| |
| /* ----------------------------------------------------------------------------------------------------------- |
| Software License for The Fraunhofer FDK AAC Codec Library for Android |
| |
| © Copyright 1995 - 2012 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. |
| |
| 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: |
| |
| 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 |
| 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. |
| |
| 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." |
| |
| 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. |
| |
| 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. |
| |
| 5. CONTACT INFORMATION |
| |
| Fraunhofer Institute for Integrated Circuits IIS |
| Attention: Audio and Multimedia Departments - FDK AAC LL |
| Am Wolfsmantel 33 |
| 91058 Erlangen, Germany |
| |
| www.iis.fraunhofer.de/amm |
| amm-info@iis.fraunhofer.de |
| ----------------------------------------------------------------------------------------------------------- */ |
| |
| /*************************** Fraunhofer IIS FDK Tools ********************** |
| |
| Author(s): Manuel Jander, Josef Hoepfl |
| Description: MDCT routines |
| |
| ******************************************************************************/ |
| |
| #ifndef __MDCT_H__ |
| #define __MDCT_H__ |
| |
| |
| |
| #include "common_fix.h" |
| |
| #define MDCT_OUT_HEADROOM 2 /* Output additional headroom */ |
| #define MDCT_OUTPUT_SCALE (DFRACT_BITS-SAMPLE_BITS-MDCT_OUT_HEADROOM) |
| /* Refer to "Output word length" in ISO/IEC 14496-3:2008(E) 23.2.3.6 */ |
| #define MDCT_OUTPUT_GAIN 16 |
| |
| #if (SAMPLE_BITS == DFRACT_BITS) |
| #define IMDCT_SCALE(x) (INT_PCM)SATURATE_LEFT_SHIFT(x, -MDCT_OUTPUT_SCALE, SAMPLE_BITS) |
| #else |
| #define IMDCT_SCALE(x) (INT_PCM)SATURATE_RIGHT_SHIFT(x, MDCT_OUTPUT_SCALE, SAMPLE_BITS) |
| #endif |
| #define IMDCT_SCALE_DBL(x) (FIXP_DBL)(x) |
| |
| /** |
| * \brief MDCT persistent data |
| */ |
| typedef struct { |
| union { |
| FIXP_DBL *freq; |
| FIXP_DBL *time; |
| } overlap; /**< Pointer to overlap memory */ |
| |
| const FIXP_WTP *prev_wrs; /**< pointer to previous right window slope */ |
| int prev_tl; /**< previous tranform length */ |
| int prev_nr; /**< previous right window offset */ |
| int prev_fr; /**< previous right window slope length */ |
| int ov_offset; /**< overlap time data fill level */ |
| int ov_size; /**< Overlap buffer size in words */ |
| |
| } mdct_t; |
| |
| typedef mdct_t* H_MDCT; |
| |
| /** |
| * \brief Initialize as valid MDCT handle |
| * |
| * \param hMdct handle of an allocated MDCT handle. |
| * \param overlap pointer to FIXP_DBL overlap buffer. |
| * \param overlapBufferSize size in FIXP_DBLs of the given overlap buffer. |
| * \return void |
| */ |
| void mdct_init( H_MDCT hMdct, |
| FIXP_DBL *overlap, |
| INT overlapBufferSize ); |
| |
| /** |
| * \brief perform MDCT transform (time domain to frequency domain) with given parameters. |
| * |
| * \param hMdct handle of an allocated MDCT handle. |
| * \param spectrum pointer to where the resulting MDCT spectrum will be stored into. |
| * \param scalefactor pointer to the input scale shift value. Updated accordingly on return. |
| * \param input pointer to input time domain signal |
| * \param tl transformation length. |
| * \param nr right window slope offset (amount of window coefficients assumed to be 1.0) |
| * \param fr right overlap window slope length |
| * \param wrs pointer to the right side overlap window coefficients. |
| * \return number of input samples processed. |
| */ |
| INT mdct_block( |
| H_MDCT hMdct, |
| FIXP_DBL *spectrum, |
| INT *scalefactor, |
| INT_PCM *input, |
| INT tl, |
| INT nr, |
| INT fr, |
| const FIXP_WTB *wrs ); |
| |
| |
| /** |
| * \brief add/multiply 2/N transform gain and MPEG4 part 3 defined output gain (see definition |
| * of MDCT_OUTPUT_GAIN) to given mantissa factor and exponent. |
| * \param pGain pointer to the mantissa of a gain factor to be applied to IMDCT data. |
| * \param pExponent pointer to the exponent of a gain factor to be applied to IMDCT data. |
| * \param tl length of the IMDCT where the gain *pGain * (2 ^ *pExponent) will be applied to. |
| */ |
| void imdct_gain( |
| FIXP_DBL *pGain, |
| int *pExponent, |
| int tl |
| ); |
| |
| /** |
| * \brief drain buffered output samples into given buffer. Changes the MDCT state. |
| */ |
| INT imdct_drain( |
| H_MDCT hMdct, |
| FIXP_DBL * pTimeData, |
| INT nrSamplesRoom |
| ); |
| |
| |
| /** |
| * \brief Copy overlap time domain data to given buffer. Does not change the MDCT state. |
| * \return number of actually copied samples (ov + nr). |
| */ |
| INT imdct_copy_ov_and_nr( |
| H_MDCT hMdct, |
| FIXP_DBL * pTimeData, |
| INT nrSamples |
| ); |
| |
| /** |
| * \brief Adapt MDCT parameters for non-matching window slopes. |
| * \param hMdct handle of an allocated MDCT handle. |
| * \param pfl pointer to left overlap window side length. |
| * \param pnl pointer to length of the left n part of the window. |
| * \param tl transform length. |
| * \param wls pointer to the left side overlap window coefficients. |
| * \param noOutSamples desired number of output samples. |
| */ |
| void imdct_adapt_parameters(H_MDCT hMdct, int *pfl, int *pnl, int tl, const FIXP_WTP *wls, int noOutSamples); |
| |
| /** |
| * \brief perform several inverse MDCT transforms (frequency domain to time domain) with given parameters. |
| * |
| * \param hMdct handle of an allocated MDCT handle. |
| * \param output pointer to where the output time domain signal will be stored into. |
| * \param stride the stride factor for accessing time domain samples in output. |
| * \param spectrum pointer to the input MDCT spectra. |
| * \param scalefactors scale shift values of the input spectrum. |
| * \param nSpec number of MDCT spectrums. |
| * \param noOutSamples desired number of output samples. |
| * \param tl transform length. |
| * \param wls pointer to the left side overlap window coefficients. |
| * \param fl left overlap window side length. |
| * \param wrs pointer to the right side overlap window coefficients of all individual IMDCTs. |
| * \param fr right overlap window side length of all individual IMDCTs. |
| * \param gain factor to apply to output samples (if != 0). |
| * \return number of output samples returned. |
| */ |
| INT imdct_block( |
| H_MDCT hMdct, |
| FIXP_DBL *output, |
| FIXP_DBL *spectrum, |
| const SHORT scalefactor[], |
| const INT nSpec, |
| const INT noOutSamples, |
| const INT tl, |
| const FIXP_WTP *wls, |
| INT fl, |
| const FIXP_WTP *wrs, |
| const INT fr, |
| FIXP_DBL gain ); |
| |
| |
| #endif /* __MDCT_H__ */ |