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) + ADTS_SYNCLENGTH;
184
185 if (valBits < ADTS_HEADERLENGTH) {
186 return TRANSPORTDEC_NOT_ENOUGH_BITS;
187 }
188
189 /* adts_fixed_header */
190 bs.mpeg_id = FDKreadBits(hBs, Adts_Length_Id);
191 bs.layer = FDKreadBits(hBs, Adts_Length_Layer);
192 bs.protection_absent = FDKreadBits(hBs, Adts_Length_ProtectionAbsent);
193 bs.profile = FDKreadBits(hBs, Adts_Length_Profile);
194 bs.sample_freq_index = FDKreadBits(hBs, Adts_Length_SamplingFrequencyIndex);
195 bs.private_bit = FDKreadBits(hBs, Adts_Length_PrivateBit);
196 bs.channel_config = FDKreadBits(hBs, Adts_Length_ChannelConfiguration);
197 bs.original = FDKreadBits(hBs, Adts_Length_OriginalCopy);
198 bs.home = FDKreadBits(hBs, Adts_Length_Home);
199
200 /* adts_variable_header */
201 bs.copyright_id = FDKreadBits(hBs, Adts_Length_CopyrightIdentificationBit);
202 bs.copyright_start =
203 FDKreadBits(hBs, Adts_Length_CopyrightIdentificationStart);
204 bs.frame_length = FDKreadBits(hBs, Adts_Length_FrameLength);
205 bs.adts_fullness = FDKreadBits(hBs, Adts_Length_BufferFullness);
206 bs.num_raw_blocks =
207 FDKreadBits(hBs, Adts_Length_NumberOfRawDataBlocksInFrame);
208 bs.num_pce_bits = 0;
209
210 adtsHeaderLength = ADTS_HEADERLENGTH;
211
212 if (valBits < bs.frame_length * 8) {
213 goto bail;
214 }
215
216 if (!bs.protection_absent) {
217 FDKcrcReset(&pAdts->crcInfo);
218 FDKpushBack(hBs, 56); /* complete fixed and variable header! */
219 crcReg = FDKcrcStartReg(&pAdts->crcInfo, hBs, 0);
220 FDKpushFor(hBs, 56);
221 }
222
223 if (!bs.protection_absent && bs.num_raw_blocks > 0) {
224 if ((INT)FDKgetValidBits(hBs) < bs.num_raw_blocks * 16) {
225 goto bail;
226 }
227 for (i = 0; i < bs.num_raw_blocks; i++) {
228 pAdts->rawDataBlockDist[i] = (USHORT)FDKreadBits(hBs, 16);
229 adtsHeaderLength += 16;
230 }
231 /* Change raw data blocks to delta values */
232 pAdts->rawDataBlockDist[bs.num_raw_blocks] =
233 bs.frame_length - 7 - bs.num_raw_blocks * 2 - 2;
234 for (i = bs.num_raw_blocks; i > 0; i--) {
235 pAdts->rawDataBlockDist[i] -= pAdts->rawDataBlockDist[i - 1];
236 }
237 }
238
239 /* adts_error_check */
240 if (!bs.protection_absent) {
241 USHORT crc_check;
242
243 FDKcrcEndReg(&pAdts->crcInfo, hBs, crcReg);
244
245 if ((INT)FDKgetValidBits(hBs) < Adts_Length_CrcCheck) {
246 goto bail;
247 }
248
249 crc_check = FDKreadBits(hBs, Adts_Length_CrcCheck);
250 adtsHeaderLength += Adts_Length_CrcCheck;
251
252 pAdts->crcReadValue = crc_check;
253 /* Check header CRC in case of multiple raw data blocks */
254 if (bs.num_raw_blocks > 0) {
255 if (pAdts->crcReadValue != FDKcrcGetCRC(&pAdts->crcInfo)) {
256 return TRANSPORTDEC_CRC_ERROR;
257 }
258 /* Reset CRC for the upcoming raw_data_block() */
259 FDKcrcReset(&pAdts->crcInfo);
260 }
261 }
262
263 /* check if valid header */
264 if ((bs.layer != 0) || // we only support MPEG ADTS
265 (bs.sample_freq_index >= 13) // we only support 96kHz - 7350kHz
266 ) {
267 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
268 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
269 }
270
271 /* special treatment of id-bit */
272 if ((bs.mpeg_id == 0) && (pAdts->decoderCanDoMpeg4 == 0)) {
273 /* MPEG-2 decoder cannot play MPEG-4 bitstreams */
274
275 FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
276 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
277 }
278
279 if (!ignoreBufferFullness) {
280 cmp_buffer_fullness =
281 bs.frame_length * 8 +
282 bs.adts_fullness * 32 * getNumberOfEffectiveChannels(bs.channel_config);
283
284 /* Evaluate buffer fullness */
285 if (bs.adts_fullness != 0x7FF) {
286 if (pAdts->BufferFullnesStartFlag) {
287 if (valBits < cmp_buffer_fullness) {
288 /* Condition for start of decoding is not fulfilled */
289
290 /* The current frame will not be decoded */
291 FDKpushBack(hBs, adtsHeaderLength);
292
293 if ((cmp_buffer_fullness + adtsHeaderLength) >
294 (((8192 * 4) << 3) - 7)) {
295 return TRANSPORTDEC_SYNC_ERROR;
296 } else {
297 return TRANSPORTDEC_NOT_ENOUGH_BITS;
298 }
299 } else {
300 pAdts->BufferFullnesStartFlag = 0;
301 }
302 }
303 }
304 }
305
306 /* Get info from ADTS header */
307 AudioSpecificConfig_Init(pAsc);
308 pAsc->m_aot = (AUDIO_OBJECT_TYPE)(bs.profile + 1);
309 pAsc->m_samplingFrequencyIndex = bs.sample_freq_index;
310 pAsc->m_samplingFrequency = SamplingRateTable[bs.sample_freq_index];
311 pAsc->m_channelConfiguration = bs.channel_config;
312 pAsc->m_samplesPerFrame = 1024;
313
314 if (bs.channel_config == 0) {
315 int pceBits = 0;
316 UINT alignAnchor = FDKgetValidBits(hBs);
317
318 if (FDKreadBits(hBs, 3) == ID_PCE) {
319 /* Got luck! Parse the PCE */
320 crcReg = adtsRead_CrcStartReg(pAdts, hBs, 0);
321
322 CProgramConfig_Read(&pAsc->m_progrConfigElement, hBs, alignAnchor);
323
324 adtsRead_CrcEndReg(pAdts, hBs, crcReg);
325 pceBits = alignAnchor - FDKgetValidBits(hBs);
326 /* store the number of PCE bits */
327 bs.num_pce_bits = pceBits;
328 } else {
329 /* No PCE in this frame! Push back the ID tag bits. */
330 FDKpushBack(hBs, 3);
331
332 /* Encoders do not have to write a PCE in each frame.
333 So if we already have a valid PCE we have to use it. */
334 if (oldPce.isValid &&
335 (bs.sample_freq_index ==
336 pAdts->bs.sample_freq_index) /* we could compare the complete fixed
337 header (bytes) here! */
338 && (bs.channel_config == pAdts->bs.channel_config) /* == 0 */
339 &&
340 (bs.mpeg_id ==
341 pAdts->bs.mpeg_id)) { /* Restore previous PCE which is still valid */
342 FDKmemcpy(&pAsc->m_progrConfigElement, &oldPce, sizeof(CProgramConfig));
343 } else if (bs.mpeg_id == 0) {
344 /* If not it seems that we have a implicit channel configuration.
345 This mode is not allowed in the context of ISO/IEC 14496-3.
346 Skip this frame and try the next one. */
347 FDKpushFor(hBs, (bs.frame_length << 3) - adtsHeaderLength - 3);
348 return TRANSPORTDEC_UNSUPPORTED_FORMAT;
349 }
350 /* else {
351 ISO/IEC 13818-7 implicit channel mapping is allowed.
352 So just open the box of chocolates to see what we got.
353 } */
354 }
355 }
356
357 /* Copy bit stream data struct to persistent memory now, once we passed all
358 * sanity checks above. */
359 FDKmemcpy(&pAdts->bs, &bs, sizeof(STRUCT_ADTS_BS));
360
361 return TRANSPORTDEC_OK;
362
363 bail:
364 FDKpushBack(hBs, adtsHeaderLength);
365 return TRANSPORTDEC_NOT_ENOUGH_BITS;
366 }
367
adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts,INT blockNum)368 int adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts, INT blockNum) {
369 int length;
370
371 if (pAdts->bs.num_raw_blocks == 0) {
372 length =
373 (pAdts->bs.frame_length - 7)
374 << 3; /* aac_frame_length subtracted by the header size (7 bytes). */
375 if (pAdts->bs.protection_absent == 0)
376 length -= 16; /* substract 16 bit CRC */
377 } else {
378 if (pAdts->bs.protection_absent) {
379 length = -1; /* raw data block length is unknown */
380 } else {
381 if (blockNum < 0 || blockNum > 3) {
382 length = -1;
383 } else {
384 length = (pAdts->rawDataBlockDist[blockNum] << 3) - 16;
385 }
386 }
387 }
388 if (blockNum == 0 && length > 0) {
389 length -= pAdts->bs.num_pce_bits;
390 }
391 return length;
392 }
393