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Diffstat (limited to 'libSBRenc/src/env_bit.cpp')
| -rw-r--r-- | libSBRenc/src/env_bit.cpp | 192 |
1 files changed, 192 insertions, 0 deletions
diff --git a/libSBRenc/src/env_bit.cpp b/libSBRenc/src/env_bit.cpp new file mode 100644 index 0000000..1f8c48f --- /dev/null +++ b/libSBRenc/src/env_bit.cpp @@ -0,0 +1,192 @@ +/**************************************************************************** + + (C) copyright Fraunhofer-IIS (2004) + All Rights Reserved + + Please be advised that this software and/or program delivery is + Confidential Information of Fraunhofer and subject to and covered by the + + Fraunhofer IIS Software Evaluation Agreement + between Google Inc. and Fraunhofer + effective and in full force since March 1, 2012. + + You may use this software and/or program only under the terms and + conditions described in the above mentioned Fraunhofer IIS Software + Evaluation Agreement. Any other and/or further use requires a separate agreement. + + + This software and/or program is protected by copyright law and international + treaties. Any reproduction or distribution of this software and/or program, + or any portion of it, may result in severe civil and criminal penalties, and + will be prosecuted to the maximum extent possible under law. + + $Id$ + +*******************************************************************************/ +/*! + \file + \brief Remaining SBR Bit Writing Routines +*/ + +#include "env_bit.h" +#include "cmondata.h" + + +#ifndef min +#define min(a,b) ( a < b ? a:b) +#endif + +#ifndef max +#define max(a,b) ( a > b ? a:b) +#endif + +/* ***************************** crcAdvance **********************************/ +/** + * @fn + * @brief updates crc data register + * @return none + * + * This function updates the crc register + * + */ +static void crcAdvance(USHORT crcPoly, + USHORT crcMask, + USHORT *crc, + ULONG bValue, + INT bBits + ) +{ + INT i; + USHORT flag; + + for (i=bBits-1; i>=0; i--) { + flag = ((*crc) & crcMask) ? (1) : (0) ; + flag ^= (bValue & (1<<i)) ? (1) : (0) ; + + (*crc)<<=1; + if(flag) (*crc) ^= crcPoly; + } +} + + +/* ***************************** FDKsbrEnc_InitSbrBitstream **********************************/ +/** + * @fn + * @brief Inittialisation of sbr bitstream, write of dummy header and CRC + * @return none + * + * + * + */ + +INT FDKsbrEnc_InitSbrBitstream(HANDLE_COMMON_DATA hCmonData, + UCHAR *memoryBase, /*!< Pointer to bitstream buffer */ + INT memorySize, /*!< Length of bitstream buffer in bytes */ + HANDLE_FDK_CRCINFO hCrcInfo, + UINT sbrSyntaxFlags) /*!< SBR syntax flags */ +{ + INT crcRegion = 0; + + /* reset bit buffer */ + FDKresetBitbuffer(&hCmonData->sbrBitbuf, BS_WRITER); + + FDKinitBitStream(&hCmonData->tmpWriteBitbuf, memoryBase, + memorySize, 0, BS_WRITER); + + if (sbrSyntaxFlags & SBR_SYNTAX_CRC) { + if (sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC) + { /* Init and start CRC region */ + FDKwriteBits (&hCmonData->sbrBitbuf, 0x0, SI_SBR_DRM_CRC_BITS); + FDKcrcInit( hCrcInfo, 0x001d, 0xFFFF, SI_SBR_DRM_CRC_BITS ); + crcRegion = FDKcrcStartReg( hCrcInfo, &hCmonData->sbrBitbuf, 0 ); + } else { + FDKwriteBits (&hCmonData->sbrBitbuf, 0x0, SI_SBR_CRC_BITS); + } + } + + return (crcRegion); +} + + +/* ************************** FDKsbrEnc_AssembleSbrBitstream *******************************/ +/** + * @fn + * @brief Formats the SBR payload + * @return nothing + * + * Also the CRC will be calculated here. + * + */ + +void +FDKsbrEnc_AssembleSbrBitstream( HANDLE_COMMON_DATA hCmonData, + HANDLE_FDK_CRCINFO hCrcInfo, + INT crcRegion, + UINT sbrSyntaxFlags) +{ + USHORT crcReg = SBR_CRCINIT; + INT numCrcBits,i; + + /* check if SBR is present */ + if ( hCmonData==NULL ) + return; + + hCmonData->sbrFillBits = 0; /* Fill bits are written only for GA streams */ + + if ( sbrSyntaxFlags & SBR_SYNTAX_DRM_CRC ) + { + /* + * Calculate and write DRM CRC + */ + FDKcrcEndReg( hCrcInfo, &hCmonData->sbrBitbuf, crcRegion ); + FDKwriteBits( &hCmonData->tmpWriteBitbuf, FDKcrcGetCRC(hCrcInfo)^0xFF, SI_SBR_DRM_CRC_BITS ); + } + else + { + if ( !(sbrSyntaxFlags & SBR_SYNTAX_LOW_DELAY) ) + { + /* Do alignment here, because its defined as part of the sbr_extension_data */ + int sbrLoad = hCmonData->sbrHdrBits + hCmonData->sbrDataBits; + + if ( sbrSyntaxFlags & SBR_SYNTAX_CRC ) { + sbrLoad += SI_SBR_CRC_BITS; + } + + sbrLoad += 4; /* Do byte Align with 4 bit offset. ISO/IEC 14496-3:2005(E) page 39. */ + + hCmonData->sbrFillBits = (8 - (sbrLoad % 8)) % 8; + + /* + append fill bits + */ + FDKwriteBits(&hCmonData->sbrBitbuf, 0, hCmonData->sbrFillBits ); + + FDK_ASSERT(FDKgetValidBits(&hCmonData->sbrBitbuf) % 8 == 4); + } + + /* + calculate crc + */ + if ( sbrSyntaxFlags & SBR_SYNTAX_CRC ) { + FDK_BITSTREAM tmpCRCBuf = hCmonData->sbrBitbuf; + FDKresetBitbuffer( &tmpCRCBuf, BS_READER ); + + numCrcBits = hCmonData->sbrHdrBits + hCmonData->sbrDataBits + hCmonData->sbrFillBits; + + for(i=0;i<numCrcBits;i++){ + INT bit; + bit = FDKreadBits(&tmpCRCBuf,1); + crcAdvance(SBR_CRC_POLY,SBR_CRC_MASK,&crcReg,bit,1); + } + crcReg &= (SBR_CRC_RANGE); + + /* + * Write CRC data. + */ + FDKwriteBits (&hCmonData->tmpWriteBitbuf, crcReg, SI_SBR_CRC_BITS); + } + } + + FDKsyncCache(&hCmonData->tmpWriteBitbuf); +} + |