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 surround encoder library *************************
96
97 Author(s): M. Multrus
98
99 Description: Encoder Library
100 Filter functions
101
102 *******************************************************************************/
103
104 /* Includes ******************************************************************/
105 #include "sacenc_filter.h"
106
107 /* Defines *******************************************************************/
108
109 /* Data Types ****************************************************************/
110 typedef struct T_DC_FILTER {
111 FIXP_DBL c__FDK;
112 FIXP_DBL state__FDK;
113
114 } DC_FILTER;
115
116 /* Constants *****************************************************************/
117
118 /* Function / Class Declarations *********************************************/
119
120 /* Function / Class Definition ***********************************************/
fdk_sacenc_createDCFilter(HANDLE_DC_FILTER * hDCFilter)121 FDK_SACENC_ERROR fdk_sacenc_createDCFilter(HANDLE_DC_FILTER *hDCFilter) {
122 FDK_SACENC_ERROR error = SACENC_OK;
123
124 if (NULL == hDCFilter) {
125 error = SACENC_INVALID_HANDLE;
126 } else {
127 FDK_ALLOCATE_MEMORY_1D(*hDCFilter, 1, DC_FILTER);
128 }
129 return error;
130
131 bail:
132 fdk_sacenc_destroyDCFilter(hDCFilter);
133 return ((SACENC_OK == error) ? SACENC_MEMORY_ERROR : error);
134 }
135
fdk_sacenc_initDCFilter(HANDLE_DC_FILTER hDCFilter,const UINT sampleRate)136 FDK_SACENC_ERROR fdk_sacenc_initDCFilter(HANDLE_DC_FILTER hDCFilter,
137 const UINT sampleRate) {
138 FDK_SACENC_ERROR error = SACENC_OK;
139
140 FIXP_DBL expC;
141 int s;
142
143 /* Conversion for use of CalcInvLdData: e^x = 2^(x*log10(e)/log10(2) =
144 CalcInvLdData(x*log10(e)/log10(2)/64.0) 1.44269504089 = log10(e)/log10(2)
145 0.5 = scale constant value with 1 Bits
146 */
147 expC = fDivNormHighPrec((FIXP_DBL)20, (FIXP_DBL)sampleRate, &s);
148 expC = fMultDiv2(FL2FXCONST_DBL(-1.44269504089 * 0.5), expC) >>
149 (LD_DATA_SHIFT - 1 - 1);
150
151 if (s < 0)
152 expC = expC >> (-s);
153 else
154 expC = expC << (s);
155
156 expC = CalcInvLdData(expC);
157
158 hDCFilter->c__FDK = expC;
159 hDCFilter->state__FDK = FL2FXCONST_DBL(0.0f);
160
161 return error;
162 }
163
fdk_sacenc_destroyDCFilter(HANDLE_DC_FILTER * hDCFilter)164 FDK_SACENC_ERROR fdk_sacenc_destroyDCFilter(HANDLE_DC_FILTER *hDCFilter) {
165 FDK_SACENC_ERROR error = SACENC_OK;
166
167 if ((hDCFilter != NULL) && (*hDCFilter != NULL)) {
168 FDKfree(*hDCFilter);
169
170 *hDCFilter = NULL;
171 }
172
173 return error;
174 }
175
fdk_sacenc_applyDCFilter(HANDLE_DC_FILTER hDCFilter,const INT_PCM * const signalIn,INT_PCM * const signalOut,const INT signalLength)176 FDK_SACENC_ERROR fdk_sacenc_applyDCFilter(HANDLE_DC_FILTER hDCFilter,
177 const INT_PCM *const signalIn,
178 INT_PCM *const signalOut,
179 const INT signalLength) {
180 FDK_SACENC_ERROR error = SACENC_OK;
181
182 if ((hDCFilter == NULL) || (signalIn == NULL) || (signalOut == NULL)) {
183 error = SACENC_INVALID_HANDLE;
184 } else {
185 const INT_PCM *const x = signalIn;
186 INT_PCM *const y = signalOut;
187 const FIXP_DBL c = hDCFilter->c__FDK;
188 FIXP_DBL *const state = &hDCFilter->state__FDK;
189 int i;
190 FIXP_DBL x0, x1, y1;
191
192 x1 = x0 = FX_PCM2FX_DBL(x[0]) >> DC_FILTER_SF;
193 y1 = x0 + (*state);
194
195 for (i = 1; i < signalLength; i++) {
196 x0 = FX_PCM2FX_DBL(x[i]) >> DC_FILTER_SF;
197 y[i - 1] = FX_DBL2FX_PCM(y1);
198 y1 = x0 - x1 + fMult(c, y1);
199 x1 = x0;
200 }
201
202 *state = fMult(c, y1) - x1;
203 y[i - 1] = FX_DBL2FX_PCM(y1);
204 }
205
206 return error;
207 }
208