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Diffstat (limited to 'fdk-aac/libAACdec/src/aacdec_hcr_bit.cpp')
-rw-r--r-- | fdk-aac/libAACdec/src/aacdec_hcr_bit.cpp | 164 |
1 files changed, 164 insertions, 0 deletions
diff --git a/fdk-aac/libAACdec/src/aacdec_hcr_bit.cpp b/fdk-aac/libAACdec/src/aacdec_hcr_bit.cpp new file mode 100644 index 0000000..0198659 --- /dev/null +++ b/fdk-aac/libAACdec/src/aacdec_hcr_bit.cpp @@ -0,0 +1,164 @@ +/* ----------------------------------------------------------------------------- +Software License for The Fraunhofer FDK AAC Codec Library for Android + +© 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. + +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 +----------------------------------------------------------------------------- */ + +/**************************** AAC decoder library ****************************** + + Author(s): Robert Weidner (DSP Solutions) + + Description: HCR Decoder: Bitstream reading + +*******************************************************************************/ + +#include "aacdec_hcr_bit.h" + +/*--------------------------------------------------------------------------------------------- + description: This function toggles the read direction. +----------------------------------------------------------------------------------------------- + input: current read direction +----------------------------------------------------------------------------------------------- + return: new read direction +-------------------------------------------------------------------------------------------- +*/ +UCHAR ToggleReadDirection(UCHAR readDirection) { + if (readDirection == FROM_LEFT_TO_RIGHT) { + return FROM_RIGHT_TO_LEFT; + } else { + return FROM_LEFT_TO_RIGHT; + } +} + +/*--------------------------------------------------------------------------------------------- + description: This function returns a bit from the bitstream according to +read direction. It is called very often, therefore it makes sense to inline it +(runtime). +----------------------------------------------------------------------------------------------- + input: - handle to FDK bitstream + - reference value marking start of bitfield + - pLeftStartOfSegment + - pRightStartOfSegment + - readDirection +----------------------------------------------------------------------------------------------- + return: - bit from bitstream +-------------------------------------------------------------------------------------------- +*/ +UINT HcrGetABitFromBitstream(HANDLE_FDK_BITSTREAM bs, const INT bsAnchor, + INT *pLeftStartOfSegment, + INT *pRightStartOfSegment, UCHAR readDirection) { + UINT bit; + INT readBitOffset; + + if (readDirection == FROM_LEFT_TO_RIGHT) { + readBitOffset = (INT)FDKgetValidBits(bs) - bsAnchor + *pLeftStartOfSegment; + if (readBitOffset) { + FDKpushBiDirectional(bs, readBitOffset); + } + + bit = FDKreadBits(bs, 1); + + *pLeftStartOfSegment += 1; + } else { + readBitOffset = (INT)FDKgetValidBits(bs) - bsAnchor + *pRightStartOfSegment; + if (readBitOffset) { + FDKpushBiDirectional(bs, readBitOffset); + } + + /* to be replaced with a brother function of FDKreadBits() */ + bit = FDKreadBits(bs, 1); + FDKpushBack(bs, 2); + + *pRightStartOfSegment -= 1; + } + + return (bit); +} |