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. Lohwasser
98
99 Description: noisedet.c
100 Routines for Noise Detection
101
102 *******************************************************************************/
103
104 #include "noisedet.h"
105
106 #include "aacenc_pns.h"
107 #include "pnsparam.h"
108
109 /*****************************************************************************
110
111 functionname: FDKaacEnc_fuzzyIsSmaller
112 description: Fuzzy value calculation for "testVal is smaller than refVal"
113 returns: fuzzy value
114 input: test and ref Value,
115 low and high Lim
116 output: return fuzzy value
117
118 *****************************************************************************/
FDKaacEnc_fuzzyIsSmaller(FIXP_DBL testVal,FIXP_DBL refVal,FIXP_DBL loLim,FIXP_DBL hiLim)119 static FIXP_SGL FDKaacEnc_fuzzyIsSmaller(FIXP_DBL testVal, FIXP_DBL refVal,
120 FIXP_DBL loLim, FIXP_DBL hiLim) {
121 if (refVal <= FL2FXCONST_DBL(0.0))
122 return (FL2FXCONST_SGL(0.0f));
123 else if (testVal >= fMult((hiLim >> 1) + (loLim >> 1), refVal))
124 return (FL2FXCONST_SGL(0.0f));
125 else
126 return ((FIXP_SGL)MAXVAL_SGL);
127 }
128
129 /*****************************************************************************
130
131 functionname: FDKaacEnc_noiseDetect
132 description: detect tonal sfb's; two tests
133 Powerdistribution:
134 sfb splittet in four regions,
135 compare the energy in all sections
136 PsychTonality:
137 compare tonality from chaosmeasure with reftonality
138 returns:
139 input: spectrum of one large mdct
140 number of sfb's
141 pointer to offset of sfb's
142 pointer to noiseFuzzyMeasure (modified)
143 noiseparams struct
144 pointer to sfb energies
145 pointer to tonality calculated in chaosmeasure
146 output: noiseFuzzy Measure
147
148 *****************************************************************************/
149
FDKaacEnc_noiseDetect(FIXP_DBL * RESTRICT mdctSpectrum,INT * RESTRICT sfbMaxScaleSpec,INT sfbActive,const INT * RESTRICT sfbOffset,FIXP_SGL * RESTRICT noiseFuzzyMeasure,NOISEPARAMS * np,FIXP_SGL * RESTRICT sfbtonality)150 void FDKaacEnc_noiseDetect(FIXP_DBL *RESTRICT mdctSpectrum,
151 INT *RESTRICT sfbMaxScaleSpec, INT sfbActive,
152 const INT *RESTRICT sfbOffset,
153 FIXP_SGL *RESTRICT noiseFuzzyMeasure,
154 NOISEPARAMS *np, FIXP_SGL *RESTRICT sfbtonality)
155
156 {
157 int i, k, sfb, sfbWidth;
158 FIXP_SGL fuzzy, fuzzyTotal;
159 FIXP_DBL refVal, testVal;
160
161 /***** Start detection phase *****/
162 /* Start noise detection for each band based on a number of checks */
163 for (sfb = 0; sfb < sfbActive; sfb++) {
164 fuzzyTotal = (FIXP_SGL)MAXVAL_SGL;
165 sfbWidth = sfbOffset[sfb + 1] - sfbOffset[sfb];
166
167 /* Reset output for lower bands or too small bands */
168 if (sfb < np->startSfb || sfbWidth < np->minSfbWidth) {
169 noiseFuzzyMeasure[sfb] = FL2FXCONST_SGL(0.0f);
170 continue;
171 }
172
173 if ((np->detectionAlgorithmFlags & USE_POWER_DISTRIBUTION) &&
174 (fuzzyTotal > FL2FXCONST_SGL(0.5f))) {
175 FIXP_DBL fhelp1, fhelp2, fhelp3, fhelp4, maxVal, minVal;
176 INT leadingBits = fixMax(
177 0, (sfbMaxScaleSpec[sfb] -
178 3)); /* max sfbWidth = 96/4 ; 2^5=32 => 5/2 = 3 (spc*spc) */
179
180 /* check power distribution in four regions */
181 fhelp1 = fhelp2 = fhelp3 = fhelp4 = FL2FXCONST_DBL(0.0f);
182 k = sfbWidth >> 2; /* Width of a quarter band */
183
184 for (i = sfbOffset[sfb]; i < sfbOffset[sfb] + k; i++) {
185 fhelp1 = fPow2AddDiv2(fhelp1, mdctSpectrum[i] << leadingBits);
186 fhelp2 = fPow2AddDiv2(fhelp2, mdctSpectrum[i + k] << leadingBits);
187 fhelp3 = fPow2AddDiv2(fhelp3, mdctSpectrum[i + 2 * k] << leadingBits);
188 fhelp4 = fPow2AddDiv2(fhelp4, mdctSpectrum[i + 3 * k] << leadingBits);
189 }
190
191 /* get max into fhelp: */
192 maxVal = fixMax(fhelp1, fhelp2);
193 maxVal = fixMax(maxVal, fhelp3);
194 maxVal = fixMax(maxVal, fhelp4);
195
196 /* get min into fhelp1: */
197 minVal = fixMin(fhelp1, fhelp2);
198 minVal = fixMin(minVal, fhelp3);
199 minVal = fixMin(minVal, fhelp4);
200
201 /* Normalize min and max Val */
202 leadingBits = CountLeadingBits(maxVal);
203 testVal = maxVal << leadingBits;
204 refVal = minVal << leadingBits;
205
206 /* calculate fuzzy value for power distribution */
207 testVal = fMultDiv2(testVal, np->powDistPSDcurve[sfb]);
208
209 fuzzy = FDKaacEnc_fuzzyIsSmaller(
210 testVal, /* 1/2 * maxValue * PSDcurve */
211 refVal, /* 1 * minValue */
212 FL2FXCONST_DBL(0.495), /* 1/2 * loLim (0.99f/2) */
213 FL2FXCONST_DBL(0.505)); /* 1/2 * hiLim (1.01f/2) */
214
215 fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
216 }
217
218 if ((np->detectionAlgorithmFlags & USE_PSYCH_TONALITY) &&
219 (fuzzyTotal > FL2FXCONST_SGL(0.5f))) {
220 /* Detection with tonality-value of psych. acoustic (here: 1 is tonal!)*/
221
222 testVal = FX_SGL2FX_DBL(sfbtonality[sfb]) >> 1; /* 1/2 * sfbTonality */
223 refVal = np->refTonality;
224
225 fuzzy = FDKaacEnc_fuzzyIsSmaller(
226 testVal, refVal, FL2FXCONST_DBL(0.45f), /* 1/2 * loLim (0.9f/2) */
227 FL2FXCONST_DBL(0.55f)); /* 1/2 * hiLim (1.1f/2) */
228
229 fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
230 }
231
232 /* Output of final result */
233 noiseFuzzyMeasure[sfb] = fuzzyTotal;
234 }
235 }
236