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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 /**************************** SBR encoder library ******************************
96 
97    Author(s):
98 
99    Description:
100 
101 *******************************************************************************/
102 
103 /*!
104   \file
105   \brief  Remaining SBR Bit Writing Routines
106 */
107 
108 #include "env_bit.h"
109 #include "cmondata.h"
110 
111 #ifndef min
112 #define min(a, b) (a < b ? a : b)
113 #endif
114 
115 #ifndef max
116 #define max(a, b) (a > b ? a : b)
117 #endif
118 
119 /* ***************************** crcAdvance **********************************/
120 /**
121  * @fn
122  * @brief    updates crc data register
123  * @return   none
124  *
125  * This function updates the crc register
126  *
127  */
crcAdvance(USHORT crcPoly,USHORT crcMask,USHORT * crc,ULONG bValue,INT bBits)128 static void crcAdvance(USHORT crcPoly, USHORT crcMask, USHORT *crc,
129                        ULONG bValue, INT bBits) {
130   INT i;
131   USHORT flag;
132 
133   for (i = bBits - 1; i >= 0; i--) {
134     flag = ((*crc) & crcMask) ? (1) : (0);
135     flag ^= (bValue & (1 << i)) ? (1) : (0);
136 
137     (*crc) <<= 1;
138     if (flag) (*crc) ^= crcPoly;
139   }
140 }
141 
142 /* ***************************** FDKsbrEnc_InitSbrBitstream
143  * **********************************/
144 /**
145  * @fn
146  * @brief    Inittialisation of sbr bitstream, write of dummy header and CRC
147  * @return   none
148  *
149  *
150  *
151  */
152 
FDKsbrEnc_InitSbrBitstream(HANDLE_COMMON_DATA hCmonData,UCHAR * memoryBase,INT memorySize,HANDLE_FDK_CRCINFO hCrcInfo,UINT sbrSyntaxFlags)153 INT FDKsbrEnc_InitSbrBitstream(
154     HANDLE_COMMON_DATA hCmonData,
155     UCHAR *memoryBase, /*!< Pointer to bitstream buffer */
156     INT memorySize,    /*!< Length of bitstream buffer in bytes */
157     HANDLE_FDK_CRCINFO hCrcInfo, UINT sbrSyntaxFlags) /*!< SBR syntax flags */
158 {
159   INT crcRegion = 0;
160 
161   /* reset bit buffer */
162   FDKresetBitbuffer(&hCmonData->sbrBitbuf, BS_WRITER);
163 
164   FDKinitBitStream(&hCmonData->tmpWriteBitbuf, memoryBase, memorySize, 0,
165                    BS_WRITER);
166 
167   if (sbrSyntaxFlags & SBR_SYNTAX_CRC) {
168     if (sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC) { /* Init and start CRC region */
169       FDKwriteBits(&hCmonData->sbrBitbuf, 0x0, SI_SBR_DRM_CRC_BITS);
170       FDKcrcInit(hCrcInfo, 0x001d, 0xFFFF, SI_SBR_DRM_CRC_BITS);
171       crcRegion = FDKcrcStartReg(hCrcInfo, &hCmonData->sbrBitbuf, 0);
172     } else {
173       FDKwriteBits(&hCmonData->sbrBitbuf, 0x0, SI_SBR_CRC_BITS);
174     }
175   }
176 
177   return (crcRegion);
178 }
179 
180 /* ************************** FDKsbrEnc_AssembleSbrBitstream
181  * *******************************/
182 /**
183  * @fn
184  * @brief    Formats the SBR payload
185  * @return   nothing
186  *
187  * Also the CRC will be calculated here.
188  *
189  */
190 
FDKsbrEnc_AssembleSbrBitstream(HANDLE_COMMON_DATA hCmonData,HANDLE_FDK_CRCINFO hCrcInfo,INT crcRegion,UINT sbrSyntaxFlags)191 void FDKsbrEnc_AssembleSbrBitstream(HANDLE_COMMON_DATA hCmonData,
192                                     HANDLE_FDK_CRCINFO hCrcInfo, INT crcRegion,
193                                     UINT sbrSyntaxFlags) {
194   USHORT crcReg = SBR_CRCINIT;
195   INT numCrcBits, i;
196 
197   /* check if SBR is present */
198   if (hCmonData == NULL) return;
199 
200   hCmonData->sbrFillBits = 0; /* Fill bits are written only for GA streams */
201 
202   if (sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC) {
203     /*
204      * Calculate and write DRM CRC
205      */
206     FDKcrcEndReg(hCrcInfo, &hCmonData->sbrBitbuf, crcRegion);
207     FDKwriteBits(&hCmonData->tmpWriteBitbuf, FDKcrcGetCRC(hCrcInfo) ^ 0xFF,
208                  SI_SBR_DRM_CRC_BITS);
209   } else {
210     if (!(sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY)) {
211       /* Do alignment here, because its defined as part of the
212        * sbr_extension_data */
213       int sbrLoad = hCmonData->sbrHdrBits + hCmonData->sbrDataBits;
214 
215       if (sbrSyntaxFlags & SBR_SYNTAX_CRC) {
216         sbrLoad += SI_SBR_CRC_BITS;
217       }
218 
219       sbrLoad += 4; /* Do byte Align with 4 bit offset. ISO/IEC 14496-3:2005(E)
220                        page 39. */
221 
222       hCmonData->sbrFillBits = (8 - (sbrLoad % 8)) % 8;
223 
224       /*
225         append fill bits
226       */
227       FDKwriteBits(&hCmonData->sbrBitbuf, 0, hCmonData->sbrFillBits);
228 
229       FDK_ASSERT(FDKgetValidBits(&hCmonData->sbrBitbuf) % 8 == 4);
230     }
231 
232     /*
233       calculate crc
234     */
235     if (sbrSyntaxFlags & SBR_SYNTAX_CRC) {
236       FDK_BITSTREAM tmpCRCBuf = hCmonData->sbrBitbuf;
237       FDKresetBitbuffer(&tmpCRCBuf, BS_READER);
238 
239       numCrcBits = hCmonData->sbrHdrBits + hCmonData->sbrDataBits +
240                    hCmonData->sbrFillBits;
241 
242       for (i = 0; i < numCrcBits; i++) {
243         INT bit;
244         bit = FDKreadBits(&tmpCRCBuf, 1);
245         crcAdvance(SBR_CRC_POLY, SBR_CRC_MASK, &crcReg, bit, 1);
246       }
247       crcReg &= (SBR_CRC_RANGE);
248 
249       /*
250        * Write CRC data.
251        */
252       FDKwriteBits(&hCmonData->tmpWriteBitbuf, crcReg, SI_SBR_CRC_BITS);
253     }
254   }
255 
256   FDKsyncCache(&hCmonData->tmpWriteBitbuf);
257 }
258