/* -----------------------------------------------------------------------------
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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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/******************* MPEG transport format decoder library *********************
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Author(s): Josef Hoepfl
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Description: ADTS interface
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*******************************************************************************/
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#include "tpdec_adts.h"
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#include "FDK_bitstream.h"
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void adtsRead_CrcInit(
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HANDLE_ADTS pAdts) /*!< pointer to adts crc info stucture */
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{
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FDKcrcInit(&pAdts->crcInfo, 0x8005, 0xFFFF, 16);
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}
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int adtsRead_CrcStartReg(
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HANDLE_ADTS pAdts, /*!< pointer to adts stucture */
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HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
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int mBits /*!< number of bits in crc region */
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) {
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if (pAdts->bs.protection_absent) {
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return 0;
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}
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return (FDKcrcStartReg(&pAdts->crcInfo, hBs, mBits));
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}
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void adtsRead_CrcEndReg(
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HANDLE_ADTS pAdts, /*!< pointer to adts crc info stucture */
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HANDLE_FDK_BITSTREAM hBs, /*!< handle to current bit buffer structure */
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int reg /*!< crc region */
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) {
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if (pAdts->bs.protection_absent == 0) {
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FDKcrcEndReg(&pAdts->crcInfo, hBs, reg);
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}
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}
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TRANSPORTDEC_ERROR adtsRead_CrcCheck(HANDLE_ADTS pAdts) {
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TRANSPORTDEC_ERROR ErrorStatus = TRANSPORTDEC_OK;
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USHORT crc;
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if (pAdts->bs.protection_absent) return TRANSPORTDEC_OK;
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crc = FDKcrcGetCRC(&pAdts->crcInfo);
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if (crc != pAdts->crcReadValue) {
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return (TRANSPORTDEC_CRC_ERROR);
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}
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return (ErrorStatus);
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}
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#define Adts_Length_SyncWord 12
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#define Adts_Length_Id 1
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#define Adts_Length_Layer 2
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#define Adts_Length_ProtectionAbsent 1
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#define Adts_Length_Profile 2
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#define Adts_Length_SamplingFrequencyIndex 4
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#define Adts_Length_PrivateBit 1
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#define Adts_Length_ChannelConfiguration 3
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#define Adts_Length_OriginalCopy 1
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#define Adts_Length_Home 1
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#define Adts_Length_CopyrightIdentificationBit 1
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#define Adts_Length_CopyrightIdentificationStart 1
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#define Adts_Length_FrameLength 13
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#define Adts_Length_BufferFullness 11
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#define Adts_Length_NumberOfRawDataBlocksInFrame 2
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#define Adts_Length_CrcCheck 16
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TRANSPORTDEC_ERROR adtsRead_DecodeHeader(HANDLE_ADTS pAdts,
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CSAudioSpecificConfig *pAsc,
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HANDLE_FDK_BITSTREAM hBs,
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const INT ignoreBufferFullness) {
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INT crcReg;
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INT valBits;
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INT cmp_buffer_fullness;
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int i, adtsHeaderLength;
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STRUCT_ADTS_BS bs;
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CProgramConfig oldPce;
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/* Store the old PCE temporarily. Maybe we'll need it later if we
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have channelConfig=0 and no PCE in this frame. */
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FDKmemcpy(&oldPce, &pAsc->m_progrConfigElement, sizeof(CProgramConfig));
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valBits = FDKgetValidBits(hBs) + ADTS_SYNCLENGTH;
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if (valBits < ADTS_HEADERLENGTH) {
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return TRANSPORTDEC_NOT_ENOUGH_BITS;
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}
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/* adts_fixed_header */
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bs.mpeg_id = FDKreadBits(hBs, Adts_Length_Id);
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bs.layer = FDKreadBits(hBs, Adts_Length_Layer);
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bs.protection_absent = FDKreadBits(hBs, Adts_Length_ProtectionAbsent);
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bs.profile = FDKreadBits(hBs, Adts_Length_Profile);
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bs.sample_freq_index = FDKreadBits(hBs, Adts_Length_SamplingFrequencyIndex);
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bs.private_bit = FDKreadBits(hBs, Adts_Length_PrivateBit);
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bs.channel_config = FDKreadBits(hBs, Adts_Length_ChannelConfiguration);
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bs.original = FDKreadBits(hBs, Adts_Length_OriginalCopy);
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bs.home = FDKreadBits(hBs, Adts_Length_Home);
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/* adts_variable_header */
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bs.copyright_id = FDKreadBits(hBs, Adts_Length_CopyrightIdentificationBit);
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bs.copyright_start =
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FDKreadBits(hBs, Adts_Length_CopyrightIdentificationStart);
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bs.frame_length = FDKreadBits(hBs, Adts_Length_FrameLength);
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bs.adts_fullness = FDKreadBits(hBs, Adts_Length_BufferFullness);
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bs.num_raw_blocks =
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FDKreadBits(hBs, Adts_Length_NumberOfRawDataBlocksInFrame);
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bs.num_pce_bits = 0;
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adtsHeaderLength = ADTS_HEADERLENGTH;
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if (valBits < bs.frame_length * 8) {
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goto bail;
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}
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if (!bs.protection_absent) {
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FDKcrcReset(&pAdts->crcInfo);
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FDKpushBack(hBs, 56); /* complete fixed and variable header! */
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crcReg = FDKcrcStartReg(&pAdts->crcInfo, hBs, 0);
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FDKpushFor(hBs, 56);
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}
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if (!bs.protection_absent && bs.num_raw_blocks > 0) {
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if ((INT)FDKgetValidBits(hBs) < bs.num_raw_blocks * 16) {
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goto bail;
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}
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for (i = 0; i < bs.num_raw_blocks; i++) {
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pAdts->rawDataBlockDist[i] = (USHORT)FDKreadBits(hBs, 16);
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adtsHeaderLength += 16;
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}
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/* Change raw data blocks to delta values */
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pAdts->rawDataBlockDist[bs.num_raw_blocks] =
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bs.frame_length - 7 - bs.num_raw_blocks * 2 - 2;
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for (i = bs.num_raw_blocks; i > 0; i--) {
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pAdts->rawDataBlockDist[i] -= pAdts->rawDataBlockDist[i - 1];
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}
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}
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/* adts_error_check */
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if (!bs.protection_absent) {
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USHORT crc_check;
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FDKcrcEndReg(&pAdts->crcInfo, hBs, crcReg);
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if ((INT)FDKgetValidBits(hBs) < Adts_Length_CrcCheck) {
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goto bail;
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}
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crc_check = FDKreadBits(hBs, Adts_Length_CrcCheck);
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adtsHeaderLength += Adts_Length_CrcCheck;
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pAdts->crcReadValue = crc_check;
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/* Check header CRC in case of multiple raw data blocks */
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if (bs.num_raw_blocks > 0) {
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if (pAdts->crcReadValue != FDKcrcGetCRC(&pAdts->crcInfo)) {
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return TRANSPORTDEC_CRC_ERROR;
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}
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/* Reset CRC for the upcoming raw_data_block() */
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FDKcrcReset(&pAdts->crcInfo);
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}
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}
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/* check if valid header */
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if ((bs.layer != 0) || // we only support MPEG ADTS
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(bs.sample_freq_index >= 13) // we only support 96kHz - 7350kHz
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) {
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FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
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return TRANSPORTDEC_UNSUPPORTED_FORMAT;
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}
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/* special treatment of id-bit */
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if ((bs.mpeg_id == 0) && (pAdts->decoderCanDoMpeg4 == 0)) {
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/* MPEG-2 decoder cannot play MPEG-4 bitstreams */
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FDKpushFor(hBs, bs.frame_length * 8); // try again one frame later
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return TRANSPORTDEC_UNSUPPORTED_FORMAT;
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}
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if (!ignoreBufferFullness) {
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cmp_buffer_fullness =
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bs.frame_length * 8 +
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bs.adts_fullness * 32 * getNumberOfEffectiveChannels(bs.channel_config);
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/* Evaluate buffer fullness */
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if (bs.adts_fullness != 0x7FF) {
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if (pAdts->BufferFullnesStartFlag) {
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if (valBits < cmp_buffer_fullness) {
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/* Condition for start of decoding is not fulfilled */
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/* The current frame will not be decoded */
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FDKpushBack(hBs, adtsHeaderLength);
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if ((cmp_buffer_fullness + adtsHeaderLength) >
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(((8192 * 4) << 3) - 7)) {
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return TRANSPORTDEC_SYNC_ERROR;
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} else {
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return TRANSPORTDEC_NOT_ENOUGH_BITS;
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}
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} else {
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pAdts->BufferFullnesStartFlag = 0;
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}
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}
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}
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}
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/* Get info from ADTS header */
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AudioSpecificConfig_Init(pAsc);
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pAsc->m_aot = (AUDIO_OBJECT_TYPE)(bs.profile + 1);
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pAsc->m_samplingFrequencyIndex = bs.sample_freq_index;
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pAsc->m_samplingFrequency = SamplingRateTable[bs.sample_freq_index];
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pAsc->m_channelConfiguration = bs.channel_config;
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pAsc->m_samplesPerFrame = 1024;
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if (bs.channel_config == 0) {
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int pceBits = 0;
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UINT alignAnchor = FDKgetValidBits(hBs);
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if (FDKreadBits(hBs, 3) == ID_PCE) {
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/* Got luck! Parse the PCE */
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crcReg = adtsRead_CrcStartReg(pAdts, hBs, 0);
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CProgramConfig_Read(&pAsc->m_progrConfigElement, hBs, alignAnchor);
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adtsRead_CrcEndReg(pAdts, hBs, crcReg);
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pceBits = alignAnchor - FDKgetValidBits(hBs);
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/* store the number of PCE bits */
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bs.num_pce_bits = pceBits;
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} else {
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/* No PCE in this frame! Push back the ID tag bits. */
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FDKpushBack(hBs, 3);
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/* Encoders do not have to write a PCE in each frame.
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So if we already have a valid PCE we have to use it. */
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if (oldPce.isValid &&
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(bs.sample_freq_index ==
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pAdts->bs.sample_freq_index) /* we could compare the complete fixed
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header (bytes) here! */
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&& (bs.channel_config == pAdts->bs.channel_config) /* == 0 */
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&&
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(bs.mpeg_id ==
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pAdts->bs.mpeg_id)) { /* Restore previous PCE which is still valid */
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FDKmemcpy(&pAsc->m_progrConfigElement, &oldPce, sizeof(CProgramConfig));
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} else if (bs.mpeg_id == 0) {
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/* If not it seems that we have a implicit channel configuration.
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This mode is not allowed in the context of ISO/IEC 14496-3.
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Skip this frame and try the next one. */
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FDKpushFor(hBs, (bs.frame_length << 3) - adtsHeaderLength - 3);
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return TRANSPORTDEC_UNSUPPORTED_FORMAT;
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}
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/* else {
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ISO/IEC 13818-7 implicit channel mapping is allowed.
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So just open the box of chocolates to see what we got.
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} */
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}
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}
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/* Copy bit stream data struct to persistent memory now, once we passed all
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* sanity checks above. */
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FDKmemcpy(&pAdts->bs, &bs, sizeof(STRUCT_ADTS_BS));
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return TRANSPORTDEC_OK;
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bail:
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FDKpushBack(hBs, adtsHeaderLength);
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return TRANSPORTDEC_NOT_ENOUGH_BITS;
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}
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int adtsRead_GetRawDataBlockLength(HANDLE_ADTS pAdts, INT blockNum) {
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int length;
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if (pAdts->bs.num_raw_blocks == 0) {
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length =
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(pAdts->bs.frame_length - 7)
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<< 3; /* aac_frame_length subtracted by the header size (7 bytes). */
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if (pAdts->bs.protection_absent == 0)
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length -= 16; /* substract 16 bit CRC */
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} else {
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if (pAdts->bs.protection_absent) {
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length = -1; /* raw data block length is unknown */
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} else {
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if (blockNum < 0 || blockNum > 3) {
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length = -1;
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} else {
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length = (pAdts->rawDataBlockDist[blockNum] << 3) - 16;
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}
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}
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}
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if (blockNum == 0 && length > 0) {
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length -= pAdts->bs.num_pce_bits;
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}
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return length;
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}
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