| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2013 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 |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| /*************************** Fraunhofer IIS FDK Tools ********************** |
| |
| Author(s): Haricharan Lakshman, Manuel Jander |
| Description: Trigonometric functions fixed point fractional implementation. |
| |
| ******************************************************************************/ |
| |
| #include "FDK_trigFcts.h" |
| |
| #include "fixpoint_math.h" |
| |
| |
| |
| |
| #define IMPROVE_ATAN2_ACCURACY 1 // 0 --> 59 dB SNR 1 --> 65 dB SNR |
| #define MINSFTAB 7 |
| #define MAXSFTAB 25 |
| |
| #if IMPROVE_ATAN2_ACCURACY |
| static const FIXP_DBL f_atan_expand_range[MAXSFTAB-(MINSFTAB-1)] = |
| { |
| /***************************************************************************** |
| * |
| * Table holds fixp_atan() output values which are outside of input range |
| * of fixp_atan() to improve SNR of fixp_atan2(). |
| * |
| * This Table might also be used in fixp_atan() [todo] so there a wider input |
| * range can be covered, too. |
| * |
| * Matlab (generate table): |
| * for scl = 7:25 % MINSFTAB .. MAXSFTAB |
| * at=atan(0.5 *(2^scl)); % 0.5 because get in 'middle' area of current scale level 'scl' |
| * at/2 % div at by ATO_SCALE |
| * end |
| * |
| * Table divided by 2=ATO_SCALE <-- SF=ATO_SF |
| *****************************************************************************/ |
| FL2FXCONST_DBL(7.775862990872099e-001), FL2FXCONST_DBL(7.814919928673978e-001), FL2FXCONST_DBL(7.834450483314648e-001), |
| FL2FXCONST_DBL(7.844216021392089e-001), FL2FXCONST_DBL(7.849098823026687e-001), FL2FXCONST_DBL(7.851540227918509e-001), |
| FL2FXCONST_DBL(7.852760930873737e-001), FL2FXCONST_DBL(7.853371282415015e-001), FL2FXCONST_DBL(7.853676458193612e-001), |
| FL2FXCONST_DBL(7.853829046083906e-001), FL2FXCONST_DBL(7.853905340029177e-001), FL2FXCONST_DBL(7.853943487001828e-001), |
| FL2FXCONST_DBL(7.853962560488155e-001), FL2FXCONST_DBL(7.853972097231319e-001), FL2FXCONST_DBL(7.853976865602901e-001), |
| FL2FXCONST_DBL(7.853979249788692e-001), FL2FXCONST_DBL(7.853980441881587e-001), FL2FXCONST_DBL(7.853981037928035e-001), |
| FL2FXCONST_DBL(7.853981335951259e-001) |
| // pi/4 = 0.785398163397448 = pi/2/ATO_SCALE |
| }; |
| #endif |
| |
| FIXP_DBL fixp_atan2(FIXP_DBL y, FIXP_DBL x) |
| { |
| FIXP_DBL q; |
| FIXP_DBL at; // atan out |
| FIXP_DBL at2; // atan2 out |
| FIXP_DBL ret = FL2FXCONST_DBL(-1.0f); |
| INT sf,sfo,stf; |
| |
| // --- division |
| |
| if (y > FL2FXCONST_DBL(0.0f)) |
| { |
| if (x > FL2FXCONST_DBL(0.0f)) { |
| q = fDivNormHighPrec( y, x, &sf); // both pos. |
| } |
| else if (x < FL2FXCONST_DBL(0.0f)) { |
| q = -fDivNormHighPrec( y,-x, &sf); // x neg. |
| } |
| else {//(x ==FL2FXCONST_DBL(0.0f)) |
| q = FL2FXCONST_DBL(+1.0f); // y/x = pos/zero = +Inf |
| sf = 0; |
| } |
| } |
| else if (y < FL2FXCONST_DBL(0.0f)) |
| { |
| if (x > FL2FXCONST_DBL(0.0f)) { |
| q = -fDivNormHighPrec(-y, x, &sf); // y neg. |
| } |
| else if (x < FL2FXCONST_DBL(0.0f)) { |
| q = fDivNormHighPrec(-y,-x, &sf); // both neg. |
| } |
| else {//(x ==FL2FXCONST_DBL(0.0f)) |
| q = FL2FXCONST_DBL(-1.0f); // y/x = neg/zero = -Inf |
| sf = 0; |
| } |
| } |
| else { // (y ==FL2FXCONST_DBL(0.0f)) |
| q = FL2FXCONST_DBL(0.0f); |
| sf = 0; |
| } |
| sfo = sf; |
| |
| // --- atan() |
| |
| if ( sfo > ATI_SF ) { |
| // --- could not calc fixp_atan() here bec of input data out of range |
| // ==> therefore give back boundary values |
| |
| #if IMPROVE_ATAN2_ACCURACY |
| if (sfo > MAXSFTAB) sfo = MAXSFTAB; |
| #endif |
| |
| if ( q > FL2FXCONST_DBL(0.0f) ) { |
| #if IMPROVE_ATAN2_ACCURACY |
| at = +f_atan_expand_range[sfo-ATI_SF-1]; |
| #else |
| at = FL2FXCONST_DBL( +M_PI/2 / ATO_SCALE); |
| #endif |
| } |
| else if ( q < FL2FXCONST_DBL(0.0f) ) { |
| #if IMPROVE_ATAN2_ACCURACY |
| at = -f_atan_expand_range[sfo-ATI_SF-1]; |
| #else |
| at = FL2FXCONST_DBL( -M_PI/2 / ATO_SCALE); |
| #endif |
| } |
| else { // q== FL2FXCONST_DBL(0.0f) |
| at = FL2FXCONST_DBL( 0.0f ); |
| } |
| }else{ |
| // --- calc of fixp_atan() is possible; input data within range |
| // ==> set q on fixed scale level as desired from fixp_atan() |
| stf = sfo - ATI_SF; |
| if (stf > 0) q = q << (INT)fMin( stf,DFRACT_BITS-1); |
| else q = q >> (INT)fMin(-stf,DFRACT_BITS-1); |
| at = fixp_atan(q); // ATO_SF |
| } |
| |
| // --- atan2() |
| |
| at2 = at >> (AT2O_SF - ATO_SF); // now AT2O_SF for atan2 |
| if ( x > FL2FXCONST_DBL(0.0f) ) { |
| ret = at2; |
| } |
| else if ( x < FL2FXCONST_DBL(0.0f) ) { |
| if ( y >= FL2FXCONST_DBL(0.0f) ) { |
| ret = at2 + FL2FXCONST_DBL( M_PI / AT2O_SCALE); |
| } else { |
| ret = at2 - FL2FXCONST_DBL( M_PI / AT2O_SCALE); |
| } |
| } |
| else { |
| // x == 0 |
| if ( y > FL2FXCONST_DBL(0.0f) ) { |
| ret = FL2FXCONST_DBL( +M_PI/2 / AT2O_SCALE); |
| } |
| else if ( y < FL2FXCONST_DBL(0.0f) ) { |
| ret = FL2FXCONST_DBL( -M_PI/2 / AT2O_SCALE); |
| } |
| else if ( y == FL2FXCONST_DBL(0.0f) ) { |
| ret = FL2FXCONST_DBL(0.0f); |
| } |
| } |
| return ret; |
| } |
| |
| |
| FIXP_DBL fixp_atan(FIXP_DBL x) |
| { |
| INT sign; |
| FIXP_DBL result, temp; |
| |
| // SNR of fixp_atan() = 56 dB |
| FIXP_DBL ONEBY3P56 = (FIXP_DBL)0x26800000; // 1.0/3.56 in q31 |
| FIXP_DBL P281 = (FIXP_DBL)0x00013000; // 0.281 in q18 |
| FIXP_DBL ONEP571 = (FIXP_DBL)0x6487ef00; // 1.571 in q30 |
| |
| if (x < FIXP_DBL(0)) { |
| sign = 1; |
| x = - x ; |
| } else { |
| sign = 0; |
| } |
| |
| /* calc of arctan */ |
| if(x < ( Q(Q_ATANINP)-FL2FXCONST_DBL(0.00395)) ) |
| { |
| INT res_e; |
| |
| temp = fPow2(x); // q25 * q25 - (DFRACT_BITS-1) = q19 |
| temp = fMult(temp, ONEBY3P56); // q19 * q31 - (DFRACT_BITS-1) = q19 |
| temp = temp + Q(19); // q19 + q19 = q19 |
| result = fDivNorm(x, temp, &res_e); |
| result = scaleValue(result, (Q_ATANOUT-Q_ATANINP+19-DFRACT_BITS+1) + res_e ); |
| } |
| else if( x < FL2FXCONST_DBL(1.28/64.0) ) |
| { |
| FIXP_DBL delta_fix; |
| FIXP_DBL PI_BY_4 = FL2FXCONST_DBL(3.1415926/4.0) >> 1; /* pi/4 in q30 */ |
| |
| delta_fix = (x - FL2FXCONST_DBL(1.0/64.0)) << 5; /* q30 */ |
| result = PI_BY_4 + (delta_fix >> 1) - (fPow2Div2(delta_fix)); |
| } |
| else |
| { |
| INT res_e; |
| |
| temp = fPow2Div2(x); // q25 * q25 - (DFRACT_BITS-1) - 1 = q18 |
| temp = temp + P281; // q18 + q18 = q18 |
| result = fDivNorm(x, temp, &res_e); |
| result = scaleValue(result, (Q_ATANOUT-Q_ATANINP+18-DFRACT_BITS+1) + res_e ); |
| result = ONEP571 - result; // q30 + q30 = q30 |
| } |
| if (sign) { |
| result = -result; |
| } |
| |
| return(result); |
| } |
| |
| |
| |
| #include "FDK_tools_rom.h" |
| |
| FIXP_DBL fixp_cos(FIXP_DBL x, int scale) |
| { |
| FIXP_DBL residual, error, sine, cosine; |
| |
| residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); |
| error = fMult(sine, residual); |
| |
| return cosine - error; |
| } |
| |
| FIXP_DBL fixp_sin(FIXP_DBL x, int scale) |
| { |
| FIXP_DBL residual, error, sine, cosine; |
| |
| residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); |
| error = fMult(cosine, residual); |
| |
| return sine + error; |
| } |
| |
| void fixp_cos_sin (FIXP_DBL x, int scale, FIXP_DBL *cos, FIXP_DBL *sin) |
| { |
| FIXP_DBL residual, error0, error1, sine, cosine; |
| |
| residual = fixp_sin_cos_residual_inline(x, scale, &sine, &cosine); |
| error0 = fMult(sine, residual); |
| error1 = fMult(cosine, residual); |
| *cos = cosine - error0; |
| *sin = sine + error1; |
| } |
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