1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4 © Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5 Forschung e.V. All rights reserved.
6
7 1. INTRODUCTION
8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
11 a wide variety of Android devices.
12
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14 general perceptual audio codecs. AAC-ELD is considered the best-performing
15 full-bandwidth communications codec by independent studies and is widely
16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17 specifications.
18
19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
20 those of Fraunhofer) may be obtained through Via Licensing
21 (www.vialicensing.com) or through the respective patent owners individually for
22 the purpose of encoding or decoding bit streams in products that are compliant
23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24 Android devices already license these patent claims through Via Licensing or
25 directly from the patent owners, and therefore FDK AAC Codec software may
26 already be covered under those patent licenses when it is used for those
27 licensed purposes only.
28
29 Commercially-licensed AAC software libraries, including floating-point versions
30 with enhanced sound quality, are also available from Fraunhofer. Users are
31 encouraged to check the Fraunhofer website for additional applications
32 information and documentation.
33
34 2. COPYRIGHT LICENSE
35
36 Redistribution and use in source and binary forms, with or without modification,
37 are permitted without payment of copyright license fees provided that you
38 satisfy the following conditions:
39
40 You must retain the complete text of this software license in redistributions of
41 the FDK AAC Codec or your modifications thereto in source code form.
42
43 You must retain the complete text of this software license in the documentation
44 and/or other materials provided with redistributions of the FDK AAC Codec or
45 your modifications thereto in binary form. You must make available free of
46 charge copies of the complete source code of the FDK AAC Codec and your
47 modifications thereto to recipients of copies in binary form.
48
49 The name of Fraunhofer may not be used to endorse or promote products derived
50 from this library without prior written permission.
51
52 You may not charge copyright license fees for anyone to use, copy or distribute
53 the FDK AAC Codec software or your modifications thereto.
54
55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
56 that you changed the software and the date of any change. For modified versions
57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59 AAC Codec Library for Android."
60
61 3. NO PATENT LICENSE
62
63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65 Fraunhofer provides no warranty of patent non-infringement with respect to this
66 software.
67
68 You may use this FDK AAC Codec software or modifications thereto only for
69 purposes that are authorized by appropriate patent licenses.
70
71 4. DISCLAIMER
72
73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75 including but not limited to the implied warranties of merchantability and
76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78 or consequential damages, including but not limited to procurement of substitute
79 goods or services; loss of use, data, or profits, or business interruption,
80 however caused and on any theory of liability, whether in contract, strict
81 liability, or tort (including negligence), arising in any way out of the use of
82 this software, even if advised of the possibility of such damage.
83
84 5. CONTACT INFORMATION
85
86 Fraunhofer Institute for Integrated Circuits IIS
87 Attention: Audio and Multimedia Departments - FDK AAC LL
88 Am Wolfsmantel 33
89 91058 Erlangen, Germany
90
91 www.iis.fraunhofer.de/amm
92 amm-info@iis.fraunhofer.de
93 ----------------------------------------------------------------------------- */
94
95 /******************* MPEG transport format decoder library *********************
96
97 Author(s): Josef Hoepfl
98
99 Description: ADTS interface
100
101 *******************************************************************************/
102
103 #include "tpdec_adts.h"
104
105 #include "FDK_bitstream.h"
106
adtsRead_CrcInit(HANDLE_ADTS pAdts)107 void adtsRead_CrcInit(
108 HANDLE_ADTS pAdts) /*!< pointer to adts crc info stucture */
109 {
110 FDKcrcInit(&pAdts->crcInfo, 0x8005, 0xFFFF, 16);
111 }
112
adtsRead_CrcStartReg(HANDLE_ADTS pAdts,HANDLE_FDK_BITSTREAM hBs,int mBits)113 int adtsRead_CrcStartReg(
114 HANDLE_ADTS pAdts, /*!< pointer to adts stucture */
115 HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
116 int mBits /*!< number of bits in crc region */
117 ) {
118 if (pAdts->bs.protection_absent) {
119 return 0;
120 }
121
122 return (FDKcrcStartReg(&pAdts->crcInfo, hBs, mBits));
123 }
124
adtsRead_CrcEndReg(HANDLE_ADTS pAdts,HANDLE_FDK_BITSTREAM hBs,int reg)125 void adtsRead_CrcEndReg(
126 HANDLE_ADTS pAdts, /*!< pointer to adts crc info stucture */
127 HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
128 int reg /*!< crc region */
129 ) {
130 if (pAdts->bs.protection_absent == 0) {
131 FDKcrcEndReg(&pAdts->crcInfo, hBs, reg);
132 }
133 }
134
adtsRead_CrcCheck(HANDLE_ADTS pAdts)135 TRANSPORTDEC_ERROR adtsRead_CrcCheck(HANDLE_ADTS pAdts) {
136 TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;
137 USHORT crc;
138
139 if (pAdts->bs.protection_absent) return TRANSPORTDEC_OK;
140
141 crc = FDKcrcGetCRC(&pAdts->crcInfo);
142 if (crc != pAdts->crcReadValue) {
143 return (TRANSPORTDEC_CRC_ERROR);
144 }
145
146 return (ErrorStatus);
147 }
148
149 #define Adts_Length_SyncWord 12
150 #define Adts_Length_Id 1
151 #define Adts_Length_Layer 2
152 #define Adts_Length_ProtectionAbsent 1
153 #define Adts_Length_Profile 2
154 #define Adts_Length_SamplingFrequencyIndex 4
155 #define Adts_Length_PrivateBit 1
156 #define Adts_Length_ChannelConfiguration 3
157 #define Adts_Length_OriginalCopy 1
158 #define Adts_Length_Home 1
159 #define Adts_Length_CopyrightIdentificationBit 1
160 #define Adts_Length_CopyrightIdentificationStart 1
161 #define Adts_Length_FrameLength 13
162 #define Adts_Length_BufferFullness 11
163 #define Adts_Length_NumberOfRawDataBlocksInFrame 2
164 #define Adts_Length_CrcCheck 16
165
adtsRead_DecodeHeader(HANDLE_ADTS pAdts,CSAudioSpecificConfig * pAsc,HANDLE_FDK_BITSTREAM hBs,const INT ignoreBufferFullness)166 TRANSPORTDEC_ERROR adtsRead_DecodeHeader(HANDLE_ADTS pAdts,
167 CSAudioSpecificConfig *pAsc,
168 HANDLE_FDK_BITSTREAM hBs,
169 const INT ignoreBufferFullness) {
170 INT crcReg;
171
172 INT valBits;
173 INT cmp_buffer_fullness;
174 int i, adtsHeaderLength;
175
176 STRUCT_ADTS_BS bs;
177
178 CProgramConfig oldPce;
179 /* Store the old PCE temporarily. Maybe we'll need it later if we
180 have channelConfig=0 and no PCE in this frame. */
181 FDKmemcpy(&oldPce, &pAsc->m_progrConfigElement, sizeof(CProgramConfig));
182
183 valBits = FDKgetValidBits(hBs);
184
185 /* adts_fixed_header */
186 bs.mpeg_id = FDKreadBits(hBs, Adts_Length_Id);
187 bs.layer = FDKreadBits(hBs, Adts_Length_Layer);
188 bs.protection_absent = FDKreadBits(hBs, Adts_Length_ProtectionAbsent);
189 bs.profile = FDKreadBits(hBs, Adts_Length_Profile);
190 bs.sample_freq_index = FDKreadBits(hBs, Adts_Length_SamplingFrequencyIndex);
191 bs.private_bit = FDKreadBits(hBs, Adts_Length_PrivateBit);
192 bs.channel_config = FDKreadBits(hBs, Adts_Length_ChannelConfiguration);
193 bs.original = FDKreadBits(hBs, Adts_Length_OriginalCopy);
194 bs.home = FDKreadBits(hBs, Adts_Length_Home);
195
196 /* adts_variable_header */
197 bs.copyright_id = FDKreadBits(hBs, Adts_Length_CopyrightIdentificationBit);
198 bs.copyright_start =
199 FDKreadBits(hBs, Adts_Length_CopyrightIdentificationStart);
200 bs.frame_length = FDKreadBits(hBs, Adts_Length_FrameLength);
201 bs.adts_fullness = FDKreadBits(hBs, Adts_Length_BufferFullness);
202 bs.num_raw_blocks =
203 FDKreadBits(hBs, Adts_Length_NumberOfRawDataBlocksInFrame);
204 bs.num_pce_bits = 0;
205
206 adtsHeaderLength = ADTS_HEADERLENGTH;
207
208 if (!bs.protection_absent) {
209 FDKcrcReset(&pAdts->crcInfo);
210 FDKpushBack(hBs, 56); /* complete fixed and variable header! */
211 crcReg = FDKcrcStartReg(&pAdts->crcInfo, hBs, 0);
212 FDKpushFor(hBs, 56);
213 }
214
215 if (!bs.protection_absent && bs.num_raw_blocks > 0) {
216 for (i = 0; i < bs.num_raw_blocks; i++) {
217 pAdts->rawDataBlockDist[i] = (USHORT)FDKreadBits(hBs, 16);
218 adtsHeaderLength += 16;
219 }
220 /* Change raw data blocks to delta values */
221 pAdts->rawDataBlockDist[bs.num_raw_blocks] =
222 bs.frame_length - 7 - bs.num_raw_blocks * 2 - 2;
223 for (i = bs.num_raw_blocks; i > 0; i--) {
224 pAdts->rawDataBlockDist[i] -= pAdts->rawDataBlockDist[i - 1];
225 }
226 }
227
228 /* adts_error_check */
229 if (!bs.protection_absent) {
230 USHORT crc_check;
231
232 FDKcrcEndReg(&pAdts->crcInfo, hBs, crcReg);
233 crc_check = FDKreadBits(hBs, Adts_Length_CrcCheck);
234 adtsHeaderLength += Adts_Length_CrcCheck;
235
236 pAdts->crcReadValue = crc_check;
237 /* Check header CRC in case of multiple raw data blocks */
238 if (bs.num_raw_blocks > 0) {
239 if (pAdts->crcReadValue != FDKcrcGetCRC(&pAdts->crcInfo)) {
240 return TRANSPORTDEC_CRC_ERROR;
241 }
242 /* Reset CRC for the upcoming raw_data_block() */
243 FDKcrcReset(&pAdts->crcInfo);
244 }
245 }
246
247 /* check if valid header */
248 if ((bs.layer != 0) || // we only support MPEG ADTS
249 (bs.sample_freq_index >= 13) // we only support 96kHz - 7350kHz
250 ) {
251 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
252 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
253 }
254
255 /* special treatment of id-bit */
256 if ((bs.mpeg_id == 0) && (pAdts->decoderCanDoMpeg4 == 0)) {
257 /* MPEG-2 decoder cannot play MPEG-4 bitstreams */
258
259 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
260 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
261 }
262
263 if (!ignoreBufferFullness) {
264 cmp_buffer_fullness =
265 bs.frame_length * 8 +
266 bs.adts_fullness * 32 * getNumberOfEffectiveChannels(bs.channel_config);
267
268 /* Evaluate buffer fullness */
269 if (bs.adts_fullness != 0x7FF) {
270 if (pAdts->BufferFullnesStartFlag) {
271 if (valBits < cmp_buffer_fullness) {
272 /* Condition for start of decoding is not fulfilled */
273
274 /* The current frame will not be decoded */
275 FDKpushBack(hBs, adtsHeaderLength);
276
277 if ((cmp_buffer_fullness + adtsHeaderLength) >
278 (((8192 * 4) << 3) - 7)) {
279 return TRANSPORTDEC_SYNC_ERROR;
280 } else {
281 return TRANSPORTDEC_NOT_ENOUGH_BITS;
282 }
283 } else {
284 pAdts->BufferFullnesStartFlag = 0;
285 }
286 }
287 }
288 }
289
290 /* Get info from ADTS header */
291 AudioSpecificConfig_Init(pAsc);
292 pAsc->m_aot = (AUDIO_OBJECT_TYPE)(bs.profile + 1);
293 pAsc->m_samplingFrequencyIndex = bs.sample_freq_index;
294 pAsc->m_samplingFrequency = SamplingRateTable[bs.sample_freq_index];
295 pAsc->m_channelConfiguration = bs.channel_config;
296 pAsc->m_samplesPerFrame = 1024;
297
298 if (bs.channel_config == 0) {
299 int pceBits = 0;
300 UINT alignAnchor = FDKgetValidBits(hBs);
301
302 if (FDKreadBits(hBs, 3) == ID_PCE) {
303 /* Got luck! Parse the PCE */
304 crcReg = adtsRead_CrcStartReg(pAdts, hBs, 0);
305
306 CProgramConfig_Read(&pAsc->m_progrConfigElement, hBs, alignAnchor);
307
308 adtsRead_CrcEndReg(pAdts, hBs, crcReg);
309 pceBits = alignAnchor - FDKgetValidBits(hBs);
310 /* store the number of PCE bits */
311 bs.num_pce_bits = pceBits;
312 } else {
313 /* No PCE in this frame! Push back the ID tag bits. */
314 FDKpushBack(hBs, 3);
315
316 /* Encoders do not have to write a PCE in each frame.
317 So if we already have a valid PCE we have to use it. */
318 if (oldPce.isValid &&
319 (bs.sample_freq_index ==
320 pAdts->bs.sample_freq_index) /* we could compare the complete fixed
321 header (bytes) here! */
322 && (bs.channel_config == pAdts->bs.channel_config) /* == 0 */
323 &&
324 (bs.mpeg_id ==
325 pAdts->bs.mpeg_id)) { /* Restore previous PCE which is still valid */
326 FDKmemcpy(&pAsc->m_progrConfigElement, &oldPce, sizeof(CProgramConfig));
327 } else if (bs.mpeg_id == 0) {
328 /* If not it seems that we have a implicit channel configuration.
329 This mode is not allowed in the context of ISO/IEC 14496-3.
330 Skip this frame and try the next one. */
331 FDKpushFor(hBs, (bs.frame_length << 3) - adtsHeaderLength - 3);
332 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
333 }
334 /* else {
335 ISO/IEC 13818-7 implicit channel mapping is allowed.
336 So just open the box of chocolates to see what we got.
337 } */
338 }
339 }
340
341 /* Copy bit stream data struct to persistent memory now, once we passed all
342 * sanity checks above. */
343 FDKmemcpy(&pAdts->bs, &bs, sizeof(STRUCT_ADTS_BS));
344
345 return TRANSPORTDEC_OK;
346 }
347
adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts,INT blockNum)348 int adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts, INT blockNum) {
349 int length;
350
351 if (pAdts->bs.num_raw_blocks == 0) {
352 length =
353 (pAdts->bs.frame_length - 7)
354 << 3; /* aac_frame_length subtracted by the header size (7 bytes). */
355 if (pAdts->bs.protection_absent == 0)
356 length -= 16; /* substract 16 bit CRC */
357 } else {
358 if (pAdts->bs.protection_absent) {
359 length = -1; /* raw data block length is unknown */
360 } else {
361 if (blockNum < 0 || blockNum > 3) {
362 length = -1;
363 } else {
364 length = (pAdts->rawDataBlockDist[blockNum] << 3) - 16;
365 }
366 }
367 }
368 if (blockNum == 0 && length > 0) {
369 length -= pAdts->bs.num_pce_bits;
370 }
371 return length;
372 }
373