| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. |
| All rights reserved. |
| |
| 1. INTRODUCTION |
| The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements |
| the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. |
| This FDK AAC Codec software is intended to be used on a wide variety of Android devices. |
| |
| AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual |
| audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by |
| independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part |
| of the MPEG specifications. |
| |
| Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) |
| may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners |
| individually for the purpose of encoding or decoding bit streams in products that are compliant with |
| the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license |
| these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec |
| software may already be covered under those patent licenses when it is used for those licensed purposes only. |
| |
| Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, |
| are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional |
| applications information and documentation. |
| |
| 2. COPYRIGHT LICENSE |
| |
| Redistribution and use in source and binary forms, with or without modification, are permitted without |
| payment of copyright license fees provided that you satisfy the following conditions: |
| |
| You must retain the complete text of this software license in redistributions of the FDK AAC Codec or |
| your modifications thereto in source code form. |
| |
| You must retain the complete text of this software license in the documentation and/or other materials |
| provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. |
| You must make available free of charge copies of the complete source code of the FDK AAC Codec and your |
| modifications thereto to recipients of copies in binary form. |
| |
| The name of Fraunhofer may not be used to endorse or promote products derived from this library without |
| prior written permission. |
| |
| You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec |
| software or your modifications thereto. |
| |
| Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software |
| and the date of any change. For modified versions of the FDK AAC Codec, the term |
| "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term |
| "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." |
| |
| 3. NO PATENT LICENSE |
| |
| NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, |
| ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with |
| respect to this software. |
| |
| You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized |
| by appropriate patent licenses. |
| |
| 4. DISCLAIMER |
| |
| This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors |
| "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties |
| of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR |
| CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, |
| including but not limited to procurement of substitute goods or services; loss of use, data, or profits, |
| or business interruption, however caused and on any theory of liability, whether in contract, strict |
| liability, or tort (including negligence), arising in any way out of the use of this software, even if |
| advised of the possibility of such damage. |
| |
| 5. CONTACT INFORMATION |
| |
| Fraunhofer Institute for Integrated Circuits IIS |
| Attention: Audio and Multimedia Departments - FDK AAC LL |
| Am Wolfsmantel 33 |
| 91058 Erlangen, Germany |
| |
| www.iis.fraunhofer.de/amm |
| amm-info@iis.fraunhofer.de |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| /******************************** MPEG Audio Encoder ************************** |
| |
| Initial author: M. Lohwasser |
| contents/description: noisedet.c |
| Routines for Noise Detection |
| |
| ******************************************************************************/ |
| |
| #include "noisedet.h" |
| |
| #include "aacenc_pns.h" |
| #include "pnsparam.h" |
| |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_fuzzyIsSmaller |
| description: Fuzzy value calculation for "testVal is smaller than refVal" |
| returns: fuzzy value |
| input: test and ref Value, |
| low and high Lim |
| output: return fuzzy value |
| |
| *****************************************************************************/ |
| static FIXP_SGL FDKaacEnc_fuzzyIsSmaller( FIXP_DBL testVal, |
| FIXP_DBL refVal, |
| FIXP_DBL loLim, |
| FIXP_DBL hiLim ) |
| { |
| if (refVal <= FL2FXCONST_DBL(0.0)) |
| return( FL2FXCONST_SGL(0.0f) ); |
| else if (testVal >= fMult((hiLim>>1)+(loLim>>1), refVal)) |
| return( FL2FXCONST_SGL(0.0f) ); |
| else return( (FIXP_SGL)MAXVAL_SGL ); |
| } |
| |
| |
| |
| /***************************************************************************** |
| |
| functionname: FDKaacEnc_noiseDetect |
| description: detect tonal sfb's; two tests |
| Powerdistribution: |
| sfb splittet in four regions, |
| compare the energy in all sections |
| PsychTonality: |
| compare tonality from chaosmeasure with reftonality |
| returns: |
| input: spectrum of one large mdct |
| number of sfb's |
| pointer to offset of sfb's |
| pointer to noiseFuzzyMeasure (modified) |
| noiseparams struct |
| pointer to sfb energies |
| pointer to tonality calculated in chaosmeasure |
| output: noiseFuzzy Measure |
| |
| *****************************************************************************/ |
| |
| void 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 ) |
| |
| { |
| int i, k, sfb, sfbWidth; |
| FIXP_SGL fuzzy, fuzzyTotal; |
| FIXP_DBL refVal, testVal; |
| |
| /***** Start detection phase *****/ |
| /* Start noise detection for each band based on a number of checks */ |
| for (sfb=0; sfb<sfbActive; sfb++) { |
| |
| fuzzyTotal = (FIXP_SGL)MAXVAL_SGL; |
| sfbWidth = sfbOffset[sfb+1] - sfbOffset[sfb]; |
| |
| /* Reset output for lower bands or too small bands */ |
| if (sfb < np->startSfb || sfbWidth < np->minSfbWidth) { |
| noiseFuzzyMeasure[sfb] = FL2FXCONST_SGL(0.0f); |
| continue; |
| } |
| |
| if ( (np->detectionAlgorithmFlags & USE_POWER_DISTRIBUTION) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) { |
| FIXP_DBL fhelp1, fhelp2, fhelp3, fhelp4, maxVal, minVal; |
| INT leadingBits = fixMax(0,(sfbMaxScaleSpec[sfb] - 3)); /* max sfbWidth = 96/4 ; 2^5=32 => 5/2 = 3 (spc*spc) */ |
| |
| /* check power distribution in four regions */ |
| fhelp1 = fhelp2 = fhelp3 = fhelp4 = FL2FXCONST_DBL(0.0f); |
| k = sfbWidth >>2; /* Width of a quarter band */ |
| |
| for (i=sfbOffset[sfb]; i<sfbOffset[sfb]+k; i++) { |
| fhelp1 = fPow2AddDiv2(fhelp1, mdctSpectrum[i]<<leadingBits); |
| fhelp2 = fPow2AddDiv2(fhelp2, mdctSpectrum[i+k]<<leadingBits); |
| fhelp3 = fPow2AddDiv2(fhelp3, mdctSpectrum[i+2*k]<<leadingBits); |
| fhelp4 = fPow2AddDiv2(fhelp4, mdctSpectrum[i+3*k]<<leadingBits); |
| } |
| |
| /* get max into fhelp: */ |
| maxVal = fixMax(fhelp1, fhelp2); |
| maxVal = fixMax(maxVal, fhelp3); |
| maxVal = fixMax(maxVal, fhelp4); |
| |
| /* get min into fhelp1: */ |
| minVal = fixMin(fhelp1, fhelp2); |
| minVal = fixMin(minVal, fhelp3); |
| minVal = fixMin(minVal, fhelp4); |
| |
| /* Normalize min and max Val */ |
| leadingBits = CountLeadingBits(maxVal); |
| testVal = maxVal << leadingBits; |
| refVal = minVal << leadingBits; |
| |
| /* calculate fuzzy value for power distribution */ |
| testVal = fMultDiv2(testVal, np->powDistPSDcurve[sfb]); |
| |
| fuzzy = FDKaacEnc_fuzzyIsSmaller(testVal, /* 1/2 * maxValue * PSDcurve */ |
| refVal, /* 1 * minValue */ |
| FL2FXCONST_DBL(0.495), /* 1/2 * loLim (0.99f/2) */ |
| FL2FXCONST_DBL(0.505)); /* 1/2 * hiLim (1.01f/2) */ |
| |
| fuzzyTotal = fixMin(fuzzyTotal, fuzzy); |
| } |
| |
| if ( (np->detectionAlgorithmFlags & USE_PSYCH_TONALITY) && (fuzzyTotal > FL2FXCONST_SGL(0.5f)) ) { |
| /* Detection with tonality-value of psych. acoustic (here: 1 is tonal!)*/ |
| |
| testVal = FX_SGL2FX_DBL(sfbtonality[sfb])>>1; /* 1/2 * sfbTonality */ |
| refVal = np->refTonality; |
| |
| fuzzy = FDKaacEnc_fuzzyIsSmaller(testVal, |
| refVal, |
| FL2FXCONST_DBL(0.45f), /* 1/2 * loLim (0.9f/2) */ |
| FL2FXCONST_DBL(0.55f)); /* 1/2 * hiLim (1.1f/2) */ |
| |
| fuzzyTotal = fixMin(fuzzyTotal, fuzzy); |
| } |
| |
| |
| /* Output of final result */ |
| noiseFuzzyMeasure[sfb] = fuzzyTotal; |
| } |
| } |
