1 2/* ----------------------------------------------------------------------------------------------------------- 3Software License for The Fraunhofer FDK AAC Codec Library for Android 4 5� Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur F�rderung der angewandten Forschung e.V. 6 All rights reserved. 7 8 1. INTRODUCTION 9The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements 10the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio. 11This FDK AAC Codec software is intended to be used on a wide variety of Android devices. 12 13AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual 14audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by 15independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part 16of the MPEG specifications. 17 18Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer) 19may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners 20individually for the purpose of encoding or decoding bit streams in products that are compliant with 21the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license 22these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec 23software may already be covered under those patent licenses when it is used for those licensed purposes only. 24 25Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality, 26are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional 27applications information and documentation. 28 292. COPYRIGHT LICENSE 30 31Redistribution and use in source and binary forms, with or without modification, are permitted without 32payment of copyright license fees provided that you satisfy the following conditions: 33 34You must retain the complete text of this software license in redistributions of the FDK AAC Codec or 35your modifications thereto in source code form. 36 37You must retain the complete text of this software license in the documentation and/or other materials 38provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form. 39You must make available free of charge copies of the complete source code of the FDK AAC Codec and your 40modifications thereto to recipients of copies in binary form. 41 42The name of Fraunhofer may not be used to endorse or promote products derived from this library without 43prior written permission. 44 45You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec 46software or your modifications thereto. 47 48Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software 49and the date of any change. For modified versions of the FDK AAC Codec, the term 50"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term 51"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android." 52 533. NO PATENT LICENSE 54 55NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer, 56ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with 57respect to this software. 58 59You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized 60by appropriate patent licenses. 61 624. DISCLAIMER 63 64This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors 65"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties 66of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 67CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages, 68including but not limited to procurement of substitute goods or services; loss of use, data, or profits, 69or business interruption, however caused and on any theory of liability, whether in contract, strict 70liability, or tort (including negligence), arising in any way out of the use of this software, even if 71advised of the possibility of such damage. 72 735. CONTACT INFORMATION 74 75Fraunhofer Institute for Integrated Circuits IIS 76Attention: Audio and Multimedia Departments - FDK AAC LL 77Am Wolfsmantel 33 7891058 Erlangen, Germany 79 80www.iis.fraunhofer.de/amm 81amm-info@iis.fraunhofer.de 82----------------------------------------------------------------------------------------------------------- */ 83 84/*************************** Fraunhofer IIS FDK Tools ********************** 85 86 Author(s): Manuel Jander, Josef Hoepfl 87 Description: MDCT routines 88 89******************************************************************************/ 90 91#ifndef __MDCT_H__ 92#define __MDCT_H__ 93 94 95 96#include "common_fix.h" 97 98#define MDCT_OUT_HEADROOM 2 /* Output additional headroom */ 99#define MDCT_OUTPUT_SCALE (DFRACT_BITS-SAMPLE_BITS-MDCT_OUT_HEADROOM) 100/* Refer to "Output word length" in ISO/IEC 14496-3:2008(E) 23.2.3.6 */ 101#define MDCT_OUTPUT_GAIN 16 102 103#if (SAMPLE_BITS == DFRACT_BITS) 104#define IMDCT_SCALE(x) (INT_PCM)SATURATE_LEFT_SHIFT(x, -MDCT_OUTPUT_SCALE, SAMPLE_BITS) 105#else 106#define IMDCT_SCALE(x) (INT_PCM)SATURATE_RIGHT_SHIFT(x, MDCT_OUTPUT_SCALE, SAMPLE_BITS) 107#endif 108#define IMDCT_SCALE_DBL(x) (FIXP_DBL)(x) 109 110/** 111 * \brief MDCT persistent data 112 */ 113typedef struct { 114 union { 115 FIXP_DBL *freq; 116 FIXP_DBL *time; 117 } overlap; /**< Pointer to overlap memory */ 118 119 const FIXP_WTP *prev_wrs; /**< pointer to previous right window slope */ 120 int prev_tl; /**< previous tranform length */ 121 int prev_nr; /**< previous right window offset */ 122 int prev_fr; /**< previous right window slope length */ 123 int ov_offset; /**< overlap time data fill level */ 124 int ov_size; /**< Overlap buffer size in words */ 125 126} mdct_t; 127 128typedef mdct_t* H_MDCT; 129 130/** 131 * \brief Initialize as valid MDCT handle 132 * 133 * \param hMdct handle of an allocated MDCT handle. 134 * \param overlap pointer to FIXP_DBL overlap buffer. 135 * \param overlapBufferSize size in FIXP_DBLs of the given overlap buffer. 136 * \return void 137 */ 138void mdct_init( H_MDCT hMdct, 139 FIXP_DBL *overlap, 140 INT overlapBufferSize ); 141 142/** 143 * \brief perform MDCT transform (time domain to frequency domain) with given parameters. 144 * 145 * \param hMdct handle of an allocated MDCT handle. 146 * \param spectrum pointer to where the resulting MDCT spectrum will be stored into. 147 * \param scalefactor pointer to the input scale shift value. Updated accordingly on return. 148 * \param input pointer to input time domain signal 149 * \param tl transformation length. 150 * \param nr right window slope offset (amount of window coefficients assumed to be 1.0) 151 * \param fr right overlap window slope length 152 * \param wrs pointer to the right side overlap window coefficients. 153 * \return number of input samples processed. 154 */ 155INT mdct_block( 156 H_MDCT hMdct, 157 FIXP_DBL *spectrum, 158 INT *scalefactor, 159 INT_PCM *input, 160 INT tl, 161 INT nr, 162 INT fr, 163 const FIXP_WTB *wrs ); 164 165 166/** 167 * \brief add/multiply 2/N transform gain and MPEG4 part 3 defined output gain (see definition 168 * of MDCT_OUTPUT_GAIN) to given mantissa factor and exponent. 169 * \param pGain pointer to the mantissa of a gain factor to be applied to IMDCT data. 170 * \param pExponent pointer to the exponent of a gain factor to be applied to IMDCT data. 171 * \param tl length of the IMDCT where the gain *pGain * (2 ^ *pExponent) will be applied to. 172 */ 173void imdct_gain( 174 FIXP_DBL *pGain, 175 int *pExponent, 176 int tl 177 ); 178 179/** 180 * \brief drain buffered output samples into given buffer. Changes the MDCT state. 181 */ 182INT imdct_drain( 183 H_MDCT hMdct, 184 FIXP_DBL * pTimeData, 185 INT nrSamplesRoom 186 ); 187 188 189/** 190 * \brief Copy overlap time domain data to given buffer. Does not change the MDCT state. 191 * \return number of actually copied samples (ov + nr). 192 */ 193INT imdct_copy_ov_and_nr( 194 H_MDCT hMdct, 195 FIXP_DBL * pTimeData, 196 INT nrSamples 197 ); 198 199/** 200 * \brief Adapt MDCT parameters for non-matching window slopes. 201 * \param hMdct handle of an allocated MDCT handle. 202 * \param pfl pointer to left overlap window side length. 203 * \param pnl pointer to length of the left n part of the window. 204 * \param tl transform length. 205 * \param wls pointer to the left side overlap window coefficients. 206 * \param noOutSamples desired number of output samples. 207 */ 208void imdct_adapt_parameters(H_MDCT hMdct, int *pfl, int *pnl, int tl, const FIXP_WTP *wls, int noOutSamples); 209 210/** 211 * \brief perform several inverse MDCT transforms (frequency domain to time domain) with given parameters. 212 * 213 * \param hMdct handle of an allocated MDCT handle. 214 * \param output pointer to where the output time domain signal will be stored into. 215 * \param stride the stride factor for accessing time domain samples in output. 216 * \param spectrum pointer to the input MDCT spectra. 217 * \param scalefactors scale shift values of the input spectrum. 218 * \param nSpec number of MDCT spectrums. 219 * \param noOutSamples desired number of output samples. 220 * \param tl transform length. 221 * \param wls pointer to the left side overlap window coefficients. 222 * \param fl left overlap window side length. 223 * \param wrs pointer to the right side overlap window coefficients of all individual IMDCTs. 224 * \param fr right overlap window side length of all individual IMDCTs. 225 * \param gain factor to apply to output samples (if != 0). 226 * \return number of output samples returned. 227 */ 228INT imdct_block( 229 H_MDCT hMdct, 230 FIXP_DBL *output, 231 FIXP_DBL *spectrum, 232 const SHORT scalefactor[], 233 const INT nSpec, 234 const INT noOutSamples, 235 const INT tl, 236 const FIXP_WTP *wls, 237 INT fl, 238 const FIXP_WTP *wrs, 239 const INT fr, 240 FIXP_DBL gain ); 241 242 243#endif /* __MDCT_H__ */ 244