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 encoder library *********************
96 
97    Author(s):   Alex Groeschel
98 
99    Description: ADTS Transport Headers support
100 
101 *******************************************************************************/
102 
103 #include "tpenc_adts.h"
104 
105 #include "tpenc_lib.h"
106 #include "tpenc_asc.h"
107 
adtsWrite_CrcStartReg(HANDLE_ADTS pAdts,HANDLE_FDK_BITSTREAM hBs,int mBits)108 int adtsWrite_CrcStartReg(
109     HANDLE_ADTS pAdts,        /*!< pointer to adts stucture */
110     HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
111     int mBits                 /*!< number of bits in crc region */
112 ) {
113   if (pAdts->protection_absent) {
114     return 0;
115   }
116   return (FDKcrcStartReg(&pAdts->crcInfo, hBs, mBits));
117 }
118 
adtsWrite_CrcEndReg(HANDLE_ADTS pAdts,HANDLE_FDK_BITSTREAM hBs,int reg)119 void adtsWrite_CrcEndReg(
120     HANDLE_ADTS pAdts,        /*!< pointer to adts crc info stucture */
121     HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
122     int reg                   /*!< crc region */
123 ) {
124   if (pAdts->protection_absent == 0) {
125     FDKcrcEndReg(&pAdts->crcInfo, hBs, reg);
126   }
127 }
128 
adtsWrite_GetHeaderBits(HANDLE_ADTS hAdts)129 int adtsWrite_GetHeaderBits(HANDLE_ADTS hAdts) {
130   int bits = 0;
131 
132   if (hAdts->currentBlock == 0) {
133     /* Static and variable header bits */
134     bits = 56;
135     if (!hAdts->protection_absent) {
136       /* Add header/ single raw data block CRC bits */
137       bits += 16;
138       if (hAdts->num_raw_blocks > 0) {
139         /* Add bits of raw data block position markers */
140         bits += (hAdts->num_raw_blocks) * 16;
141       }
142     }
143   }
144   if (!hAdts->protection_absent && hAdts->num_raw_blocks > 0) {
145     /* Add raw data block CRC bits. Not really part of the header, put they
146      * cause bit overhead to be accounted. */
147     bits += 16;
148   }
149 
150   hAdts->headerBits = bits;
151 
152   return bits;
153 }
154 
adtsWrite_Init(HANDLE_ADTS hAdts,CODER_CONFIG * config)155 INT adtsWrite_Init(HANDLE_ADTS hAdts, CODER_CONFIG *config) {
156   /* Sanity checks */
157   if (config->nSubFrames < 1 || config->nSubFrames > 4 ||
158       (int)config->aot > 4 || (int)config->aot < 1) {
159     return -1;
160   }
161 
162   /* fixed header */
163   if (config->flags & CC_MPEG_ID) {
164     hAdts->mpeg_id = 0; /* MPEG 4 */
165   } else {
166     hAdts->mpeg_id = 1; /* MPEG 2 */
167   }
168   hAdts->layer = 0;
169   hAdts->protection_absent = !(config->flags & CC_PROTECTION);
170   hAdts->profile = ((int)config->aot) - 1;
171   hAdts->sample_freq_index = getSamplingRateIndex(config->samplingRate, 4);
172   hAdts->sample_freq = config->samplingRate;
173   hAdts->private_bit = 0;
174   hAdts->channel_mode = config->channelMode;
175   hAdts->original = 0;
176   hAdts->home = 0;
177   /* variable header */
178   hAdts->copyright_id = 0;
179   hAdts->copyright_start = 0;
180 
181   hAdts->num_raw_blocks = config->nSubFrames - 1; /* 0 means 1 raw data block */
182 
183   hAdts->channel_config_zero = config->channelConfigZero;
184 
185   FDKcrcInit(&hAdts->crcInfo, 0x8005, 0xFFFF, 16);
186 
187   hAdts->currentBlock = 0;
188 
189   return 0;
190 }
191 
adtsWrite_EncodeHeader(HANDLE_ADTS hAdts,HANDLE_FDK_BITSTREAM hBitStream,int buffer_fullness,int frame_length)192 int adtsWrite_EncodeHeader(HANDLE_ADTS hAdts, HANDLE_FDK_BITSTREAM hBitStream,
193                            int buffer_fullness, int frame_length) {
194   INT crcIndex = 0;
195 
196   hAdts->headerBits = adtsWrite_GetHeaderBits(hAdts);
197 
198   FDK_ASSERT(((frame_length + hAdts->headerBits) / 8) < 0x2000); /*13 bit*/
199   FDK_ASSERT(buffer_fullness < 0x800);                           /* 11 bit   */
200 
201   if (!hAdts->protection_absent) {
202     FDKcrcReset(&hAdts->crcInfo);
203   }
204 
205   if (hAdts->currentBlock == 0) {
206     FDKresetBitbuffer(hBitStream, BS_WRITER);
207   }
208 
209   hAdts->subFrameStartBit = FDKgetValidBits(hBitStream);
210 
211   /* Skip new header if this is raw data block 1..n */
212   if (hAdts->currentBlock == 0) {
213     FDKresetBitbuffer(hBitStream, BS_WRITER);
214 
215     if (hAdts->num_raw_blocks == 0) {
216       crcIndex = adtsWrite_CrcStartReg(hAdts, hBitStream, 0);
217     }
218 
219     /* fixed header */
220     FDKwriteBits(hBitStream, 0xFFF, 12);
221     FDKwriteBits(hBitStream, hAdts->mpeg_id, 1);
222     FDKwriteBits(hBitStream, hAdts->layer, 2);
223     FDKwriteBits(hBitStream, hAdts->protection_absent, 1);
224     FDKwriteBits(hBitStream, hAdts->profile, 2);
225     FDKwriteBits(hBitStream, hAdts->sample_freq_index, 4);
226     FDKwriteBits(hBitStream, hAdts->private_bit, 1);
227     FDKwriteBits(
228         hBitStream,
229         getChannelConfig(hAdts->channel_mode, hAdts->channel_config_zero), 3);
230     FDKwriteBits(hBitStream, hAdts->original, 1);
231     FDKwriteBits(hBitStream, hAdts->home, 1);
232     /* variable header */
233     FDKwriteBits(hBitStream, hAdts->copyright_id, 1);
234     FDKwriteBits(hBitStream, hAdts->copyright_start, 1);
235     FDKwriteBits(hBitStream, (frame_length + hAdts->headerBits) >> 3, 13);
236     FDKwriteBits(hBitStream, buffer_fullness, 11);
237     FDKwriteBits(hBitStream, hAdts->num_raw_blocks, 2);
238 
239     if (!hAdts->protection_absent) {
240       int i;
241 
242       /* End header CRC portion for single raw data block and write dummy zero
243        * values for unknown fields. */
244       if (hAdts->num_raw_blocks == 0) {
245         adtsWrite_CrcEndReg(hAdts, hBitStream, crcIndex);
246       } else {
247         for (i = 0; i < hAdts->num_raw_blocks; i++) {
248           FDKwriteBits(hBitStream, 0, 16);
249         }
250       }
251       FDKwriteBits(hBitStream, 0, 16);
252     }
253   } /* End of ADTS header */
254 
255   return 0;
256 }
257 
adtsWrite_EndRawDataBlock(HANDLE_ADTS hAdts,HANDLE_FDK_BITSTREAM hBs,int * pBits)258 void adtsWrite_EndRawDataBlock(HANDLE_ADTS hAdts, HANDLE_FDK_BITSTREAM hBs,
259                                int *pBits) {
260   if (!hAdts->protection_absent) {
261     FDK_BITSTREAM bsWriter;
262 
263     FDKinitBitStream(&bsWriter, hBs->hBitBuf.Buffer, hBs->hBitBuf.bufSize, 0,
264                      BS_WRITER);
265     FDKpushFor(&bsWriter, 56);
266 
267     if (hAdts->num_raw_blocks == 0) {
268       FDKwriteBits(&bsWriter, FDKcrcGetCRC(&hAdts->crcInfo), 16);
269     } else {
270       int distance;
271 
272       /* Write CRC of current raw data block */
273       FDKwriteBits(hBs, FDKcrcGetCRC(&hAdts->crcInfo), 16);
274 
275       /* Write distance to current data block */
276       if (hAdts->currentBlock < hAdts->num_raw_blocks) {
277         FDKpushFor(&bsWriter, hAdts->currentBlock * 16);
278         distance =
279             FDKgetValidBits(hBs) - (56 + (hAdts->num_raw_blocks) * 16 + 16);
280         FDKwriteBits(&bsWriter, distance >> 3, 16);
281       }
282     }
283     FDKsyncCache(&bsWriter);
284   }
285 
286   /* Write total frame lenth for multiple raw data blocks and header CRC */
287   if (hAdts->num_raw_blocks > 0 &&
288       hAdts->currentBlock == hAdts->num_raw_blocks) {
289     FDK_BITSTREAM bsWriter;
290     int crcIndex = 0;
291 
292     FDKinitBitStream(&bsWriter, hBs->hBitBuf.Buffer, hBs->hBitBuf.bufSize, 0,
293                      BS_WRITER);
294 
295     if (!hAdts->protection_absent) {
296       FDKcrcReset(&hAdts->crcInfo);
297       crcIndex = FDKcrcStartReg(&hAdts->crcInfo, &bsWriter, 0);
298     }
299     /* Write total frame length */
300     FDKpushFor(&bsWriter, 56 - 28 + 2);
301     FDKwriteBits(&bsWriter, FDKgetValidBits(hBs) >> 3, 13);
302 
303     /* Write header CRC */
304     if (!hAdts->protection_absent) {
305       FDKpushFor(&bsWriter, 11 + 2 + (hAdts->num_raw_blocks) * 16);
306       FDKcrcEndReg(&hAdts->crcInfo, &bsWriter, crcIndex);
307       FDKwriteBits(&bsWriter, FDKcrcGetCRC(&hAdts->crcInfo), 16);
308     }
309     FDKsyncCache(&bsWriter);
310   }
311 
312   /* Correct *pBits to reflect the amount of bits of the current subframe */
313   *pBits -= hAdts->subFrameStartBit;
314   if (!hAdts->protection_absent && hAdts->num_raw_blocks > 0) {
315     /* Fixup CRC bits, since they come after each raw data block */
316     *pBits += 16;
317   }
318   hAdts->currentBlock++;
319 }
320