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 /**************************** AAC encoder library ******************************
96
97 Author(s): M. Werner
98
99 Description: Chaos measure calculation
100
101 *******************************************************************************/
102
103 #include "chaosmeasure.h"
104
105 /*****************************************************************************
106 functionname: FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast
107 description: Eberlein method of chaos measure calculation by high-pass
108 filtering amplitude spectrum
109 A special case of FDKaacEnc_CalculateChaosMeasureTonalGeneric
110 -- highly optimized
111 *****************************************************************************/
FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast(FIXP_DBL * RESTRICT paMDCTDataNM0,INT numberOfLines,FIXP_DBL * RESTRICT chaosMeasure)112 static void FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast(
113 FIXP_DBL *RESTRICT paMDCTDataNM0, INT numberOfLines,
114 FIXP_DBL *RESTRICT chaosMeasure) {
115 INT i, j;
116
117 /* calculate chaos measure by "peak filter" */
118 /* make even and odd pass through data */
119 FIXP_DBL left_0_div2,
120 center_0; /* left, center tap of filter, even numbered */
121 FIXP_DBL left_1_div2, center_1; /* left, center tap of filter, odd numbered */
122
123 left_0_div2 = (FIXP_DBL)(((LONG)paMDCTDataNM0[0] ^
124 ((LONG)paMDCTDataNM0[0] >> (DFRACT_BITS - 1))) >>
125 1);
126 left_1_div2 = (FIXP_DBL)(((LONG)paMDCTDataNM0[1] ^
127 ((LONG)paMDCTDataNM0[1] >> (DFRACT_BITS - 1))) >>
128 1);
129 center_0 = (FIXP_DBL)((LONG)paMDCTDataNM0[2] ^
130 ((LONG)paMDCTDataNM0[2] >> (DFRACT_BITS - 1)));
131 center_1 = (FIXP_DBL)((LONG)paMDCTDataNM0[3] ^
132 ((LONG)paMDCTDataNM0[3] >> (DFRACT_BITS - 1)));
133
134 for (j = 2; j < numberOfLines - 2; j += 2) {
135 FIXP_DBL right_0 =
136 (FIXP_DBL)((LONG)paMDCTDataNM0[j + 2] ^
137 ((LONG)paMDCTDataNM0[j + 2] >> (DFRACT_BITS - 1)));
138 FIXP_DBL tmp_0 = left_0_div2 + (right_0 >> 1);
139 FIXP_DBL right_1 =
140 (FIXP_DBL)((LONG)paMDCTDataNM0[j + 3] ^
141 ((LONG)paMDCTDataNM0[j + 3] >> (DFRACT_BITS - 1)));
142 FIXP_DBL tmp_1 = left_1_div2 + (right_1 >> 1);
143
144 if (tmp_0 < center_0) {
145 INT leadingBits = CntLeadingZeros(center_0) - 1;
146 tmp_0 = schur_div(tmp_0 << leadingBits, center_0 << leadingBits, 8);
147 tmp_0 = fMult(tmp_0, tmp_0);
148 } else {
149 tmp_0 = (FIXP_DBL)MAXVAL_DBL;
150 }
151 chaosMeasure[j + 0] = tmp_0;
152 left_0_div2 = center_0 >> 1;
153 center_0 = right_0;
154
155 if (tmp_1 < center_1) {
156 INT leadingBits = CntLeadingZeros(center_1) - 1;
157 tmp_1 = schur_div(tmp_1 << leadingBits, center_1 << leadingBits, 8);
158 tmp_1 = fMult(tmp_1, tmp_1);
159 } else {
160 tmp_1 = (FIXP_DBL)MAXVAL_DBL;
161 }
162
163 left_1_div2 = center_1 >> 1;
164 center_1 = right_1;
165 chaosMeasure[j + 1] = tmp_1;
166 }
167
168 /* provide chaos measure for first few lines */
169 chaosMeasure[0] = chaosMeasure[2];
170 chaosMeasure[1] = chaosMeasure[2];
171
172 /* provide chaos measure for last few lines */
173 for (i = (numberOfLines - 3); i < numberOfLines; i++)
174 chaosMeasure[i] = FL2FXCONST_DBL(0.5);
175 }
176
177 /*****************************************************************************
178 functionname: FDKaacEnc_CalculateChaosMeasure
179 description: calculates a chaosmeasure for every line, different methods
180 are available. 0 means tonal, 1 means noiselike
181 returns:
182 input: MDCT data, number of lines
183 output: chaosMeasure
184 *****************************************************************************/
FDKaacEnc_CalculateChaosMeasure(FIXP_DBL * paMDCTDataNM0,INT numberOfLines,FIXP_DBL * chaosMeasure)185 void FDKaacEnc_CalculateChaosMeasure(FIXP_DBL *paMDCTDataNM0, INT numberOfLines,
186 FIXP_DBL *chaosMeasure)
187
188 {
189 FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast(
190 paMDCTDataNM0, numberOfLines, chaosMeasure);
191 }
192