mirror of https://github.com/mstorsjo/fdk-aac.git
230 lines
8.4 KiB
C
230 lines
8.4 KiB
C
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/* -----------------------------------------------------------------------------------------------------------
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Software License for The Fraunhofer FDK AAC Codec Library for Android
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© Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
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All rights reserved.
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1. INTRODUCTION
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The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
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the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
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This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
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AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
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audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
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independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
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of the MPEG specifications.
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Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
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may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
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individually for the purpose of encoding or decoding bit streams in products that are compliant with
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the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
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these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
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software may already be covered under those patent licenses when it is used for those licensed purposes only.
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Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
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are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
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applications information and documentation.
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2. COPYRIGHT LICENSE
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Redistribution and use in source and binary forms, with or without modification, are permitted without
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payment of copyright license fees provided that you satisfy the following conditions:
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You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
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your modifications thereto in source code form.
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You must retain the complete text of this software license in the documentation and/or other materials
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provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
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You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
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modifications thereto to recipients of copies in binary form.
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The name of Fraunhofer may not be used to endorse or promote products derived from this library without
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prior written permission.
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You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
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software or your modifications thereto.
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Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
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and the date of any change. For modified versions of the FDK AAC Codec, the term
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"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
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"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
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3. NO PATENT LICENSE
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NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
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ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
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respect to this software.
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You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
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by appropriate patent licenses.
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4. DISCLAIMER
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
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"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
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of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
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including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
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or business interruption, however caused and on any theory of liability, whether in contract, strict
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liability, or tort (including negligence), arising in any way out of the use of this software, even if
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advised of the possibility of such damage.
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5. CONTACT INFORMATION
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Fraunhofer Institute for Integrated Circuits IIS
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Attention: Audio and Multimedia Departments - FDK AAC LL
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Am Wolfsmantel 33
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91058 Erlangen, Germany
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www.iis.fraunhofer.de/amm
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amm-info@iis.fraunhofer.de
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----------------------------------------------------------------------------------------------------------- */
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/*************************** Fraunhofer IIS FDK Tools **********************
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Author(s): Haricharan Lakshman, Manuel Jander
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Description: Trigonometric functions fixed point fractional implementation.
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******************************************************************************/
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#include "common_fix.h"
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#include "FDK_tools_rom.h"
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/* Fixed point precision definitions */
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#define Q(format) ((FIXP_DBL)(((LONG)1) << (format)))
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#ifndef M_PI
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#define M_PI (3.14159265358979323846f)
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#endif
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/*!
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* Inverse tangent function.
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*/
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// --- fixp_atan() ----
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#define Q_ATANINP (25) // Input in q25, Output in q30
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#define Q_ATANOUT (30)
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#define ATI_SF ((DFRACT_BITS-1)-Q_ATANINP) // 6
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#define ATI_SCALE ((float)(1<<ATI_SF)) //
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#define ATO_SF ((DFRACT_BITS-1)-Q_ATANOUT) // 1 ] -pi/2 .. pi/2 [
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#define ATO_SCALE ((float)(1<<ATO_SF)) //
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// --- fixp_atan2() ---
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#define Q_ATAN2OUT (29)
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#define AT2O_SF ((DFRACT_BITS-1)-Q_ATAN2OUT) // 2 ] -pi .. pi ]
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#define AT2O_SCALE ((float)(1<<AT2O_SF)) //
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// --------------------
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FIXP_DBL fixp_atan(FIXP_DBL x);
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FIXP_DBL fixp_atan2(FIXP_DBL y, FIXP_DBL x);
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FIXP_DBL fixp_cos(FIXP_DBL x, int scale);
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FIXP_DBL fixp_sin(FIXP_DBL x, int scale);
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#define FIXP_COS_SIN
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#include "FDK_tools_rom.h"
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#define SINETAB SineTable512
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#define LD 9
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#ifndef FUNCTION_inline_fixp_cos_sin
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#define FUNCTION_inline_fixp_cos_sin
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/*
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* Calculates coarse lookup index and sign for sine.
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* Returns delta x residual.
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*/
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static inline FIXP_DBL fixp_sin_cos_residual_inline(FIXP_DBL x, int scale, FIXP_DBL *sine, FIXP_DBL *cosine)
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{
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FIXP_DBL residual;
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int s;
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int shift = (31-scale-LD-1);
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int ssign = 1;
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int csign = 1;
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residual = fMult(x, FL2FXCONST_DBL(1.0/M_PI));
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s = ((LONG)residual) >> shift;
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residual &= ( (1<<shift) - 1 );
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residual = fMult(residual, FL2FXCONST_DBL(M_PI/4.0)) << 2;
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residual <<= scale;
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/* Sine sign symmetry */
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if (s & ((1<<LD)<<1) ) {
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ssign = -ssign;
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}
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/* Cosine sign symmetry */
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if ( (s + (1<<LD)) & ((1<<LD)<<1) ) {
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csign = -csign;
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}
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s = fAbs(s);
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s &= (((1<<LD)<<1)-1); /* Modulo PI */
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if (s > (1<<LD)) {
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s = ((1<<LD)<<1) - s;
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}
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{
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LONG sl, cl;
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/* Because of packed table */
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if (s > (1<<(LD-1))) {
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FIXP_STP tmp;
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/* Cosine/Sine simetry for angles greater than PI/4 */
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s = (1<<LD)-s;
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tmp = SINETAB[s];
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sl = (LONG)tmp.v.re;
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cl = (LONG)tmp.v.im;
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} else {
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FIXP_STP tmp;
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tmp = SINETAB[s];
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sl = (LONG)tmp.v.im;
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cl = (LONG)tmp.v.re;
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}
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#ifdef SINETABLE_16BIT
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*sine = (FIXP_DBL)((sl * ssign) << (DFRACT_BITS-FRACT_BITS));
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*cosine = (FIXP_DBL)((cl * csign) << (DFRACT_BITS-FRACT_BITS));
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#else
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*sine = (FIXP_DBL)(sl * ssign);
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*cosine = (FIXP_DBL)(cl * csign);
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#endif
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}
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return residual;
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}
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/**
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* \brief Calculate cosine and sine value each of 2 angles different angle values.
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* \param x1 first angle value
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* \param x2 second angle value
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* \param scale exponent of x1 and x2
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* \param out pointer to 4 FIXP_DBL locations, were the values cos(x1), sin(x1), cos(x2), sin(x2)
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* will be stored into.
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*/
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static inline void inline_fixp_cos_sin (FIXP_DBL x1, FIXP_DBL x2, const int scale, FIXP_DBL *out)
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{
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FIXP_DBL residual, error0, error1, sine, cosine;
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residual = fixp_sin_cos_residual_inline(x1, scale, &sine, &cosine);
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error0 = fMultDiv2(sine, residual);
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error1 = fMultDiv2(cosine, residual);
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*out++ = cosine - (error0<<1);
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*out++ = sine + (error1<<1);
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residual = fixp_sin_cos_residual_inline(x2, scale, &sine, &cosine);
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error0 = fMultDiv2(sine, residual);
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error1 = fMultDiv2(cosine, residual);
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*out++ = cosine - (error0<<1);
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*out++ = sine + (error1<<1);
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}
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#endif
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