1 /* ----------------------------------------------------------------------------- 2 Software License for The Fraunhofer FDK AAC Codec Library for Android 3 4 © Copyright 1995 - 2019 Fraunhofer-Gesellschaft zur Förderung der angewandten 5 Forschung e.V. All rights reserved. 6 7 1. INTRODUCTION 8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software 9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding 10 scheme for digital audio. This FDK AAC Codec software is intended to be used on 11 a wide variety of Android devices. 12 13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient 14 general perceptual audio codecs. AAC-ELD is considered the best-performing 15 full-bandwidth communications codec by independent studies and is widely 16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG 17 specifications. 18 19 Patent licenses for necessary patent claims for the FDK AAC Codec (including 20 those of Fraunhofer) may be obtained through Via Licensing 21 (www.vialicensing.com) or through the respective patent owners individually for 22 the purpose of encoding or decoding bit streams in products that are compliant 23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of 24 Android devices already license these patent claims through Via Licensing or 25 directly from the patent owners, and therefore FDK AAC Codec software may 26 already be covered under those patent licenses when it is used for those 27 licensed purposes only. 28 29 Commercially-licensed AAC software libraries, including floating-point versions 30 with enhanced sound quality, are also available from Fraunhofer. Users are 31 encouraged to check the Fraunhofer website for additional applications 32 information and documentation. 33 34 2. COPYRIGHT LICENSE 35 36 Redistribution and use in source and binary forms, with or without modification, 37 are permitted without payment of copyright license fees provided that you 38 satisfy the following conditions: 39 40 You must retain the complete text of this software license in redistributions of 41 the FDK AAC Codec or your modifications thereto in source code form. 42 43 You must retain the complete text of this software license in the documentation 44 and/or other materials provided with redistributions of the FDK AAC Codec or 45 your modifications thereto in binary form. You must make available free of 46 charge copies of the complete source code of the FDK AAC Codec and your 47 modifications thereto to recipients of copies in binary form. 48 49 The name of Fraunhofer may not be used to endorse or promote products derived 50 from this library without prior written permission. 51 52 You may not charge copyright license fees for anyone to use, copy or distribute 53 the FDK AAC Codec software or your modifications thereto. 54 55 Your modified versions of the FDK AAC Codec must carry prominent notices stating 56 that you changed the software and the date of any change. For modified versions 57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android" 58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK 59 AAC Codec Library for Android." 60 61 3. NO PATENT LICENSE 62 63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without 64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE. 65 Fraunhofer provides no warranty of patent non-infringement with respect to this 66 software. 67 68 You may use this FDK AAC Codec software or modifications thereto only for 69 purposes that are authorized by appropriate patent licenses. 70 71 4. DISCLAIMER 72 73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright 74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, 75 including but not limited to the implied warranties of merchantability and 76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, 78 or consequential damages, including but not limited to procurement of substitute 79 goods or services; loss of use, data, or profits, or business interruption, 80 however caused and on any theory of liability, whether in contract, strict 81 liability, or tort (including negligence), arising in any way out of the use of 82 this software, even if advised of the possibility of such damage. 83 84 5. CONTACT INFORMATION 85 86 Fraunhofer Institute for Integrated Circuits IIS 87 Attention: Audio and Multimedia Departments - FDK AAC LL 88 Am Wolfsmantel 33 89 91058 Erlangen, Germany 90 91 www.iis.fraunhofer.de/amm 92 amm-info@iis.fraunhofer.de 93 ----------------------------------------------------------------------------- */ 94 95 /**************************** PCM utility library ****************************** 96 97 Author(s): Matthias Neusinger 98 99 Description: Hard limiter for clipping prevention 100 101 *******************************************************************************/ 102 103 #ifndef LIMITER_H 104 #define LIMITER_H 105 106 #include "common_fix.h" 107 #include "FDK_audio.h" 108 109 #define TDL_ATTACK_DEFAULT_MS (15) /* default attack time in ms */ 110 #define TDL_RELEASE_DEFAULT_MS (50) /* default release time in ms */ 111 112 #ifdef __cplusplus 113 extern "C" { 114 #endif 115 116 struct TDLimiter { 117 unsigned int attack; 118 FIXP_DBL attackConst, releaseConst; 119 unsigned int attackMs, releaseMs, maxAttackMs; 120 FIXP_DBL threshold; 121 unsigned int channels, maxChannels; 122 UINT sampleRate, maxSampleRate; 123 FIXP_DBL cor, max; 124 FIXP_DBL* maxBuf; 125 FIXP_DBL* delayBuf; 126 unsigned int maxBufIdx, delayBufIdx; 127 FIXP_DBL smoothState0; 128 FIXP_DBL minGain; 129 INT scaling; 130 }; 131 132 typedef enum { 133 TDLIMIT_OK = 0, 134 TDLIMIT_UNKNOWN = -1, 135 136 __error_codes_start = -100, 137 138 TDLIMIT_INVALID_HANDLE, 139 TDLIMIT_INVALID_PARAMETER, 140 141 __error_codes_end 142 } TDLIMITER_ERROR; 143 144 struct TDLimiter; 145 typedef struct TDLimiter* TDLimiterPtr; 146 147 #define PCM_LIM LONG 148 #define FIXP_DBL2PCM_LIM(x) (x) 149 #define PCM_LIM2FIXP_DBL(x) (x) 150 #define PCM_LIM_BITS 32 151 #define FIXP_PCM_LIM FIXP_DBL 152 153 #define SAMPLE_BITS_LIM DFRACT_BITS 154 155 /****************************************************************************** 156 * pcmLimiter_Reset * 157 * limiter: limiter handle * 158 * returns: error code * 159 ******************************************************************************/ 160 TDLIMITER_ERROR pcmLimiter_Reset(TDLimiterPtr limiter); 161 162 /****************************************************************************** 163 * pcmLimiter_Destroy * 164 * limiter: limiter handle * 165 * returns: error code * 166 ******************************************************************************/ 167 TDLIMITER_ERROR pcmLimiter_Destroy(TDLimiterPtr limiter); 168 169 /****************************************************************************** 170 * pcmLimiter_GetDelay * 171 * limiter: limiter handle * 172 * returns: exact delay caused by the limiter in samples per channel * 173 ******************************************************************************/ 174 unsigned int pcmLimiter_GetDelay(TDLimiterPtr limiter); 175 176 /****************************************************************************** 177 * pcmLimiter_GetMaxGainReduction * 178 * limiter: limiter handle * 179 * returns: maximum gain reduction in last processed block in dB * 180 ******************************************************************************/ 181 INT pcmLimiter_GetMaxGainReduction(TDLimiterPtr limiter); 182 183 /****************************************************************************** 184 * pcmLimiter_SetNChannels * 185 * limiter: limiter handle * 186 * nChannels: number of channels ( <= maxChannels specified on create) * 187 * returns: error code * 188 ******************************************************************************/ 189 TDLIMITER_ERROR pcmLimiter_SetNChannels(TDLimiterPtr limiter, 190 unsigned int nChannels); 191 192 /****************************************************************************** 193 * pcmLimiter_SetSampleRate * 194 * limiter: limiter handle * 195 * sampleRate: sampling rate in Hz ( <= maxSampleRate specified on create) * 196 * returns: error code * 197 ******************************************************************************/ 198 TDLIMITER_ERROR pcmLimiter_SetSampleRate(TDLimiterPtr limiter, UINT sampleRate); 199 200 /****************************************************************************** 201 * pcmLimiter_SetAttack * 202 * limiter: limiter handle * 203 * attackMs: attack time in ms ( <= maxAttackMs specified on create) * 204 * returns: error code * 205 ******************************************************************************/ 206 TDLIMITER_ERROR pcmLimiter_SetAttack(TDLimiterPtr limiter, 207 unsigned int attackMs); 208 209 /****************************************************************************** 210 * pcmLimiter_SetRelease * 211 * limiter: limiter handle * 212 * releaseMs: release time in ms * 213 * returns: error code * 214 ******************************************************************************/ 215 TDLIMITER_ERROR pcmLimiter_SetRelease(TDLimiterPtr limiter, 216 unsigned int releaseMs); 217 218 /****************************************************************************** 219 * pcmLimiter_GetLibInfo * 220 * info: pointer to an allocated and initialized LIB_INFO structure * 221 * returns: error code * 222 ******************************************************************************/ 223 TDLIMITER_ERROR pcmLimiter_GetLibInfo(LIB_INFO* info); 224 225 #ifdef __cplusplus 226 } 227 #endif 228 229 /****************************************************************************** 230 * pcmLimiter_Create * 231 * maxAttackMs: maximum and initial attack/lookahead time in milliseconds * 232 * releaseMs: release time in milliseconds (90% time constant) * 233 * threshold: limiting threshold * 234 * maxChannels: maximum and initial number of channels * 235 * maxSampleRate: maximum and initial sampling rate in Hz * 236 * returns: limiter handle * 237 ******************************************************************************/ 238 TDLimiterPtr pcmLimiter_Create(unsigned int maxAttackMs, unsigned int releaseMs, 239 FIXP_DBL threshold, unsigned int maxChannels, 240 UINT maxSampleRate); 241 242 /****************************************************************************** 243 * pcmLimiter_SetThreshold * 244 * limiter: limiter handle * 245 * threshold: limiter threshold * 246 * returns: error code * 247 ******************************************************************************/ 248 TDLIMITER_ERROR pcmLimiter_SetThreshold(TDLimiterPtr limiter, 249 FIXP_DBL threshold); 250 251 /****************************************************************************** 252 * pcmLimiter_Apply * 253 * limiter: limiter handle * 254 * samplesIn: pointer to input buffer containing interleaved samples * 255 * samplesOut: pointer to output buffer containing interleaved samples * 256 * pGainPerSample: pointer to gains for each sample * 257 * scaling: scaling of output samples * 258 * nSamples: number of samples per channel * 259 * returns: error code * 260 ******************************************************************************/ 261 TDLIMITER_ERROR pcmLimiter_Apply(TDLimiterPtr limiter, PCM_LIM* samplesIn, 262 INT_PCM* samplesOut, FIXP_DBL* pGainPerSample, 263 const INT scaling, const UINT nSamples); 264 265 #endif /* #ifndef LIMITER_H */ 266