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authorThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
committerThe Android Open Source Project <initial-contribution@android.com>2012-07-11 10:15:24 -0700
commit2228e360595641dd906bf1773307f43d304f5b2e (patch)
tree57f3d390ebb0782cc0de0fb984c8ea7e45b4f386 /libSBRdec/src/sbr_crc.cpp
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Snapshot 2bda038c163298531d47394bc2c09e1409c5d0db
Change-Id: If584e579464f28b97d50e51fc76ba654a5536c54
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+
+/* -----------------------------------------------------------------------------------------------------------
+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
+----------------------------------------------------------------------------------------------------------- */
+
+/*!
+ \file
+ \brief CRC check coutines
+*/
+
+#include "sbr_crc.h"
+
+#include "FDK_bitstream.h"
+#include "transcendent.h"
+
+#define MAXCRCSTEP 16
+#define MAXCRCSTEP_LD 4
+
+/*!
+ \brief crc calculation
+*/
+static ULONG
+calcCRC (HANDLE_CRC hCrcBuf, ULONG bValue, int nBits)
+{
+ int i;
+ ULONG bMask = (1UL << (nBits - 1));
+
+ for (i = 0; i < nBits; i++, bMask >>= 1) {
+ USHORT flag = (hCrcBuf->crcState & hCrcBuf->crcMask) ? 1 : 0;
+ USHORT flag1 = (bMask & bValue) ? 1 : 0;
+
+ flag ^= flag1;
+ hCrcBuf->crcState <<= 1;
+ if (flag)
+ hCrcBuf->crcState ^= hCrcBuf->crcPoly;
+ }
+
+ return (hCrcBuf->crcState);
+}
+
+
+/*!
+ \brief crc
+*/
+static int
+getCrc (HANDLE_FDK_BITSTREAM hBs, ULONG NrBits)
+{
+ int i;
+ CRC_BUFFER CrcBuf;
+
+ CrcBuf.crcState = SBR_CRC_START;
+ CrcBuf.crcPoly = SBR_CRC_POLY;
+ CrcBuf.crcMask = SBR_CRC_MASK;
+
+ int CrcStep = NrBits>>MAXCRCSTEP_LD;
+
+ int CrcNrBitsRest = (NrBits - CrcStep * MAXCRCSTEP);
+ ULONG bValue;
+
+ for (i = 0; i < CrcStep; i++) {
+ bValue = FDKreadBits (hBs, MAXCRCSTEP);
+ calcCRC (&CrcBuf, bValue, MAXCRCSTEP);
+ }
+
+ bValue = FDKreadBits (hBs, CrcNrBitsRest);
+ calcCRC (&CrcBuf, bValue, CrcNrBitsRest);
+
+ return (CrcBuf.crcState & SBR_CRC_RANGE);
+
+}
+
+
+/*!
+ \brief crc interface
+ \return 1: CRC OK, 0: CRC check failure
+*/
+int
+SbrCrcCheck (HANDLE_FDK_BITSTREAM hBs, /*!< handle to bit-buffer */
+ LONG NrBits) /*!< max. CRC length */
+{
+ int crcResult = 1;
+ ULONG NrCrcBits;
+ ULONG crcCheckResult;
+ LONG NrBitsAvailable;
+ ULONG crcCheckSum;
+
+ crcCheckSum = FDKreadBits (hBs, 10);
+
+ NrBitsAvailable = FDKgetValidBits(hBs);
+ if (NrBitsAvailable <= 0){
+ return 0;
+ }
+
+ NrCrcBits = fixMin ((INT)NrBits, (INT)NrBitsAvailable);
+
+ crcCheckResult = getCrc (hBs, NrCrcBits);
+ FDKpushBack(hBs, (NrBitsAvailable - FDKgetValidBits(hBs)) );
+
+
+ if (crcCheckResult != crcCheckSum) {
+ crcResult = 0;
+ }
+
+ return (crcResult);
+}