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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): M. Gayer
+ Description: Fixed point specific mathematical functions
+
+******************************************************************************/
+
+#include "fixpoint_math.h"
+
+
+#define MAX_LD_PRECISION 10
+#define LD_PRECISION 10
+
+/* Taylor series coeffcients for ln(1-x), centered at 0 (MacLaurin polinomial). */
+#ifndef LDCOEFF_16BIT
+LNK_SECTION_CONSTDATA_L1
+static const FIXP_DBL ldCoeff[MAX_LD_PRECISION] = {
+ FL2FXCONST_DBL(-1.0),
+ FL2FXCONST_DBL(-1.0/2.0),
+ FL2FXCONST_DBL(-1.0/3.0),
+ FL2FXCONST_DBL(-1.0/4.0),
+ FL2FXCONST_DBL(-1.0/5.0),
+ FL2FXCONST_DBL(-1.0/6.0),
+ FL2FXCONST_DBL(-1.0/7.0),
+ FL2FXCONST_DBL(-1.0/8.0),
+ FL2FXCONST_DBL(-1.0/9.0),
+ FL2FXCONST_DBL(-1.0/10.0)
+};
+#else
+LNK_SECTION_CONSTDATA_L1
+static const FIXP_SGL ldCoeff[MAX_LD_PRECISION] = {
+ FL2FXCONST_SGL(-1.0),
+ FL2FXCONST_SGL(-1.0/2.0),
+ FL2FXCONST_SGL(-1.0/3.0),
+ FL2FXCONST_SGL(-1.0/4.0),
+ FL2FXCONST_SGL(-1.0/5.0),
+ FL2FXCONST_SGL(-1.0/6.0),
+ FL2FXCONST_SGL(-1.0/7.0),
+ FL2FXCONST_SGL(-1.0/8.0),
+ FL2FXCONST_SGL(-1.0/9.0),
+ FL2FXCONST_SGL(-1.0/10.0)
+};
+#endif
+
+/*****************************************************************************
+
+ functionname: CalcLdData
+ description: Delivers the Logarithm Dualis ld(op)/LD_DATA_SCALING with polynomial approximation.
+ input: Input op is assumed to be double precision fractional 0 < op < 1.0
+ This function does not accept negative values.
+ output: For op == 0, the result is saturated to -1.0
+ This function does not return positive values since input values are treated as fractional values.
+ It does not make sense to input an integer value into this function (and expect a positive output value)
+ since input values are treated as fractional values.
+
+*****************************************************************************/
+
+LNK_SECTION_CODE_L1
+FIXP_DBL CalcLdData(FIXP_DBL op)
+{
+ return fLog2(op, 0);
+}
+
+
+/*****************************************************************************
+ functionname: LdDataVector
+*****************************************************************************/
+LNK_SECTION_CODE_L1
+void LdDataVector( FIXP_DBL *srcVector,
+ FIXP_DBL *destVector,
+ INT n)
+{
+ INT i;
+ for ( i=0; i<n; i++) {
+ destVector[i] = CalcLdData(srcVector[i]);
+ }
+}
+
+
+
+#define MAX_POW2_PRECISION 8
+#ifndef SINETABLE_16BIT
+ #define POW2_PRECISION MAX_POW2_PRECISION
+#else
+ #define POW2_PRECISION 5
+#endif
+
+/*
+ Taylor series coefficients of the function x^2. The first coefficient is
+ ommited (equal to 1.0).
+
+ pow2Coeff[i-1] = (1/i!) d^i(2^x)/dx^i, i=1..MAX_POW2_PRECISION
+ To evaluate the taylor series around x = 0, the coefficients are: 1/!i * ln(2)^i
+ */
+#ifndef POW2COEFF_16BIT
+LNK_SECTION_CONSTDATA_L1
+static const FIXP_DBL pow2Coeff[MAX_POW2_PRECISION] = {
+ FL2FXCONST_DBL(0.693147180559945309417232121458177), /* ln(2)^1 /1! */
+ FL2FXCONST_DBL(0.240226506959100712333551263163332), /* ln(2)^2 /2! */
+ FL2FXCONST_DBL(0.0555041086648215799531422637686218), /* ln(2)^3 /3! */
+ FL2FXCONST_DBL(0.00961812910762847716197907157365887), /* ln(2)^4 /4! */
+ FL2FXCONST_DBL(0.00133335581464284434234122219879962), /* ln(2)^5 /5! */
+ FL2FXCONST_DBL(1.54035303933816099544370973327423e-4), /* ln(2)^6 /6! */
+ FL2FXCONST_DBL(1.52527338040598402800254390120096e-5), /* ln(2)^7 /7! */
+ FL2FXCONST_DBL(1.32154867901443094884037582282884e-6) /* ln(2)^8 /8! */
+};
+#else
+LNK_SECTION_CONSTDATA_L1
+static const FIXP_SGL pow2Coeff[MAX_POW2_PRECISION] = {
+ FL2FXCONST_SGL(0.693147180559945309417232121458177), /* ln(2)^1 /1! */
+ FL2FXCONST_SGL(0.240226506959100712333551263163332), /* ln(2)^2 /2! */
+ FL2FXCONST_SGL(0.0555041086648215799531422637686218), /* ln(2)^3 /3! */
+ FL2FXCONST_SGL(0.00961812910762847716197907157365887), /* ln(2)^4 /4! */
+ FL2FXCONST_SGL(0.00133335581464284434234122219879962), /* ln(2)^5 /5! */
+ FL2FXCONST_SGL(1.54035303933816099544370973327423e-4), /* ln(2)^6 /6! */
+ FL2FXCONST_SGL(1.52527338040598402800254390120096e-5), /* ln(2)^7 /7! */
+ FL2FXCONST_SGL(1.32154867901443094884037582282884e-6) /* ln(2)^8 /8! */
+};
+#endif
+
+
+
+/*****************************************************************************
+
+ functionname: mul_dbl_sgl_rnd
+ description: Multiply with round.
+*****************************************************************************/
+
+/* for rounding a dfract to fract */
+#define ACCU_R (LONG) 0x00008000
+
+LNK_SECTION_CODE_L1
+FIXP_DBL mul_dbl_sgl_rnd (const FIXP_DBL op1, const FIXP_SGL op2)
+{
+ FIXP_DBL prod;
+ LONG v = (LONG)(op1);
+ SHORT u = (SHORT)(op2);
+
+ LONG low = u*(v&SGL_MASK);
+ low = (low+(ACCU_R>>1)) >> (FRACT_BITS-1); /* round */
+ LONG high = u * ((v>>FRACT_BITS)<<1);
+
+ prod = (LONG)(high+low);
+
+ return((FIXP_DBL)prod);
+}
+
+
+/*****************************************************************************
+
+ functionname: CalcInvLdData
+ description: Delivers the inverse of function CalcLdData().
+ Delivers 2^(op*LD_DATA_SCALING)
+ input: Input op is assumed to be fractional -1.0 < op < 1.0
+ output: For op == 0, the result is MAXVAL_DBL (almost 1.0).
+ For negative input values the output should be treated as a positive fractional value.
+ For positive input values the output should be treated as a positive integer value.
+ This function does not output negative values.
+
+*****************************************************************************/
+LNK_SECTION_CODE_L1
+FIXP_DBL CalcInvLdData(FIXP_DBL op)
+{
+ FIXP_DBL result_m;
+
+ if ( op == FL2FXCONST_DBL(0.0f) ) {
+ result_m = (FIXP_DBL)MAXVAL_DBL;
+ }
+ else if ( op < FL2FXCONST_DBL(0.0f) ) {
+ result_m = f2Pow(op, LD_DATA_SHIFT);
+ }
+ else {
+ int result_e;
+
+ result_m = f2Pow(op, LD_DATA_SHIFT, &result_e);
+ result_e = fixMin(fixMax(result_e+1-(DFRACT_BITS-1), -(DFRACT_BITS-1)), (DFRACT_BITS-1)); /* rounding and saturation */
+
+ if ( (result_e>0) && ( result_m > (((FIXP_DBL)MAXVAL_DBL)>>result_e) ) ) {
+ result_m = (FIXP_DBL)MAXVAL_DBL; /* saturate to max representable value */
+ }
+ else {
+ result_m = (scaleValue(result_m, result_e)+(FIXP_DBL)1)>>1; /* descale result + rounding */
+ }
+ }
+ return result_m;
+}
+
+
+
+
+
+/*****************************************************************************
+ functionname: InitLdInt and CalcLdInt
+ description: Create and access table with integer LdData (0 to 193)
+*****************************************************************************/
+
+
+ LNK_SECTION_CONSTDATA_L1
+ static const FIXP_DBL ldIntCoeff[] = {
+ 0x80000001, 0x00000000, 0x02000000, 0x032b8034, 0x04000000, 0x04a4d3c2, 0x052b8034, 0x059d5da0,
+ 0x06000000, 0x06570069, 0x06a4d3c2, 0x06eb3a9f, 0x072b8034, 0x0766a009, 0x079d5da0, 0x07d053f7,
+ 0x08000000, 0x082cc7ee, 0x08570069, 0x087ef05b, 0x08a4d3c2, 0x08c8ddd4, 0x08eb3a9f, 0x090c1050,
+ 0x092b8034, 0x0949a785, 0x0966a009, 0x0982809d, 0x099d5da0, 0x09b74949, 0x09d053f7, 0x09e88c6b,
+ 0x0a000000, 0x0a16bad3, 0x0a2cc7ee, 0x0a423162, 0x0a570069, 0x0a6b3d79, 0x0a7ef05b, 0x0a92203d,
+ 0x0aa4d3c2, 0x0ab7110e, 0x0ac8ddd4, 0x0ada3f60, 0x0aeb3a9f, 0x0afbd42b, 0x0b0c1050, 0x0b1bf312,
+ 0x0b2b8034, 0x0b3abb40, 0x0b49a785, 0x0b584822, 0x0b66a009, 0x0b74b1fd, 0x0b82809d, 0x0b900e61,
+ 0x0b9d5da0, 0x0baa708f, 0x0bb74949, 0x0bc3e9ca, 0x0bd053f7, 0x0bdc899b, 0x0be88c6b, 0x0bf45e09,
+ 0x0c000000, 0x0c0b73cb, 0x0c16bad3, 0x0c21d671, 0x0c2cc7ee, 0x0c379085, 0x0c423162, 0x0c4caba8,
+ 0x0c570069, 0x0c6130af, 0x0c6b3d79, 0x0c7527b9, 0x0c7ef05b, 0x0c88983f, 0x0c92203d, 0x0c9b8926,
+ 0x0ca4d3c2, 0x0cae00d2, 0x0cb7110e, 0x0cc0052b, 0x0cc8ddd4, 0x0cd19bb0, 0x0cda3f60, 0x0ce2c97d,
+ 0x0ceb3a9f, 0x0cf39355, 0x0cfbd42b, 0x0d03fda9, 0x0d0c1050, 0x0d140ca0, 0x0d1bf312, 0x0d23c41d,
+ 0x0d2b8034, 0x0d3327c7, 0x0d3abb40, 0x0d423b08, 0x0d49a785, 0x0d510118, 0x0d584822, 0x0d5f7cff,
+ 0x0d66a009, 0x0d6db197, 0x0d74b1fd, 0x0d7ba190, 0x0d82809d, 0x0d894f75, 0x0d900e61, 0x0d96bdad,
+ 0x0d9d5da0, 0x0da3ee7f, 0x0daa708f, 0x0db0e412, 0x0db74949, 0x0dbda072, 0x0dc3e9ca, 0x0dca258e,
+ 0x0dd053f7, 0x0dd6753e, 0x0ddc899b, 0x0de29143, 0x0de88c6b, 0x0dee7b47, 0x0df45e09, 0x0dfa34e1,
+ 0x0e000000, 0x0e05bf94, 0x0e0b73cb, 0x0e111cd2, 0x0e16bad3, 0x0e1c4dfb, 0x0e21d671, 0x0e275460,
+ 0x0e2cc7ee, 0x0e323143, 0x0e379085, 0x0e3ce5d8, 0x0e423162, 0x0e477346, 0x0e4caba8, 0x0e51daa8,
+ 0x0e570069, 0x0e5c1d0b, 0x0e6130af, 0x0e663b74, 0x0e6b3d79, 0x0e7036db, 0x0e7527b9, 0x0e7a1030,
+ 0x0e7ef05b, 0x0e83c857, 0x0e88983f, 0x0e8d602e, 0x0e92203d, 0x0e96d888, 0x0e9b8926, 0x0ea03232,
+ 0x0ea4d3c2, 0x0ea96df0, 0x0eae00d2, 0x0eb28c7f, 0x0eb7110e, 0x0ebb8e96, 0x0ec0052b, 0x0ec474e4,
+ 0x0ec8ddd4, 0x0ecd4012, 0x0ed19bb0, 0x0ed5f0c4, 0x0eda3f60, 0x0ede8797, 0x0ee2c97d, 0x0ee70525,
+ 0x0eeb3a9f, 0x0eef69ff, 0x0ef39355, 0x0ef7b6b4, 0x0efbd42b, 0x0effebcd, 0x0f03fda9, 0x0f0809cf,
+ 0x0f0c1050, 0x0f10113b, 0x0f140ca0, 0x0f18028d, 0x0f1bf312, 0x0f1fde3d, 0x0f23c41d, 0x0f27a4c0,
+ 0x0f2b8034
+ };
+
+
+ LNK_SECTION_INITCODE
+ void InitLdInt()
+ {
+ /* nothing to do! Use preinitialized logarithm table */
+ }
+
+
+
+LNK_SECTION_CODE_L1
+FIXP_DBL CalcLdInt(INT i)
+{
+ /* calculates ld(op)/LD_DATA_SCALING */
+ /* op is assumed to be an integer value between 1 and 193 */
+
+ FDK_ASSERT((193>0) && ((FIXP_DBL)ldIntCoeff[0]==(FIXP_DBL)0x80000001)); /* tab has to be initialized */
+
+ if ((i>0)&&(i<193))
+ return ldIntCoeff[i];
+ else
+ {
+ return (0);
+ }
+}
+
+
+/*****************************************************************************
+
+ functionname: invSqrtNorm2
+ description: delivers 1/sqrt(op) normalized to .5...1 and the shift value of the OUTPUT
+
+*****************************************************************************/
+#define SQRT_BITS 7
+#define SQRT_VALUES 128
+#define SQRT_BITS_MASK 0x7f
+
+LNK_SECTION_CONSTDATA_L1
+static const FIXP_DBL invSqrtTab[SQRT_VALUES] = {
+ 0x5a827999, 0x5a287e03, 0x59cf8cbb, 0x5977a0ab, 0x5920b4de, 0x58cac480, 0x5875cade, 0x5821c364,
+ 0x57cea99c, 0x577c792f, 0x572b2ddf, 0x56dac38d, 0x568b3631, 0x563c81df, 0x55eea2c3, 0x55a19521,
+ 0x55555555, 0x5509dfd0, 0x54bf311a, 0x547545d0, 0x542c1aa3, 0x53e3ac5a, 0x539bf7cc, 0x5354f9e6,
+ 0x530eafa4, 0x52c91617, 0x52842a5e, 0x523fe9ab, 0x51fc513f, 0x51b95e6b, 0x51770e8e, 0x51355f19,
+ 0x50f44d88, 0x50b3d768, 0x5073fa4f, 0x5034b3e6, 0x4ff601df, 0x4fb7e1f9, 0x4f7a5201, 0x4f3d4fce,
+ 0x4f00d943, 0x4ec4ec4e, 0x4e8986e9, 0x4e4ea718, 0x4e144ae8, 0x4dda7072, 0x4da115d9, 0x4d683948,
+ 0x4d2fd8f4, 0x4cf7f31b, 0x4cc08604, 0x4c898fff, 0x4c530f64, 0x4c1d0293, 0x4be767f5, 0x4bb23df9,
+ 0x4b7d8317, 0x4b4935ce, 0x4b1554a6, 0x4ae1de2a, 0x4aaed0f0, 0x4a7c2b92, 0x4a49ecb3, 0x4a1812fa,
+ 0x49e69d16, 0x49b589bb, 0x4984d7a4, 0x49548591, 0x49249249, 0x48f4fc96, 0x48c5c34a, 0x4896e53c,
+ 0x48686147, 0x483a364c, 0x480c6331, 0x47dee6e0, 0x47b1c049, 0x4784ee5f, 0x4758701c, 0x472c447c,
+ 0x47006a80, 0x46d4e130, 0x46a9a793, 0x467ebcb9, 0x46541fb3, 0x4629cf98, 0x45ffcb80, 0x45d61289,
+ 0x45aca3d5, 0x45837e88, 0x455aa1ca, 0x45320cc8, 0x4509beb0, 0x44e1b6b4, 0x44b9f40b, 0x449275ec,
+ 0x446b3b95, 0x44444444, 0x441d8f3b, 0x43f71bbe, 0x43d0e917, 0x43aaf68e, 0x43854373, 0x435fcf14,
+ 0x433a98c5, 0x43159fdb, 0x42f0e3ae, 0x42cc6397, 0x42a81ef5, 0x42841527, 0x4260458d, 0x423caf8c,
+ 0x4219528b, 0x41f62df1, 0x41d3412a, 0x41b08ba1, 0x418e0cc7, 0x416bc40d, 0x4149b0e4, 0x4127d2c3,
+ 0x41062920, 0x40e4b374, 0x40c3713a, 0x40a261ef, 0x40818511, 0x4060da21, 0x404060a1, 0x40201814
+};
+
+LNK_SECTION_INITCODE
+void InitInvSqrtTab()
+{
+ /* nothing to do !
+ use preinitialized square root table
+ */
+}
+
+
+
+#if !defined(FUNCTION_invSqrtNorm2)
+/*****************************************************************************
+ delivers 1/sqrt(op) normalized to .5...1 and the shift value of the OUTPUT,
+ i.e. the denormalized result is 1/sqrt(op) = invSqrtNorm(op) * 2^(shift)
+ uses Newton-iteration for approximation
+ Q(n+1) = Q(n) + Q(n) * (0.5 - 2 * V * Q(n)^2)
+ with Q = 0.5* V ^-0.5; 0.5 <= V < 1.0
+*****************************************************************************/
+FIXP_DBL invSqrtNorm2(FIXP_DBL op, INT *shift)
+{
+
+ FIXP_DBL val = op ;
+ FIXP_DBL reg1, reg2, regtmp ;
+
+ if (val == FL2FXCONST_DBL(0.0)) {
+ *shift = 1 ;
+ return((LONG)1); /* minimum positive value */
+ }
+
+
+ /* normalize input, calculate shift value */
+ FDK_ASSERT(val > FL2FXCONST_DBL(0.0));
+ *shift = fNormz(val) - 1; /* CountLeadingBits() is not necessary here since test value is always > 0 */
+ val <<=*shift ; /* normalized input V */
+ *shift+=2 ; /* bias for exponent */
+
+ /* Newton iteration of 1/sqrt(V) */
+ reg1 = invSqrtTab[ (INT)(val>>(DFRACT_BITS-1-(SQRT_BITS+1))) & SQRT_BITS_MASK ];
+ reg2 = FL2FXCONST_DBL(0.0625f); /* 0.5 >> 3 */
+
+ regtmp= fPow2Div2(reg1); /* a = Q^2 */
+ regtmp= reg2 - fMultDiv2(regtmp, val); /* b = 0.5 - 2 * V * Q^2 */
+ reg1 += (fMultDiv2(regtmp, reg1)<<4); /* Q = Q + Q*b */
+
+ /* calculate the output exponent = input exp/2 */
+ if (*shift & 0x00000001) { /* odd shift values ? */
+ reg2 = FL2FXCONST_DBL(0.707106781186547524400844362104849f); /* 1/sqrt(2); */
+ reg1 = fMultDiv2(reg1, reg2) << 2;
+ }
+
+ *shift = *shift>>1;
+
+ return(reg1);
+}
+#endif /* !defined(FUNCTION_invSqrtNorm2) */
+
+/*****************************************************************************
+
+ functionname: sqrtFixp
+ description: delivers sqrt(op)
+
+*****************************************************************************/
+FIXP_DBL sqrtFixp(FIXP_DBL op)
+{
+ INT tmp_exp = 0;
+ FIXP_DBL tmp_inv = invSqrtNorm2(op, &tmp_exp);
+
+ FDK_ASSERT(tmp_exp > 0) ;
+ return( (FIXP_DBL) ( fMultDiv2( (op<<(tmp_exp-1)), tmp_inv ) << 2 ));
+}
+
+
+#if !defined(FUNCTION_schur_div)
+/*****************************************************************************
+
+ functionname: schur_div
+ description: delivers op1/op2 with op3-bit accuracy
+
+*****************************************************************************/
+
+
+FIXP_DBL schur_div(FIXP_DBL num, FIXP_DBL denum, INT count)
+{
+ INT L_num = (LONG)num>>1;
+ INT L_denum = (LONG)denum>>1;
+ INT div = 0;
+ INT k = count;
+
+ FDK_ASSERT (num>=(FIXP_DBL)0);
+ FDK_ASSERT (denum>(FIXP_DBL)0);
+ FDK_ASSERT (num <= denum);
+
+ if (L_num != 0)
+ while (--k)
+ {
+ div <<= 1;
+ L_num <<= 1;
+ if (L_num >= L_denum)
+ {
+ L_num -= L_denum;
+ div++;
+ }
+ }
+ return (FIXP_DBL)(div << (DFRACT_BITS - count));
+}
+
+
+#endif /* !defined(FUNCTION_schur_div) */
+
+
+#ifndef FUNCTION_fMultNorm
+FIXP_DBL fMultNorm(FIXP_DBL f1, FIXP_DBL f2, INT *result_e)
+{
+ INT product = 0;
+ INT norm_f1, norm_f2;
+
+ if ( (f1 == (FIXP_DBL)0) || (f2 == (FIXP_DBL)0) ) {
+ *result_e = 0;
+ return (FIXP_DBL)0;
+ }
+ norm_f1 = CountLeadingBits(f1);
+ f1 = f1 << norm_f1;
+ norm_f2 = CountLeadingBits(f2);
+ f2 = f2 << norm_f2;
+
+ product = fMult(f1, f2);
+ *result_e = - (norm_f1 + norm_f2);
+
+ return (FIXP_DBL)product;
+}
+#endif
+
+#ifndef FUNCTION_fDivNorm
+FIXP_DBL fDivNorm(FIXP_DBL L_num, FIXP_DBL L_denum, INT *result_e)
+{
+ FIXP_DBL div;
+ INT norm_num, norm_den;
+
+ FDK_ASSERT (L_num >= (FIXP_DBL)0);
+ FDK_ASSERT (L_denum > (FIXP_DBL)0);
+
+ if(L_num == (FIXP_DBL)0)
+ {
+ *result_e = 0;
+ return ((FIXP_DBL)0);
+ }
+
+ norm_num = CountLeadingBits(L_num);
+ L_num = L_num << norm_num;
+ L_num = L_num >> 1;
+ *result_e = - norm_num + 1;
+
+ norm_den = CountLeadingBits(L_denum);
+ L_denum = L_denum << norm_den;
+ *result_e -= - norm_den;
+
+ div = schur_div(L_num, L_denum, FRACT_BITS);
+
+ return div;
+}
+#endif /* !FUNCTION_fDivNorm */
+
+#ifndef FUNCTION_fDivNorm
+FIXP_DBL fDivNorm(FIXP_DBL num, FIXP_DBL denom)
+{
+ INT e;
+ FIXP_DBL res;
+
+ FDK_ASSERT (denom >= num);
+
+ res = fDivNorm(num, denom, &e);
+
+ /* Avoid overflow since we must output a value with exponent 0
+ there is no other choice than saturating to almost 1.0f */
+ if(res == (FIXP_DBL)(1<<(DFRACT_BITS-2)) && e == 1)
+ {
+ res = (FIXP_DBL)MAXVAL_DBL;
+ }
+ else
+ {
+ res = scaleValue(res, e);
+ }
+
+ return res;
+}
+#endif /* !FUNCTION_fDivNorm */
+
+#ifndef FUNCTION_fDivNormHighPrec
+FIXP_DBL fDivNormHighPrec(FIXP_DBL num, FIXP_DBL denom, INT *result_e)
+{
+ FIXP_DBL div;
+ INT norm_num, norm_den;
+
+ FDK_ASSERT (num >= (FIXP_DBL)0);
+ FDK_ASSERT (denom > (FIXP_DBL)0);
+
+ if(num == (FIXP_DBL)0)
+ {
+ *result_e = 0;
+ return ((FIXP_DBL)0);
+ }
+
+ norm_num = CountLeadingBits(num);
+ num = num << norm_num;
+ num = num >> 1;
+ *result_e = - norm_num + 1;
+
+ norm_den = CountLeadingBits(denom);
+ denom = denom << norm_den;
+ *result_e -= - norm_den;
+
+ div = schur_div(num, denom, 31);
+ return div;
+}
+#endif /* !FUNCTION_fDivNormHighPrec */
+
+
+
+FIXP_DBL CalcLog2(FIXP_DBL base_m, INT base_e, INT *result_e)
+{
+ return fLog2(base_m, base_e, result_e);
+}
+
+FIXP_DBL f2Pow(
+ const FIXP_DBL exp_m, const INT exp_e,
+ INT *result_e
+ )
+{
+ FIXP_DBL frac_part, result_m;
+ INT int_part;
+
+ if (exp_e > 0)
+ {
+ INT exp_bits = DFRACT_BITS-1 - exp_e;
+ int_part = exp_m >> exp_bits;
+ frac_part = exp_m - (FIXP_DBL)(int_part << exp_bits);
+ frac_part = frac_part << exp_e;
+ }
+ else
+ {
+ int_part = 0;
+ frac_part = exp_m >> -exp_e;
+ }
+
+ /* Best accuracy is around 0, so try to get there with the fractional part. */
+ if( frac_part > FL2FXCONST_DBL(0.5f) )
+ {
+ int_part = int_part + 1;
+ frac_part = frac_part + FL2FXCONST_DBL(-1.0f);
+ }
+ if( frac_part < FL2FXCONST_DBL(-0.5f) )
+ {
+ int_part = int_part - 1;
+ frac_part = -(FL2FXCONST_DBL(-1.0f) - frac_part);
+ }
+
+ /* Evaluate taylor polynomial which approximates 2^x */
+ {
+ FIXP_DBL p;
+
+ /* result_m ~= 2^frac_part */
+ p = frac_part;
+ /* First taylor series coefficient a_0 = 1.0, scaled by 0.5 due to fMultDiv2(). */
+ result_m = FL2FXCONST_DBL(1.0f/2.0f);
+ for (INT i = 0; i < POW2_PRECISION; i++) {
+ /* next taylor series term: a_i * x^i, x=0 */
+ result_m = fMultAddDiv2(result_m, pow2Coeff[i], p);
+ p = fMult(p, frac_part);
+ }
+ }
+
+ /* "+ 1" compensates fMultAddDiv2() of the polynomial evaluation above. */
+ *result_e = int_part + 1;
+
+ return result_m;
+}
+
+FIXP_DBL f2Pow(
+ const FIXP_DBL exp_m, const INT exp_e
+ )
+{
+ FIXP_DBL result_m;
+ INT result_e;
+
+ result_m = f2Pow(exp_m, exp_e, &result_e);
+ result_e = fixMin(DFRACT_BITS-1,fixMax(-(DFRACT_BITS-1),result_e));
+
+ return scaleValue(result_m, result_e);
+}
+
+FIXP_DBL fPow(
+ FIXP_DBL base_m, INT base_e,
+ FIXP_DBL exp_m, INT exp_e,
+ INT *result_e
+ )
+{
+ INT ans_lg2_e, baselg2_e;
+ FIXP_DBL base_lg2, ans_lg2, result;
+
+ /* Calc log2 of base */
+ base_lg2 = fLog2(base_m, base_e, &baselg2_e);
+
+ /* Prepare exp */
+ {
+ INT leadingBits;
+
+ leadingBits = CountLeadingBits(fAbs(exp_m));
+ exp_m = exp_m << leadingBits;
+ exp_e -= leadingBits;
+ }
+
+ /* Calc base pow exp */
+ ans_lg2 = fMult(base_lg2, exp_m);
+ ans_lg2_e = exp_e + baselg2_e;
+
+ /* Calc antilog */
+ result = f2Pow(ans_lg2, ans_lg2_e, result_e);
+
+ return result;
+}
+
+FIXP_DBL fLdPow(
+ FIXP_DBL baseLd_m,
+ INT baseLd_e,
+ FIXP_DBL exp_m, INT exp_e,
+ INT *result_e
+ )
+{
+ INT ans_lg2_e;
+ FIXP_DBL ans_lg2, result;
+
+ /* Prepare exp */
+ {
+ INT leadingBits;
+
+ leadingBits = CountLeadingBits(fAbs(exp_m));
+ exp_m = exp_m << leadingBits;
+ exp_e -= leadingBits;
+ }
+
+ /* Calc base pow exp */
+ ans_lg2 = fMult(baseLd_m, exp_m);
+ ans_lg2_e = exp_e + baseLd_e;
+
+ /* Calc antilog */
+ result = f2Pow(ans_lg2, ans_lg2_e, result_e);
+
+ return result;
+}
+
+FIXP_DBL fLdPow(
+ FIXP_DBL baseLd_m, INT baseLd_e,
+ FIXP_DBL exp_m, INT exp_e
+ )
+{
+ FIXP_DBL result_m;
+ int result_e;
+
+ result_m = fLdPow(baseLd_m, baseLd_e, exp_m, exp_e, &result_e);
+
+ return SATURATE_SHIFT(result_m, -result_e, DFRACT_BITS);
+}
+
+FIXP_DBL fPowInt(
+ FIXP_DBL base_m, INT base_e,
+ INT exp,
+ INT *pResult_e
+ )
+{
+ FIXP_DBL result;
+
+ if (exp != 0) {
+ INT result_e = 0;
+
+ if (base_m != (FIXP_DBL)0) {
+ {
+ INT leadingBits;
+ leadingBits = CountLeadingBits( base_m );
+ base_m <<= leadingBits;
+ base_e -= leadingBits;
+ }
+
+ result = base_m;
+
+ {
+ int i;
+ for (i = 1; i < fAbs(exp); i++) {
+ result = fMult(result, base_m);
+ }
+ }
+
+ if (exp < 0) {
+ /* 1.0 / ans */
+ result = fDivNorm( FL2FXCONST_DBL(0.5f), result, &result_e );
+ result_e++;
+ } else {
+ int ansScale = CountLeadingBits( result );
+ result <<= ansScale;
+ result_e -= ansScale;
+ }
+
+ result_e += exp * base_e;
+
+ } else {
+ result = (FIXP_DBL)0;
+ }
+ *pResult_e = result_e;
+ }
+ else {
+ result = FL2FXCONST_DBL(0.5f);
+ *pResult_e = 1;
+ }
+
+ return result;
+}
+
+FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e, INT *result_e)
+{
+ FIXP_DBL result_m;
+
+ /* Short cut for zero and negative numbers. */
+ if ( x_m <= FL2FXCONST_DBL(0.0f) ) {
+ *result_e = DFRACT_BITS-1;
+ return FL2FXCONST_DBL(-1.0f);
+ }
+
+ /* Calculate log2() */
+ {
+ FIXP_DBL px2_m, x2_m;
+
+ /* Move input value x_m * 2^x_e toward 1.0, where the taylor approximation
+ of the function log(1-x) centered at 0 is most accurate. */
+ {
+ INT b_norm;
+
+ b_norm = fNormz(x_m)-1;
+ x2_m = x_m << b_norm;
+ x_e = x_e - b_norm;
+ }
+
+ /* map x from log(x) domain to log(1-x) domain. */
+ x2_m = - (x2_m + FL2FXCONST_DBL(-1.0) );
+
+ /* Taylor polinomial approximation of ln(1-x) */
+ result_m = FL2FXCONST_DBL(0.0);
+ px2_m = x2_m;
+ for (int i=0; i<LD_PRECISION; i++) {
+ result_m = fMultAddDiv2(result_m, ldCoeff[i], px2_m);
+ px2_m = fMult(px2_m, x2_m);
+ }
+ /* Multiply result with 1/ln(2) = 1.0 + 0.442695040888 (get log2(x) from ln(x) result). */
+ result_m = fMultAddDiv2(result_m, result_m, FL2FXCONST_DBL(2.0*0.4426950408889634073599246810019));
+
+ /* Add exponent part. log2(x_m * 2^x_e) = log2(x_m) + x_e */
+ if (x_e != 0)
+ {
+ int enorm;
+
+ enorm = DFRACT_BITS - fNorm((FIXP_DBL)x_e);
+ /* The -1 in the right shift of result_m compensates the fMultDiv2() above in the taylor polinomial evaluation loop.*/
+ result_m = (result_m >> (enorm-1)) + ((FIXP_DBL)x_e << (DFRACT_BITS-1-enorm));
+
+ *result_e = enorm;
+ } else {
+ /* 1 compensates the fMultDiv2() above in the taylor polinomial evaluation loop.*/
+ *result_e = 1;
+ }
+ }
+
+ return result_m;
+}
+
+FIXP_DBL fLog2(FIXP_DBL x_m, INT x_e)
+{
+ if ( x_m <= FL2FXCONST_DBL(0.0f) ) {
+ x_m = FL2FXCONST_DBL(-1.0f);
+ }
+ else {
+ INT result_e;
+ x_m = fLog2(x_m, x_e, &result_e);
+ x_m = scaleValue(x_m, result_e-LD_DATA_SHIFT);
+ }
+ return x_m;
+}
+
+
+
+