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1 
2 /* -----------------------------------------------------------------------------------------------------------
3 Software License for The Fraunhofer FDK AAC Codec Library for Android
4 
5 � Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V.
6   All rights reserved.
7 
8  1.    INTRODUCTION
9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
12 
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16 of the MPEG specifications.
17 
18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
24 
25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27 applications information and documentation.
28 
29 2.    COPYRIGHT LICENSE
30 
31 Redistribution and use in source and binary forms, with or without modification, are permitted without
32 payment of copyright license fees provided that you satisfy the following conditions:
33 
34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35 your modifications thereto in source code form.
36 
37 You must retain the complete text of this software license in the documentation and/or other materials
38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40 modifications thereto to recipients of copies in binary form.
41 
42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43 prior written permission.
44 
45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46 software or your modifications thereto.
47 
48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49 and the date of any change. For modified versions of the FDK AAC Codec, the term
50 "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
51 "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
52 
53 3.    NO PATENT LICENSE
54 
55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57 respect to this software.
58 
59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60 by appropriate patent licenses.
61 
62 4.    DISCLAIMER
63 
64 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
65 "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69 or business interruption, however caused and on any theory of liability, whether in contract, strict
70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
71 advised of the possibility of such damage.
72 
73 5.    CONTACT INFORMATION
74 
75 Fraunhofer Institute for Integrated Circuits IIS
76 Attention: Audio and Multimedia Departments - FDK AAC LL
77 Am Wolfsmantel 33
78 91058 Erlangen, Germany
79 
80 www.iis.fraunhofer.de/amm
81 amm-info@iis.fraunhofer.de
82 ----------------------------------------------------------------------------------------------------------- */
83 
84 /******************************** MPEG Audio Encoder **************************
85 
86    Initial author:       M. Lohwasser
87    contents/description: noisedet.c
88                          Routines for Noise Detection
89 
90 ******************************************************************************/
91 
92 #include "noisedet.h"
93 
94 #include "aacenc_pns.h"
95 #include "pnsparam.h"
96 
97 
98 /*****************************************************************************
99 
100     functionname: FDKaacEnc_fuzzyIsSmaller
101     description:  Fuzzy value calculation for "testVal is smaller than refVal"
102     returns:      fuzzy value
103     input:        test and ref Value,
104                   low and high Lim
105     output:       return fuzzy value
106 
107 *****************************************************************************/
FDKaacEnc_fuzzyIsSmaller(FIXP_DBL testVal,FIXP_DBL refVal,FIXP_DBL loLim,FIXP_DBL hiLim)108 static FIXP_SGL FDKaacEnc_fuzzyIsSmaller( FIXP_DBL testVal,
109                                 FIXP_DBL refVal,
110                                 FIXP_DBL loLim,
111                                 FIXP_DBL hiLim )
112 {
113   if (refVal <= FL2FXCONST_DBL(0.0))
114         return( FL2FXCONST_SGL(0.0f) );
115   else if (testVal >= fMult((hiLim>>1)+(loLim>>1), refVal))
116         return( FL2FXCONST_SGL(0.0f) );
117   else  return( (FIXP_SGL)MAXVAL_SGL );
118 }
119 
120 
121 
122 /*****************************************************************************
123 
124     functionname: FDKaacEnc_noiseDetect
125     description:  detect tonal sfb's; two tests
126                   Powerdistribution:
127                     sfb splittet in four regions,
128                     compare the energy in all sections
129                   PsychTonality:
130                     compare tonality from chaosmeasure with reftonality
131     returns:
132     input:        spectrum of one large mdct
133                   number of sfb's
134                   pointer to offset of sfb's
135                   pointer to noiseFuzzyMeasure (modified)
136                   noiseparams struct
137                   pointer to sfb energies
138                   pointer to tonality calculated in chaosmeasure
139     output:       noiseFuzzy Measure
140 
141 *****************************************************************************/
142 
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)143 void FDKaacEnc_noiseDetect(FIXP_DBL    *RESTRICT mdctSpectrum,
144                  INT         *RESTRICT sfbMaxScaleSpec,
145                  INT          sfbActive,
146                  const INT   *RESTRICT sfbOffset,
147                  FIXP_SGL    *RESTRICT noiseFuzzyMeasure,
148                  NOISEPARAMS *np,
149                  FIXP_SGL    *RESTRICT sfbtonality )
150 
151 {
152   int    i, k, sfb, sfbWidth;
153   FIXP_SGL fuzzy, fuzzyTotal;
154   FIXP_DBL refVal, testVal;
155 
156   /***** Start detection phase *****/
157   /* Start noise detection for each band based on a number of checks */
158   for (sfb=0; sfb<sfbActive; sfb++) {
159 
160     fuzzyTotal = (FIXP_SGL)MAXVAL_SGL;
161     sfbWidth = sfbOffset[sfb+1] - sfbOffset[sfb];
162 
163     /* Reset output for lower bands or too small bands */
164     if (sfb < np->startSfb  ||  sfbWidth < np->minSfbWidth) {
165       noiseFuzzyMeasure[sfb] = FL2FXCONST_SGL(0.0f);
166       continue;
167     }
168 
169     if ( (np->detectionAlgorithmFlags & USE_POWER_DISTRIBUTION) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) {
170       FIXP_DBL fhelp1, fhelp2, fhelp3, fhelp4, maxVal, minVal;
171       INT leadingBits = fixMax(0,(sfbMaxScaleSpec[sfb] - 3));         /* max sfbWidth = 96/4 ; 2^5=32 => 5/2 = 3 (spc*spc) */
172 
173       /*  check power distribution in four regions */
174       fhelp1 = fhelp2 = fhelp3 = fhelp4 = FL2FXCONST_DBL(0.0f);
175       k = sfbWidth >>2;  /* Width of a quarter band */
176 
177       for (i=sfbOffset[sfb]; i<sfbOffset[sfb]+k; i++) {
178         fhelp1 = fPow2AddDiv2(fhelp1, mdctSpectrum[i]<<leadingBits);
179         fhelp2 = fPow2AddDiv2(fhelp2, mdctSpectrum[i+k]<<leadingBits);
180         fhelp3 = fPow2AddDiv2(fhelp3, mdctSpectrum[i+2*k]<<leadingBits);
181         fhelp4 = fPow2AddDiv2(fhelp4, mdctSpectrum[i+3*k]<<leadingBits);
182       }
183 
184       /* get max into fhelp: */
185       maxVal = fixMax(fhelp1, fhelp2);
186       maxVal = fixMax(maxVal, fhelp3);
187       maxVal = fixMax(maxVal, fhelp4);
188 
189       /* get min into fhelp1: */
190       minVal = fixMin(fhelp1, fhelp2);
191       minVal = fixMin(minVal, fhelp3);
192       minVal = fixMin(minVal, fhelp4);
193 
194       /* Normalize min and max Val */
195       leadingBits = CountLeadingBits(maxVal);
196       testVal = maxVal << leadingBits;
197       refVal  = minVal << leadingBits;
198 
199       /* calculate fuzzy value for power distribution */
200       testVal = fMultDiv2(testVal, np->powDistPSDcurve[sfb]);
201 
202       fuzzy = FDKaacEnc_fuzzyIsSmaller(testVal,           /* 1/2 * maxValue * PSDcurve */
203                              refVal,            /* 1   * minValue            */
204                              FL2FXCONST_DBL(0.495),  /* 1/2 * loLim  (0.99f/2)    */
205                              FL2FXCONST_DBL(0.505)); /* 1/2 * hiLim  (1.01f/2)    */
206 
207       fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
208     }
209 
210     if ( (np->detectionAlgorithmFlags & USE_PSYCH_TONALITY) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) {
211       /* Detection with tonality-value of psych. acoustic (here: 1 is tonal!)*/
212 
213       testVal = FX_SGL2FX_DBL(sfbtonality[sfb])>>1;          /* 1/2 * sfbTonality         */
214       refVal  = np->refTonality;
215 
216       fuzzy   = FDKaacEnc_fuzzyIsSmaller(testVal,
217                                refVal,
218                                FL2FXCONST_DBL(0.45f),    /* 1/2 * loLim  (0.9f/2)     */
219                                FL2FXCONST_DBL(0.55f));   /* 1/2 * hiLim  (1.1f/2)     */
220 
221       fuzzyTotal = fixMin(fuzzyTotal, fuzzy);
222     }
223 
224 
225     /* Output of final result */
226     noiseFuzzyMeasure[sfb] = fuzzyTotal;
227   }
228 }
229