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/************************ FDK PCM postprocessor module ********************* 85 86 Author(s): Matthias Neusinger 87 Description: Hard limiter for clipping prevention 88 89*******************************************************************************/ 90 91#ifndef _LIMITER_H_ 92#define _LIMITER_H_ 93 94 95#include "common_fix.h" 96 97#define TDL_ATTACK_DEFAULT_MS (15) /* default attack time in ms */ 98#define TDL_RELEASE_DEFAULT_MS (50) /* default release time in ms */ 99 100#define TDL_GAIN_SCALING (15) /* scaling of gain value. */ 101 102 103#ifdef __cplusplus 104extern "C" { 105#endif 106 107 108typedef enum { 109 TDLIMIT_OK = 0, 110 111 __error_codes_start = -100, 112 113 TDLIMIT_INVALID_HANDLE, 114 TDLIMIT_INVALID_PARAMETER, 115 116 __error_codes_end 117} TDLIMITER_ERROR; 118 119struct TDLimiter; 120typedef struct TDLimiter* TDLimiterPtr; 121 122/****************************************************************************** 123* createLimiter * 124* maxAttackMs: maximum and initial attack/lookahead time in milliseconds * 125* releaseMs: release time in milliseconds (90% time constant) * 126* threshold: limiting threshold * 127* maxChannels: maximum and initial number of channels * 128* maxSampleRate: maximum and initial sampling rate in Hz * 129* returns: limiter handle * 130******************************************************************************/ 131TDLimiterPtr createLimiter(unsigned int maxAttackMs, 132 unsigned int releaseMs, 133 INT_PCM threshold, 134 unsigned int maxChannels, 135 unsigned int maxSampleRate); 136 137 138/****************************************************************************** 139* resetLimiter * 140* limiter: limiter handle * 141* returns: error code * 142******************************************************************************/ 143TDLIMITER_ERROR resetLimiter(TDLimiterPtr limiter); 144 145 146/****************************************************************************** 147* destroyLimiter * 148* limiter: limiter handle * 149* returns: error code * 150******************************************************************************/ 151TDLIMITER_ERROR destroyLimiter(TDLimiterPtr limiter); 152 153/****************************************************************************** 154* applyLimiter * 155* limiter: limiter handle * 156* pGain : pointer to gains to be applied to the signal before limiting, * 157* which are downscaled by TDL_GAIN_SCALING bit. * 158* These gains are delayed by gain_delay, and smoothed. * 159* Smoothing is done by a butterworth lowpass filter with a cutoff * 160* frequency which is fixed with respect to the sampling rate. * 161* It is a substitute for the smoothing due to windowing and * 162* overlap/add, if a gain is applied in frequency domain. * 163* gain_scale: pointer to scaling exponents to be applied to the signal before * 164* limiting, without delay and without smoothing * 165* gain_size: number of elements in pGain, currently restricted to 1 * 166* gain_delay: delay [samples] with which the gains in pGain shall be applied * 167* gain_delay <= nSamples * 168* samples: input/output buffer containing interleaved samples * 169* precision of output will be DFRACT_BITS-TDL_GAIN_SCALING bits * 170* nSamples: number of samples per channel * 171* returns: error code * 172******************************************************************************/ 173TDLIMITER_ERROR applyLimiter(TDLimiterPtr limiter, 174 INT_PCM* samples, 175 FIXP_DBL* pGain, 176 const INT* gain_scale, 177 const UINT gain_size, 178 const UINT gain_delay, 179 const UINT nSamples); 180 181/****************************************************************************** 182* getLimiterDelay * 183* limiter: limiter handle * 184* returns: exact delay caused by the limiter in samples * 185******************************************************************************/ 186unsigned int getLimiterDelay(TDLimiterPtr limiter); 187 188/****************************************************************************** 189* setLimiterNChannels * 190* limiter: limiter handle * 191* nChannels: number of channels ( <= maxChannels specified on create) * 192* returns: error code * 193******************************************************************************/ 194TDLIMITER_ERROR setLimiterNChannels(TDLimiterPtr limiter, unsigned int nChannels); 195 196/****************************************************************************** 197* setLimiterSampleRate * 198* limiter: limiter handle * 199* sampleRate: sampling rate in Hz ( <= maxSampleRate specified on create) * 200* returns: error code * 201******************************************************************************/ 202TDLIMITER_ERROR setLimiterSampleRate(TDLimiterPtr limiter, unsigned int sampleRate); 203 204/****************************************************************************** 205* setLimiterAttack * 206* limiter: limiter handle * 207* attackMs: attack time in ms ( <= maxAttackMs specified on create) * 208* returns: error code * 209******************************************************************************/ 210TDLIMITER_ERROR setLimiterAttack(TDLimiterPtr limiter, unsigned int attackMs); 211 212/****************************************************************************** 213* setLimiterRelease * 214* limiter: limiter handle * 215* releaseMs: release time in ms * 216* returns: error code * 217******************************************************************************/ 218TDLIMITER_ERROR setLimiterRelease(TDLimiterPtr limiter, unsigned int releaseMs); 219 220/****************************************************************************** 221* setLimiterThreshold * 222* limiter: limiter handle * 223* threshold: limiter threshold * 224* returns: error code * 225******************************************************************************/ 226TDLIMITER_ERROR setLimiterThreshold(TDLimiterPtr limiter, INT_PCM threshold); 227 228#ifdef __cplusplus 229} 230#endif 231 232 233#endif //#ifndef _LIMITER_H_ 234