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+
+/* -----------------------------------------------------------------------------------------------------------
+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
+----------------------------------------------------------------------------------------------------------- */
+
+/*************************** 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;
+}
+
+
+
+
+