mirror of https://github.com/mstorsjo/fdk-aac.git
406 lines
16 KiB
C
406 lines
16 KiB
C
/* -----------------------------------------------------------------------------
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Software License for The Fraunhofer FDK AAC Codec Library for Android
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© Copyright 1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
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Forschung e.V. All rights reserved.
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1. INTRODUCTION
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The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
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that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
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scheme for digital audio. This FDK AAC Codec software is intended to be used on
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a wide variety of Android devices.
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AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
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general perceptual audio codecs. AAC-ELD is considered the best-performing
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full-bandwidth communications codec by independent studies and is widely
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deployed. AAC has been standardized by ISO and IEC as part of the MPEG
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specifications.
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Patent licenses for necessary patent claims for the FDK AAC Codec (including
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those of Fraunhofer) may be obtained through Via Licensing
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(www.vialicensing.com) or through the respective patent owners individually for
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the purpose of encoding or decoding bit streams in products that are compliant
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with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
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Android devices already license these patent claims through Via Licensing or
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directly from the patent owners, and therefore FDK AAC Codec software may
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already be covered under those patent licenses when it is used for those
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licensed purposes only.
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Commercially-licensed AAC software libraries, including floating-point versions
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with enhanced sound quality, are also available from Fraunhofer. Users are
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encouraged to check the Fraunhofer website for additional applications
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information and documentation.
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2. COPYRIGHT LICENSE
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Redistribution and use in source and binary forms, with or without modification,
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are permitted without payment of copyright license fees provided that you
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satisfy the following conditions:
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You must retain the complete text of this software license in redistributions of
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the FDK AAC Codec or your modifications thereto in source code form.
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You must retain the complete text of this software license in the documentation
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and/or other materials provided with redistributions of the FDK AAC Codec or
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your modifications thereto in binary form. You must make available free of
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charge copies of the complete source code of the FDK AAC Codec and your
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modifications thereto to recipients of copies in binary form.
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The name of Fraunhofer may not be used to endorse or promote products derived
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from this library without prior written permission.
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You may not charge copyright license fees for anyone to use, copy or distribute
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the FDK AAC Codec software or your modifications thereto.
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Your modified versions of the FDK AAC Codec must carry prominent notices stating
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that you changed the software and the date of any change. For modified versions
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of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
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must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
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AAC Codec Library for Android."
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3. NO PATENT LICENSE
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NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
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limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
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Fraunhofer provides no warranty of patent non-infringement with respect to this
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software.
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You may use this FDK AAC Codec software or modifications thereto only for
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purposes that are authorized by appropriate patent licenses.
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4. DISCLAIMER
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This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
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holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
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including but not limited to the implied warranties of merchantability and
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fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
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CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
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or consequential damages, including but not limited to procurement of substitute
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goods or services; loss of use, data, or profits, or business interruption,
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however caused and on any theory of liability, whether in contract, strict
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liability, or tort (including negligence), arising in any way out of the use of
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this software, even if advised of the possibility of such damage.
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5. CONTACT INFORMATION
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Fraunhofer Institute for Integrated Circuits IIS
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Attention: Audio and Multimedia Departments - FDK AAC LL
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Am Wolfsmantel 33
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91058 Erlangen, Germany
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www.iis.fraunhofer.de/amm
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amm-info@iis.fraunhofer.de
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----------------------------------------------------------------------------- */
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/******************* Library for basic calculation routines ********************
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Author(s): Markus Lohwasser, Josef Hoepfl, Manuel Jander
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Description: QMF filterbank
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*******************************************************************************/
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#ifndef QMF_PCM_H
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#define QMF_PCM_H
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/*
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All Synthesis functions dependent on datatype INT_PCM_QMFOUT
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Should only be included by qmf.cpp, but not compiled separately, please
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exclude compilation from project, if done otherwise. Is optional included
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twice to duplicate all functions with two different pre-definitions, as:
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#define INT_PCM_QMFOUT LONG
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and ...
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#define INT_PCM_QMFOUT SHORT
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needed to run QMF synthesis in both 16bit and 32bit sample output format.
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*/
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#define QSSCALE (0)
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#define FX_DBL2FX_QSS(x) (x)
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#define FX_QSS2FX_DBL(x) (x)
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/*!
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\brief Perform Synthesis Prototype Filtering on a single slot of input data.
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The filter takes 2 * qmf->no_channels of input data and
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generates qmf->no_channels time domain output samples.
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*/
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/* static */
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#ifndef FUNCTION_qmfSynPrototypeFirSlot
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void qmfSynPrototypeFirSlot(
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#else
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void qmfSynPrototypeFirSlot_fallback(
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#endif
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HANDLE_QMF_FILTER_BANK qmf,
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FIXP_DBL *RESTRICT realSlot, /*!< Input: Pointer to real Slot */
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FIXP_DBL *RESTRICT imagSlot, /*!< Input: Pointer to imag Slot */
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INT_PCM_QMFOUT *RESTRICT timeOut, /*!< Time domain data */
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int stride) {
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FIXP_QSS *FilterStates = (FIXP_QSS *)qmf->FilterStates;
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int no_channels = qmf->no_channels;
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const FIXP_PFT *p_Filter = qmf->p_filter;
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int p_stride = qmf->p_stride;
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int j;
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FIXP_QSS *RESTRICT sta = FilterStates;
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const FIXP_PFT *RESTRICT p_flt, *RESTRICT p_fltm;
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int scale = (DFRACT_BITS - SAMPLE_BITS_QMFOUT) - 1 - qmf->outScalefactor -
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qmf->outGain_e;
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p_flt =
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p_Filter + p_stride * QMF_NO_POLY; /* 5th of 330 */
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p_fltm = p_Filter + (qmf->FilterSize / 2) -
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p_stride * QMF_NO_POLY; /* 5 + (320 - 2*5) = 315th of 330 */
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FIXP_SGL gain = FX_DBL2FX_SGL(qmf->outGain_m);
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FIXP_DBL rnd_val = 0;
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if (scale > 0) {
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if (scale < (DFRACT_BITS - 1))
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rnd_val = FIXP_DBL(1 << (scale - 1));
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else
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scale = (DFRACT_BITS - 1);
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} else {
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scale = fMax(scale, -(DFRACT_BITS - 1));
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}
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for (j = no_channels - 1; j >= 0; j--) {
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FIXP_DBL imag = imagSlot[j]; /* no_channels-1 .. 0 */
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FIXP_DBL real = realSlot[j]; /* no_channels-1 .. 0 */
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{
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INT_PCM_QMFOUT tmp;
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FIXP_DBL Are = fMultAddDiv2(FX_QSS2FX_DBL(sta[0]), p_fltm[0], real);
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/* This PCM formatting performs:
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- multiplication with 16-bit gain, if not -1.0f
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- rounding, if shift right is applied
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- apply shift left (or right) with saturation to 32 (or 16) bits
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- store output with --stride in 32 (or 16) bit format
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*/
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if (gain != (FIXP_SGL)(-32768)) /* -1.0f */
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{
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Are = fMult(Are, gain);
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}
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if (scale >= 0) {
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FDK_ASSERT(
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Are <=
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(Are + rnd_val)); /* Round-addition must not overflow, might be
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equal for rnd_val=0 */
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tmp = (INT_PCM_QMFOUT)(
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SATURATE_RIGHT_SHIFT(Are + rnd_val, scale, SAMPLE_BITS_QMFOUT));
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} else {
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tmp = (INT_PCM_QMFOUT)(
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SATURATE_LEFT_SHIFT(Are, -scale, SAMPLE_BITS_QMFOUT));
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}
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{ timeOut[(j)*stride] = tmp; }
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}
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sta[0] = FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[1]), p_flt[4], imag));
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sta[1] =
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FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[2]), p_fltm[1], real));
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sta[2] = FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[3]), p_flt[3], imag));
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sta[3] =
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FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[4]), p_fltm[2], real));
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sta[4] = FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[5]), p_flt[2], imag));
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sta[5] =
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FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[6]), p_fltm[3], real));
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sta[6] = FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[7]), p_flt[1], imag));
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sta[7] =
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FX_DBL2FX_QSS(fMultAddDiv2(FX_QSS2FX_DBL(sta[8]), p_fltm[4], real));
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sta[8] = FX_DBL2FX_QSS(fMultDiv2(p_flt[0], imag));
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p_flt += (p_stride * QMF_NO_POLY);
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p_fltm -= (p_stride * QMF_NO_POLY);
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sta += 9; // = (2*QMF_NO_POLY-1);
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}
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}
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#ifndef FUNCTION_qmfSynPrototypeFirSlot_NonSymmetric
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/*!
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\brief Perform Synthesis Prototype Filtering on a single slot of input data.
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The filter takes 2 * qmf->no_channels of input data and
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generates qmf->no_channels time domain output samples.
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*/
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static void qmfSynPrototypeFirSlot_NonSymmetric(
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HANDLE_QMF_FILTER_BANK qmf,
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FIXP_DBL *RESTRICT realSlot, /*!< Input: Pointer to real Slot */
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FIXP_DBL *RESTRICT imagSlot, /*!< Input: Pointer to imag Slot */
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INT_PCM_QMFOUT *RESTRICT timeOut, /*!< Time domain data */
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int stride) {
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FIXP_QSS *FilterStates = (FIXP_QSS *)qmf->FilterStates;
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int no_channels = qmf->no_channels;
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const FIXP_PFT *p_Filter = qmf->p_filter;
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int p_stride = qmf->p_stride;
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int j;
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FIXP_QSS *RESTRICT sta = FilterStates;
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const FIXP_PFT *RESTRICT p_flt, *RESTRICT p_fltm;
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int scale = (DFRACT_BITS - SAMPLE_BITS_QMFOUT) - 1 - qmf->outScalefactor -
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qmf->outGain_e;
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p_flt = p_Filter; /*!< Pointer to first half of filter coefficients */
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p_fltm =
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&p_flt[qmf->FilterSize / 2]; /* at index 320, overall 640 coefficients */
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FIXP_SGL gain = FX_DBL2FX_SGL(qmf->outGain_m);
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FIXP_DBL rnd_val = (FIXP_DBL)0;
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if (scale > 0) {
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if (scale < (DFRACT_BITS - 1))
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rnd_val = FIXP_DBL(1 << (scale - 1));
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else
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scale = (DFRACT_BITS - 1);
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} else {
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scale = fMax(scale, -(DFRACT_BITS - 1));
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}
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for (j = no_channels - 1; j >= 0; j--) {
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FIXP_DBL imag = imagSlot[j]; /* no_channels-1 .. 0 */
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FIXP_DBL real = realSlot[j]; /* no_channels-1 .. 0 */
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{
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INT_PCM_QMFOUT tmp;
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FIXP_DBL Are = sta[0] + FX_DBL2FX_QSS(fMultDiv2(p_fltm[4], real));
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/* This PCM formatting performs:
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- multiplication with 16-bit gain, if not -1.0f
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- rounding, if shift right is applied
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- apply shift left (or right) with saturation to 32 (or 16) bits
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- store output with --stride in 32 (or 16) bit format
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*/
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if (gain != (FIXP_SGL)(-32768)) /* -1.0f */
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{
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Are = fMult(Are, gain);
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}
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if (scale > 0) {
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FDK_ASSERT(Are <
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(Are + rnd_val)); /* Round-addition must not overflow */
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tmp = (INT_PCM_QMFOUT)(
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SATURATE_RIGHT_SHIFT(Are + rnd_val, scale, SAMPLE_BITS_QMFOUT));
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} else {
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tmp = (INT_PCM_QMFOUT)(
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SATURATE_LEFT_SHIFT(Are, -scale, SAMPLE_BITS_QMFOUT));
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}
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timeOut[j * stride] = tmp;
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}
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sta[0] = sta[1] + FX_DBL2FX_QSS(fMultDiv2(p_flt[4], imag));
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sta[1] = sta[2] + FX_DBL2FX_QSS(fMultDiv2(p_fltm[3], real));
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sta[2] = sta[3] + FX_DBL2FX_QSS(fMultDiv2(p_flt[3], imag));
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sta[3] = sta[4] + FX_DBL2FX_QSS(fMultDiv2(p_fltm[2], real));
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sta[4] = sta[5] + FX_DBL2FX_QSS(fMultDiv2(p_flt[2], imag));
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sta[5] = sta[6] + FX_DBL2FX_QSS(fMultDiv2(p_fltm[1], real));
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sta[6] = sta[7] + FX_DBL2FX_QSS(fMultDiv2(p_flt[1], imag));
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sta[7] = sta[8] + FX_DBL2FX_QSS(fMultDiv2(p_fltm[0], real));
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sta[8] = FX_DBL2FX_QSS(fMultDiv2(p_flt[0], imag));
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p_flt += (p_stride * QMF_NO_POLY);
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p_fltm += (p_stride * QMF_NO_POLY);
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sta += 9; // = (2*QMF_NO_POLY-1);
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}
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}
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#endif /* FUNCTION_qmfSynPrototypeFirSlot_NonSymmetric */
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void qmfSynthesisFilteringSlot(HANDLE_QMF_FILTER_BANK synQmf,
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const FIXP_DBL *realSlot,
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const FIXP_DBL *imagSlot,
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const int scaleFactorLowBand,
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const int scaleFactorHighBand,
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INT_PCM_QMFOUT *timeOut, const int stride,
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FIXP_DBL *pWorkBuffer) {
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if (!(synQmf->flags & QMF_FLAG_LP))
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qmfInverseModulationHQ(synQmf, realSlot, imagSlot, scaleFactorLowBand,
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scaleFactorHighBand, pWorkBuffer);
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else {
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if (synQmf->flags & QMF_FLAG_CLDFB) {
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qmfInverseModulationLP_odd(synQmf, realSlot, scaleFactorLowBand,
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scaleFactorHighBand, pWorkBuffer);
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} else {
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qmfInverseModulationLP_even(synQmf, realSlot, scaleFactorLowBand,
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scaleFactorHighBand, pWorkBuffer);
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}
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}
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if (synQmf->flags & QMF_FLAG_NONSYMMETRIC) {
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qmfSynPrototypeFirSlot_NonSymmetric(synQmf, pWorkBuffer,
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pWorkBuffer + synQmf->no_channels,
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timeOut, stride);
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} else {
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qmfSynPrototypeFirSlot(synQmf, pWorkBuffer,
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pWorkBuffer + synQmf->no_channels, timeOut, stride);
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}
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}
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/*!
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*
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* \brief Perform complex-valued subband synthesis of the
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* low band and the high band and store the
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* time domain data in timeOut
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*
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* First step: Calculate the proper scaling factor of current
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* spectral data in qmfReal/qmfImag, old spectral data in the overlap
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* range and filter states.
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*
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* Second step: Perform Frequency-to-Time mapping with inverse
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* Modulation slot-wise.
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*
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* Third step: Perform FIR-filter slot-wise. To save space for filter
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* states, the MAC operations are executed directly on the filter states
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* instead of accumulating several products in the accumulator. The
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* buffer shift at the end of the function should be replaced by a
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* modulo operation, which is available on some DSPs.
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*
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* Last step: Copy the upper part of the spectral data to the overlap buffer.
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*
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* The qmf coefficient table is symmetric. The symmetry is exploited by
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* shrinking the coefficient table to half the size. The addressing mode
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* takes care of the symmetries. If the #define #QMFTABLE_FULL is set,
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* coefficient addressing works on the full table size. The code will be
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* slightly faster and slightly more compact.
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*
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* Workbuffer requirement: 2 x sizeof(**QmfBufferReal) * synQmf->no_channels
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* The workbuffer must be aligned
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*/
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void qmfSynthesisFiltering(
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HANDLE_QMF_FILTER_BANK synQmf, /*!< Handle of Qmf Synthesis Bank */
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FIXP_DBL **QmfBufferReal, /*!< Low and High band, real */
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FIXP_DBL **QmfBufferImag, /*!< Low and High band, imag */
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const QMF_SCALE_FACTOR *scaleFactor,
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const INT ov_len, /*!< split Slot of overlap and actual slots */
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INT_PCM_QMFOUT *timeOut, /*!< Pointer to output */
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const INT stride, /*!< stride factor of output */
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FIXP_DBL *pWorkBuffer /*!< pointer to temporal working buffer */
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) {
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int i;
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int L = synQmf->no_channels;
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int scaleFactorHighBand;
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int scaleFactorLowBand_ov, scaleFactorLowBand_no_ov;
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FDK_ASSERT(synQmf->no_channels >= synQmf->lsb);
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FDK_ASSERT(synQmf->no_channels >= synQmf->usb);
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/* adapt scaling */
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scaleFactorHighBand = -ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK -
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scaleFactor->hb_scale - synQmf->filterScale;
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scaleFactorLowBand_ov = -ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK -
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scaleFactor->ov_lb_scale - synQmf->filterScale;
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scaleFactorLowBand_no_ov = -ALGORITHMIC_SCALING_IN_ANALYSIS_FILTERBANK -
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scaleFactor->lb_scale - synQmf->filterScale;
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for (i = 0; i < synQmf->no_col; i++) /* ----- no_col loop ----- */
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{
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const FIXP_DBL *QmfBufferImagSlot = NULL;
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int scaleFactorLowBand =
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(i < ov_len) ? scaleFactorLowBand_ov : scaleFactorLowBand_no_ov;
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if (!(synQmf->flags & QMF_FLAG_LP)) QmfBufferImagSlot = QmfBufferImag[i];
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qmfSynthesisFilteringSlot(synQmf, QmfBufferReal[i], QmfBufferImagSlot,
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scaleFactorLowBand, scaleFactorHighBand,
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timeOut + (i * L * stride), stride, pWorkBuffer);
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} /* no_col loop i */
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}
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#endif /* QMF_PCM_H */
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