5 to 7 until no data to decode is available anymore, or if an error occured.
179\skipline } while
180-# Call aacDecoder_Close() to de-allocate all AAC decoder and transport layer structures.
181\skipline aacDecoder_Close
182
183\section BufferSystem Buffer System
184
185There are three main buffers in an AAC decoder application. One external input buffer to hold bitstream
186data from file I/O or elsewhere, one decoder-internal input buffer, and one to hold the decoded output
187PCM sample data, whereas this output buffer may overlap with the external input buffer.
188
189The external input buffer is set in the example framework main.cpp and its size is defined by ::IN_BUF_SIZE.
190You may freely choose different sizes here. To feed the data to the decoder-internal input buffer, use the
191function aacDecoder_Fill(). This function returns important information about how many bytes in the
192external input buffer have not yet been copied into the internal input buffer (variable bytesValid).
193Once the external buffer has been fully copied, it can be re-filled again.
194In case you want to re-fill it when there are still unprocessed bytes (bytesValid is unequal 0), you
195would have to additionally perform a memcpy(), so that just means unnecessary computational overhead
196and therefore we recommend to re-fill the buffer only when bytesValid is 0.
197
198\image latex dec_buffer.png "Lifecycle of the external input buffer" width=9cm
199
200The size of the decoder-internal input buffer is set in tpdec_lib.h (see define ::TRANSPORTDEC_INBUF_SIZE).
201You may choose a smaller size under the following considerations:
202
203- each input channel requires 768 bytes
204- the whole buffer must be of size 2^n
205
206So for example a stereo decoder:
207
208\f[
209TRANSPORTDEC\_INBUF\_SIZE = 2 * 768 = 1536 => 2048
210\f]
211
212tpdec_lib.h and TRANSPORTDEC_INBUF_SIZE are not part of the decoder's library interface. Therefore
213only source-code clients may change this setting. If you received a library release, please ask us and
214we can change this in order to meet your memory requirements.
215
216\page OutputFormat Decoder audio output
217
218\section OutputFormatObtaining Obtaining channel mapping information
219
220The decoded audio output format is indicated by a set of variables of the CStreamInfo structure.
221While the members sampleRate, frameSize and numChannels might be quite self explaining,
222pChannelType and pChannelIndices might require some more detailed explanation.
223
224These two arrays indicate what is each output channel supposed to be. Both array have
225CStreamInfo::numChannels cells. Each cell of pChannelType indicates the channel type, described in
226the enum ::AUDIO_CHANNEL_TYPE defined in FDK_audio.h. The cells of pChannelIndices indicate the sub index
227among the channels starting with 0 among all channels of the same audio channel type.
228
229The indexing scheme is the same as for MPEG-2/4. Thus indices are counted upwards starting from the front
230direction (thus a center channel if any, will always be index 0). Then the indices count up, starting always
231with the left side, pairwise from front toward back. For detailed explanation, please refer to
232ISO/IEC 13818-7:2005(E), chapter 8.5.3.2.
233
234In case a Program Config is included in the audio configuration, the channel mapping described within
235it will be adopted.
236
237In case of MPEG-D Surround the channel mapping will follow the same criteria described in ISO/IEC 13818-7:2005(E),
238but adding corresponding top channels to the channel types front, side and back, in order to avoid any
239loss of information.
240
241\section OutputFormatChange Changing the audio output format
242
243The channel interleaving scheme and the actual channel order can be changed at runtime through the
244parameters ::AAC_PCM_OUTPUT_INTERLEAVED and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING. See the description of those
245parameters and the decoder library function aacDecoder_SetParam() for more detail.
246
247\section OutputFormatExample Channel mapping examples
248
249The following examples illustrate the location of individual audio samples in the audio buffer that
250is passed to aacDecoder_DecodeFrame() and the expected data in the CStreamInfo structure which can be obtained
251by calling aacDecoder_GetStreamInfo().
252
253\subsection ExamplesStereo Stereo
254
255In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 0 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
256a AAC-LC bit stream which has channelConfiguration = 2 in its audio specific config would lead
257to the following values in CStreamInfo:
258
259CStreamInfo::numChannels = 2
260
261CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT }
262
263CStreamInfo::pChannelIndices = { 0, 1 }
264
265Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 0, the audio channels will be located as contiguous blocks
266in the output buffer as follows:
267
268\verbatim
269  <left sample 0>  <left sample 1>  <left sample 2>  ... <left sample N>
270  <right sample 0> <right sample 1> <right sample 2> ... <right sample N>
271\endverbatim
272
273Where N equals to CStreamInfo::frameSize .
274
275\subsection ExamplesSurround Surround 5.1
276
277In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
278a AAC-LC bit stream which has channelConfiguration = 6 in its audio specific config, would lead
279to the following values in CStreamInfo:
280
281CStreamInfo::numChannels = 6
282
283CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT, ::ACT_FRONT, ::ACT_LFE, ::ACT_BACK, ::ACT_BACK }
284
285CStreamInfo::pChannelIndices = { 1, 2, 0, 0, 0, 1 }
286
287Since ::AAC_PCM_OUTPUT_CHANNEL_MAPPING is 1, WAV file channel ordering will be used. For a 5.1 channel
288scheme, thus the channels would be: front left, front right, center, LFE, surround left, surround right.
289Thus the third channel is the center channel, receiving the index 0. The other front channels are
290front left, front right being placed as first and second channels with indices 1 and 2 correspondingly.
291There is only one LFE, placed as the fourth channel and index 0. Finally both surround
292channels get the type definition ACT_BACK, and the indices 0 and 1.
293
294Since ::AAC_PCM_OUTPUT_INTERLEAVED is set to 1, the audio channels will be placed in the output buffer
295as follows:
296
297\verbatim
298<front left sample 0> <front right sample 0>
299<center sample 0> <LFE sample 0>
300<surround left sample 0> <surround right sample 0>
301
302<front left sample 1> <front right sample 1>
303<center sample 1> <LFE sample 1>
304<surround left sample 1> <surround right sample 1>
305
306...
307
308<front left sample N> <front right sample N>
309<center sample N> <LFE sample N>
310<surround left sample N> <surround right sample N>
311\endverbatim
312
313Where N equals to CStreamInfo::frameSize .
314
315\subsection ExamplesArib ARIB coding mode 2/1
316
317In case of ::AAC_PCM_OUTPUT_INTERLEAVED set to 1 and ::AAC_PCM_OUTPUT_CHANNEL_MAPPING set to 1,
318in 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,
319would lead to the following values in CStreamInfo:
320
321CStreamInfo::numChannels = 3
322
323CStreamInfo::pChannelType = { ::ACT_FRONT, ::ACT_FRONT,:: ACT_BACK }
324
325CStreamInfo::pChannelIndices = { 0, 1, 0 }
326
327The audio channels will be placed as follows in the audio output buffer:
328
329\verbatim
330<front left sample 0> <front right sample 0>  <mid surround sample 0>
331
332<front left sample 1> <front right sample 1> <mid surround sample 1>
333
334...
335
336<front left sample N> <front right sample N> <mid surround sample N>
337
338Where N equals to CStreamInfo::frameSize .
339
340\endverbatim
341
342*/
343
344#ifndef AACDECODER_LIB_H
345#define AACDECODER_LIB_H
346
347#include "machine_type.h"
348#include "FDK_audio.h"
349
350#include "genericStds.h"
351
352/**
353 * \brief  AAC decoder error codes.
354 */
355typedef enum {
356  AAC_DEC_OK                             = 0x0000,  /*!< No error occured. Output buffer is valid and error free. */
357  AAC_DEC_OUT_OF_MEMORY                  = 0x0002,  /*!< Heap returned NULL pointer. Output buffer is invalid. */
358  AAC_DEC_UNKNOWN                        = 0x0005,  /*!< Error condition is of unknown reason, or from a another module. Output buffer is invalid. */
359
360  /* Synchronization errors. Output buffer is invalid. */
361  aac_dec_sync_error_start               = 0x1000,
362  AAC_DEC_TRANSPORT_SYNC_ERROR           = 0x1001,  /*!< The transport decoder had syncronisation problems. Do not exit decoding. Just feed new
363                                                         bitstream data. */
364  AAC_DEC_NOT_ENOUGH_BITS                = 0x1002,  /*!< The input buffer ran out of bits. */
365  aac_dec_sync_error_end                 = 0x1FFF,
366
367  /* Initialization errors. Output buffer is invalid. */
368  aac_dec_init_error_start               = 0x2000,
369  AAC_DEC_INVALID_HANDLE                 = 0x2001,  /*!< The handle passed to the function call was invalid (NULL). */
370  AAC_DEC_UNSUPPORTED_AOT                = 0x2002,  /*!< The AOT found in the configuration is not supported. */
371  AAC_DEC_UNSUPPORTED_FORMAT             = 0x2003,  /*!< The bitstream format is not supported.  */
372  AAC_DEC_UNSUPPORTED_ER_FORMAT          = 0x2004,  /*!< The error resilience tool format is not supported. */
373  AAC_DEC_UNSUPPORTED_EPCONFIG           = 0x2005,  /*!< The error protection format is not supported. */
374  AAC_DEC_UNSUPPORTED_MULTILAYER         = 0x2006,  /*!< More than one layer for AAC scalable is not supported. */
375  AAC_DEC_UNSUPPORTED_CHANNELCONFIG      = 0x2007,  /*!< The channel configuration (either number or arrangement) is not supported. */
376  AAC_DEC_UNSUPPORTED_SAMPLINGRATE       = 0x2008,  /*!< The sample rate specified in the configuration is not supported. */
377  AAC_DEC_INVALID_SBR_CONFIG             = 0x2009,  /*!< The SBR configuration is not supported. */
378  AAC_DEC_SET_PARAM_FAIL                 = 0x200A,  /*!< The parameter could not be set. Either the value was out of range or the parameter does
379                                                         not exist. */
380  AAC_DEC_NEED_TO_RESTART                = 0x200B,  /*!< The decoder needs to be restarted, since the requiered configuration change cannot be
381                                                         performed. */
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_OUTPUT_CHANNELS                 = 0x0001,  /*!< Number of PCM output channels (if different from encoded audio channels, downmixing or
434                                                          upmixing is applied). \n
435                                                          -1: Disable up-/downmixing. The decoder output contains the same number of channels as the
436                                                              encoded bitstream. \n
437                                                           1: The decoder performs a mono matrix mix-down if the encoded audio channels are greater
438                                                              than one. Thus it ouputs always exact one channel. \n
439                                                           2: The decoder performs a stereo matrix mix-down if the encoded audio channels are greater
440                                                              than two. If the encoded audio channels are smaller than two the decoder duplicates the
441                                                              output. Thus it ouputs always exact two channels. \n */
442  AAC_PCM_DUAL_CHANNEL_OUTPUT_MODE        = 0x0002,  /*!< Defines how the decoder processes two channel signals:
443                                                          0: Leave both signals as they are (default).
444                                                          1: Create a dual mono output signal from channel 1.
445                                                          2: Create a dual mono output signal from channel 2.
446                                                          3: Create a dual mono output signal by mixing both channels (L' = R' = 0.5*Ch1 + 0.5*Ch2). */
447  AAC_PCM_OUTPUT_CHANNEL_MAPPING          = 0x0003,  /*!< Output buffer channel ordering. 0: MPEG PCE style order, 1: WAV file channel order (default). */
448
449  AAC_CONCEAL_METHOD                      = 0x0100,  /*!< Error concealment: Processing method. \n
450                                                          0: Spectral muting. \n
451                                                          1: Noise substitution (see ::CONCEAL_NOISE). \n
452                                                          2: Energy interpolation (adds additional signal delay of one frame, see ::CONCEAL_INTER). \n */
453
454  AAC_DRC_BOOST_FACTOR                    = 0x0200,  /*!< Dynamic Range Control: Scaling factor for boosting gain values.
455                                                          Defines how the boosting DRC factors (conveyed in the bitstream) will be applied to the
456                                                          decoded signal. The valid values range from 0 (don't apply boost factors) to 127 (fully
457                                                          apply all boosting factors). */
458  AAC_DRC_ATTENUATION_FACTOR              = 0x0201,  /*!< Dynamic Range Control: Scaling factor for attenuating gain values. Same as
459                                                          AAC_DRC_BOOST_FACTOR but for attenuating DRC factors. */
460  AAC_DRC_REFERENCE_LEVEL                 = 0x0202,  /*!< Dynamic Range Control: Target reference level. Defines the level below full-scale
461                                                          (quantized in steps of 0.25dB) to which the output audio signal will be normalized to by
462                                                          the DRC module. The valid values range from 0 (full-scale) to 127 (31.75 dB below
463                                                          full-scale). The value smaller than 0 switches off normalization. */
464  AAC_DRC_HEAVY_COMPRESSION               = 0x0203,  /*!< Dynamic Range Control: En-/Disable DVB specific heavy compression (aka RF mode).
465                                                          If set to 1, the decoder will apply the compression values from the DVB specific ancillary
466                                                          data field. At the same time the MPEG-4 Dynamic Range Control tool will be disabled. By
467                                                          default heavy compression is disabled. */
468
469  AAC_QMF_LOWPOWER                        = 0x0300,  /*!< Quadrature Mirror Filter (QMF) Bank processing mode. \n
470                                                          -1: Use internal default. Implies MPEG Surround partially complex accordingly. \n
471                                                           0: Use complex QMF data mode. \n
472                                                           1: Use real (low power) QMF data mode. \n */
473
474  AAC_MPEGS_ENABLE                        = 0x0500,  /*!< MPEG Surround: Allow/Disable decoding of MPS content. Available only for decoders with MPEG
475                                                          Surround support. */
476
477  AAC_TPDEC_CLEAR_BUFFER                  = 0x0603   /*!< Clear internal bit stream buffer of transport layers. The decoder will start decoding
478                                                          at new data passed after this event and any previous data is discarded. */
479
480} AACDEC_PARAM;
481
482/**
483 * \brief This structure gives information about the currently decoded audio data.
484 *        All fields are read-only.
485 */
486typedef struct
487{
488  /* These three members are the only really relevant ones for the user.                                                           */
489  INT               sampleRate;          /*!< The samplerate in Hz of the fully decoded PCM audio signal (after SBR processing).   */
490  INT               frameSize;           /*!< The frame size of the decoded PCM audio signal. \n
491                                              1024 or 960 for AAC-LC \n
492                                              2048 or 1920 for HE-AAC (v2) \n
493                                              512 or 480 for AAC-LD and AAC-ELD                                                    */
494  INT               numChannels;         /*!< The number of output audio channels in the decoded and interleaved PCM audio signal. */
495  AUDIO_CHANNEL_TYPE *pChannelType;       /*!< Audio channel type of each output audio channel.           */
496  UCHAR             *pChannelIndices;     /*!< Audio channel index for each output audio channel.
497                                               See ISO/IEC 13818-7:2005(E), 8.5.3.2 Explicit channel mapping using a program_config_element() */
498  /* Decoder internal members. */
499  INT               aacSampleRate;       /*!< sampling rate in Hz without SBR (from configuration info).                           */
500  INT               profile;             /*!< MPEG-2 profile (from file header) (-1: not applicable (e. g. MPEG-4)).               */
501  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). */
502  INT               channelConfig;       /*!< Channel configuration (0: PCE defined, 1: mono, 2: stereo, ...                       */
503  INT               bitRate;             /*!< Instantaneous bit rate.                   */
504  INT               aacSamplesPerFrame;  /*!< Samples per frame for the AAC core (from ASC). \n
505                                              1024 or 960 for AAC-LC \n
506                                              512 or 480 for AAC-LD and AAC-ELD         */
507  INT               aacNumChannels;      /*!< The number of audio channels after AAC core processing (before PS or MPS processing).
508                                              CAUTION: This are not the final number of output channels! */
509  AUDIO_OBJECT_TYPE extAot;              /*!< Extension Audio Object Type (from ASC)   */
510  INT               extSamplingRate;     /*!< Extension sampling rate in Hz (from ASC) */
511
512  UINT              flags;               /*!< Copy if internal flags. Only to be written by the decoder, and only to be read externally. */
513
514  SCHAR             epConfig;            /*!< epConfig level (from ASC): only level 0 supported, -1 means no ER (e. g. AOT=2, MPEG-2 AAC, etc.)  */
515
516  /* Statistics */
517  INT               numLostAccessUnits;  /*!< This integer will reflect the estimated amount of lost access units in case aacDecoder_DecodeFrame()
518                                              returns AAC_DEC_TRANSPORT_SYNC_ERROR. It will be < 0 if the estimation failed. */
519
520  UINT              numTotalBytes;       /*!< This is the number of total bytes that have passed through the decoder. */
521  UINT              numBadBytes;         /*!< This is the number of total bytes that were considered with errors from numTotalBytes. */
522  UINT              numTotalAccessUnits; /*!< This is the number of total access units that have passed through the decoder. */
523  UINT              numBadAccessUnits;   /*!< This is the number of total access units that were considered with errors from numTotalBytes. */
524
525} CStreamInfo;
526
527
528typedef struct AAC_DECODER_INSTANCE *HANDLE_AACDECODER;
529
530#ifdef __cplusplus
531extern "C"
532{
533#endif
534
535/**
536 * \brief Initialize ancillary data buffer.
537 *
538 * \param self    AAC decoder handle.
539 * \param buffer  Pointer to (external) ancillary data buffer.
540 * \param size    Size of the buffer pointed to by buffer.
541 * \return        Error code.
542 */
543LINKSPEC_H AAC_DECODER_ERROR
544aacDecoder_AncDataInit ( HANDLE_AACDECODER self,
545                         UCHAR            *buffer,
546                         int               size );
547
548/**
549 * \brief Get one ancillary data element.
550 *
551 * \param self   AAC decoder handle.
552 * \param index  Index of the ancillary data element to get.
553 * \param ptr    Pointer to a buffer receiving a pointer to the requested ancillary data element.
554 * \param size   Pointer to a buffer receiving the length of the requested ancillary data element.
555 * \return       Error code.
556 */
557LINKSPEC_H AAC_DECODER_ERROR
558aacDecoder_AncDataGet ( HANDLE_AACDECODER self,
559                        int               index,
560                        UCHAR           **ptr,
561                        int              *size );
562
563/**
564 * \brief Set one single decoder parameter.
565 *
566 * \param self   AAC decoder handle.
567 * \param param  Parameter to be set.
568 * \param value  Parameter value.
569 * \return       Error code.
570 */
571LINKSPEC_H AAC_DECODER_ERROR
572aacDecoder_SetParam ( const HANDLE_AACDECODER  self,
573                      const AACDEC_PARAM       param,
574                      const INT                value );
575
576
577/**
578 * \brief              Get free bytes inside decoder internal buffer
579 * \param self    Handle of AAC decoder instance
580 * \param pFreeBytes Pointer to variable receving amount of free bytes inside decoder internal buffer
581 * \return             Error code
582 */
583LINKSPEC_H AAC_DECODER_ERROR
584aacDecoder_GetFreeBytes ( const HANDLE_AACDECODER  self,
585                                            UINT *pFreeBytes);
586
587/**
588 * \brief               Open an AAC decoder instance
589 * \param transportFmt  The transport type to be used
590 * \return              AAC decoder handle
591 */
592LINKSPEC_H HANDLE_AACDECODER
593aacDecoder_Open ( TRANSPORT_TYPE transportFmt, UINT nrOfLayers );
594
595/**
596 * \brief Explicitly configure the decoder by passing a raw AudioSpecificConfig (ASC) or a StreamMuxConfig (SMC),
597 *  contained in a binary buffer. This is required for MPEG-4 and Raw Packets file format bitstreams
598 *  as well as for LATM bitstreams with no in-band SMC. If the transport format is LATM with or without
599 *  LOAS, configuration is assumed to be an SMC, for all other file formats an ASC.
600 *
601 * \param self    AAC decoder handle.
602 * \param conf    Pointer to an unsigned char buffer containing the binary configuration buffer (either ASC or SMC).
603 * \param length  Length of the configuration buffer in bytes.
604 * \return        Error code.
605 */
606LINKSPEC_H AAC_DECODER_ERROR
607aacDecoder_ConfigRaw ( HANDLE_AACDECODER self,
608                       UCHAR            *conf[],
609                       const UINT        length[] );
610
611
612/**
613 * \brief Fill AAC decoder's internal input buffer with bitstream data from the external input buffer.
614 *  The function only copies such data as long as the decoder-internal input buffer is not full.
615 *  So it grabs whatever it can from pBuffer and returns information (bytesValid) so that at a
616 *  subsequent call of %aacDecoder_Fill(), the right position in pBuffer can be determined to
617 *  grab the next data.
618 *
619 * \param self        AAC decoder handle.
620 * \param pBuffer     Pointer to external input buffer.
621 * \param bufferSize  Size of external input buffer. This argument is required because decoder-internally
622 *                    we need the information to calculate the offset to pBuffer, where the next
623 *                    available data is, which is then fed into the decoder-internal buffer (as much
624 *                    as possible). Our example framework implementation fills the buffer at pBuffer
625 *                    again, once it contains no available valid bytes anymore (meaning bytesValid equal 0).
626 * \param bytesValid  Number of bitstream bytes in the external bitstream buffer that have not yet been
627 *                    copied into the decoder's internal bitstream buffer by calling this function.
628 *                    The value is updated according to the amount of newly copied bytes.
629 * \return            Error code.
630 */
631LINKSPEC_H AAC_DECODER_ERROR
632aacDecoder_Fill ( HANDLE_AACDECODER  self,
633                  UCHAR             *pBuffer[],
634                  const UINT         bufferSize[],
635                  UINT              *bytesValid );
636
637#define AACDEC_CONCEAL  1 /*!< Flag for aacDecoder_DecodeFrame(): do not consider new input data. Do concealment. */
638#define AACDEC_FLUSH    2 /*!< Flag for aacDecoder_DecodeFrame(): Do not consider new input data. Flush filterbanks (output delayed audio). */
639#define AACDEC_INTR     4 /*!< Flag for aacDecoder_DecodeFrame(): Signal an input bit stream data discontinuity. Resync any internals as necessary. */
640#define AACDEC_CLRHIST  8 /*!< Flag for aacDecoder_DecodeFrame(): Clear all signal delay lines and history buffers.
641                               Caution: This can cause discontinuities in the output signal. */
642
643/**
644 * \brief            Decode one audio frame
645 *
646 * \param self       AAC decoder handle.
647 * \param pTimeData  Pointer to external output buffer where the decoded PCM samples will be stored into.
648 * \param flags      Bit field with flags for the decoder: \n
649 *                   (flags & AACDEC_CONCEAL) == 1: Do concealment. \n
650 *                   (flags & AACDEC_FLUSH) == 2: Discard input data. Flush filter banks (output delayed audio). \n
651 *                   (flags & AACDEC_INTR) == 4: Input data is discontinuous. Resynchronize any internals as necessary.
652 * \return           Error code.
653 */
654LINKSPEC_H AAC_DECODER_ERROR
655aacDecoder_DecodeFrame ( HANDLE_AACDECODER  self,
656                         INT_PCM           *pTimeData,
657                         const INT          timeDataSize,
658                         const UINT         flags );
659
660/**
661 * \brief       De-allocate all resources of an AAC decoder instance.
662 *
663 * \param self  AAC decoder handle.
664 * \return      void
665 */
666LINKSPEC_H void aacDecoder_Close ( HANDLE_AACDECODER self );
667
668/**
669 * \brief       Get CStreamInfo handle from decoder.
670 *
671 * \param self  AAC decoder handle.
672 * \return      Reference to requested CStreamInfo.
673 */
674LINKSPEC_H CStreamInfo* aacDecoder_GetStreamInfo( HANDLE_AACDECODER self );
675
676/**
677 * \brief       Get decoder library info.
678 *
679 * \param info  Pointer to an allocated LIB_INFO structure.
680 * \return      0 on success
681 */
682LINKSPEC_H INT aacDecoder_GetLibInfo( LIB_INFO *info );
683
684
685#ifdef __cplusplus
686}
687#endif
688
689#endif /* AACDECODER_LIB_H */
690