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Diffstat (limited to 'libPCMutils/include/limiter.h')
| -rw-r--r-- | libPCMutils/include/limiter.h | 342 |
1 files changed, 195 insertions, 147 deletions
diff --git a/libPCMutils/include/limiter.h b/libPCMutils/include/limiter.h index 0d3d701..fab7226 100644 --- a/libPCMutils/include/limiter.h +++ b/libPCMutils/include/limiter.h @@ -1,74 +1,85 @@ - -/* ----------------------------------------------------------------------------------------------------------- +/* ----------------------------------------------------------------------------- Software License for The Fraunhofer FDK AAC Codec Library for Android -© Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V. - All rights reserved. +© Copyright 1995 - 2018 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. +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: +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 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 +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. +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. +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." +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. +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. +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. +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 @@ -79,34 +90,53 @@ Am Wolfsmantel 33 www.iis.fraunhofer.de/amm amm-info@iis.fraunhofer.de ------------------------------------------------------------------------------------------------------------ */ +----------------------------------------------------------------------------- */ -/************************ FDK PCM postprocessor module ********************* +/**************************** PCM utility library ****************************** Author(s): Matthias Neusinger + Description: Hard limiter for clipping prevention *******************************************************************************/ -#ifndef _LIMITER_H_ -#define _LIMITER_H_ - +#ifndef LIMITER_H +#define LIMITER_H #include "common_fix.h" +#include "FDK_audio.h" -#define TDL_ATTACK_DEFAULT_MS (15) /* default attack time in ms */ -#define TDL_RELEASE_DEFAULT_MS (50) /* default release time in ms */ - -#define TDL_GAIN_SCALING (15) /* scaling of gain value. */ +#define TDL_ATTACK_DEFAULT_MS (15) /* default attack time in ms */ +#define TDL_RELEASE_DEFAULT_MS (50) /* default release time in ms */ +#define TDL_GAIN_SCALING (15) /* scaling of gain value. */ #ifdef __cplusplus extern "C" { #endif +struct TDLimiter { + unsigned int attack; + FIXP_DBL attackConst, releaseConst; + unsigned int attackMs, releaseMs, maxAttackMs; + FIXP_DBL threshold; + unsigned int channels, maxChannels; + UINT sampleRate, maxSampleRate; + FIXP_DBL cor, max; + FIXP_DBL* maxBuf; + FIXP_DBL* delayBuf; + unsigned int maxBufIdx, delayBufIdx; + FIXP_DBL smoothState0; + FIXP_DBL minGain; + + FIXP_DBL additionalGainPrev; + FIXP_DBL additionalGainFilterState; + FIXP_DBL additionalGainFilterState1; +}; typedef enum { TDLIMIT_OK = 0, + TDLIMIT_UNKNOWN = -1, __error_codes_start = -100, @@ -119,115 +149,133 @@ typedef enum { struct TDLimiter; typedef struct TDLimiter* TDLimiterPtr; -/****************************************************************************** -* createLimiter * -* maxAttackMs: maximum and initial attack/lookahead time in milliseconds * -* releaseMs: release time in milliseconds (90% time constant) * -* threshold: limiting threshold * -* maxChannels: maximum and initial number of channels * -* maxSampleRate: maximum and initial sampling rate in Hz * -* returns: limiter handle * -******************************************************************************/ -TDLimiterPtr createLimiter(unsigned int maxAttackMs, - unsigned int releaseMs, - INT_PCM threshold, - unsigned int maxChannels, - unsigned int maxSampleRate); +#define PCM_LIM LONG +#define FIXP_DBL2PCM_LIM(x) (x) +#define PCM_LIM2FIXP_DBL(x) (x) +#define PCM_LIM_BITS 32 +#define FIXP_PCM_LIM FIXP_DBL +#define SAMPLE_BITS_LIM DFRACT_BITS /****************************************************************************** -* resetLimiter * -* limiter: limiter handle * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR resetLimiter(TDLimiterPtr limiter); - + * pcmLimiter_Reset * + * limiter: limiter handle * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_Reset(TDLimiterPtr limiter); /****************************************************************************** -* destroyLimiter * -* limiter: limiter handle * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR destroyLimiter(TDLimiterPtr limiter); + * pcmLimiter_Destroy * + * limiter: limiter handle * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_Destroy(TDLimiterPtr limiter); /****************************************************************************** -* applyLimiter * -* limiter: limiter handle * -* pGain : pointer to gains to be applied to the signal before limiting, * -* which are downscaled by TDL_GAIN_SCALING bit. * -* These gains are delayed by gain_delay, and smoothed. * -* Smoothing is done by a butterworth lowpass filter with a cutoff * -* frequency which is fixed with respect to the sampling rate. * -* It is a substitute for the smoothing due to windowing and * -* overlap/add, if a gain is applied in frequency domain. * -* gain_scale: pointer to scaling exponents to be applied to the signal before * -* limiting, without delay and without smoothing * -* gain_size: number of elements in pGain, currently restricted to 1 * -* gain_delay: delay [samples] with which the gains in pGain shall be applied * -* gain_delay <= nSamples * -* samples: input/output buffer containing interleaved samples * -* precision of output will be DFRACT_BITS-TDL_GAIN_SCALING bits * -* nSamples: number of samples per channel * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR applyLimiter(TDLimiterPtr limiter, - INT_PCM* samples, - FIXP_DBL* pGain, - const INT* gain_scale, - const UINT gain_size, - const UINT gain_delay, - const UINT nSamples); + * pcmLimiter_GetDelay * + * limiter: limiter handle * + * returns: exact delay caused by the limiter in samples per channel * + ******************************************************************************/ +unsigned int pcmLimiter_GetDelay(TDLimiterPtr limiter); /****************************************************************************** -* getLimiterDelay * -* limiter: limiter handle * -* returns: exact delay caused by the limiter in samples * -******************************************************************************/ -unsigned int getLimiterDelay(TDLimiterPtr limiter); + * pcmLimiter_GetMaxGainReduction * + * limiter: limiter handle * + * returns: maximum gain reduction in last processed block in dB * + ******************************************************************************/ +INT pcmLimiter_GetMaxGainReduction(TDLimiterPtr limiter); /****************************************************************************** -* setLimiterNChannels * -* limiter: limiter handle * -* nChannels: number of channels ( <= maxChannels specified on create) * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR setLimiterNChannels(TDLimiterPtr limiter, unsigned int nChannels); + * pcmLimiter_SetNChannels * + * limiter: limiter handle * + * nChannels: number of channels ( <= maxChannels specified on create) * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_SetNChannels(TDLimiterPtr limiter, + unsigned int nChannels); /****************************************************************************** -* setLimiterSampleRate * -* limiter: limiter handle * -* sampleRate: sampling rate in Hz ( <= maxSampleRate specified on create) * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR setLimiterSampleRate(TDLimiterPtr limiter, unsigned int sampleRate); + * pcmLimiter_SetSampleRate * + * limiter: limiter handle * + * sampleRate: sampling rate in Hz ( <= maxSampleRate specified on create) * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_SetSampleRate(TDLimiterPtr limiter, UINT sampleRate); /****************************************************************************** -* setLimiterAttack * -* limiter: limiter handle * -* attackMs: attack time in ms ( <= maxAttackMs specified on create) * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR setLimiterAttack(TDLimiterPtr limiter, unsigned int attackMs); + * pcmLimiter_SetAttack * + * limiter: limiter handle * + * attackMs: attack time in ms ( <= maxAttackMs specified on create) * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_SetAttack(TDLimiterPtr limiter, + unsigned int attackMs); /****************************************************************************** -* setLimiterRelease * -* limiter: limiter handle * -* releaseMs: release time in ms * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR setLimiterRelease(TDLimiterPtr limiter, unsigned int releaseMs); + * pcmLimiter_SetRelease * + * limiter: limiter handle * + * releaseMs: release time in ms * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_SetRelease(TDLimiterPtr limiter, + unsigned int releaseMs); /****************************************************************************** -* setLimiterThreshold * -* limiter: limiter handle * -* threshold: limiter threshold * -* returns: error code * -******************************************************************************/ -TDLIMITER_ERROR setLimiterThreshold(TDLimiterPtr limiter, INT_PCM threshold); + * pcmLimiter_GetLibInfo * + * info: pointer to an allocated and initialized LIB_INFO structure * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_GetLibInfo(LIB_INFO* info); #ifdef __cplusplus } #endif +/****************************************************************************** + * pcmLimiter_Create * + * maxAttackMs: maximum and initial attack/lookahead time in milliseconds * + * releaseMs: release time in milliseconds (90% time constant) * + * threshold: limiting threshold * + * maxChannels: maximum and initial number of channels * + * maxSampleRate: maximum and initial sampling rate in Hz * + * returns: limiter handle * + ******************************************************************************/ +TDLimiterPtr pcmLimiter_Create(unsigned int maxAttackMs, unsigned int releaseMs, + FIXP_DBL threshold, unsigned int maxChannels, + UINT maxSampleRate); -#endif //#ifndef _LIMITER_H_ +/****************************************************************************** + * pcmLimiter_SetThreshold * + * limiter: limiter handle * + * threshold: limiter threshold * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_SetThreshold(TDLimiterPtr limiter, + FIXP_DBL threshold); + +/****************************************************************************** + * pcmLimiter_Apply * + * limiter: limiter handle * + * pGain : pointer to gains to be applied to the signal before limiting, * + * which are downscaled by TDL_GAIN_SCALING bit. * + * These gains are delayed by gain_delay, and smoothed. * + * Smoothing is done by a butterworth lowpass filter with a cutoff * + * frequency which is fixed with respect to the sampling rate. * + * It is a substitute for the smoothing due to windowing and * + * overlap/add, if a gain is applied in frequency domain. * + * gain_scale: pointer to scaling exponents to be applied to the signal before * + * limiting, without delay and without smoothing * + * gain_size: number of elements in pGain, currently restricted to 1 * + * gain_delay: delay [samples] with which the gains in pGain shall be applied * + * gain_delay <= nSamples * + * samples: input/output buffer containing interleaved samples * + * precision of output will be DFRACT_BITS-TDL_GAIN_SCALING bits * + * nSamples: number of samples per channel * + * returns: error code * + ******************************************************************************/ +TDLIMITER_ERROR pcmLimiter_Apply(TDLimiterPtr limiter, PCM_LIM* samplesIn, + INT_PCM* samplesOut, FIXP_DBL* pGain, + const INT* gain_scale, const UINT gain_size, + const UINT gain_delay, const UINT nSamples); + +#endif /* #ifndef LIMITER_H */ |