/******************************** MPEG Audio Encoder ************************** (C) Copyright Fraunhofer IIS (1999) 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. $Id$ Initial author: contents/description: CRC calculation ******************************************************************************/ #include "FDK_crc.h" /*---------------- constants -----------------------*/ /** * \brief This table defines precalculated lookup tables for crc polynom x^16 + x^15 + x^2 + x^0. */ static const USHORT crcLookup_16_15_2_0[256] = { 0x0000, 0x8005, 0x800f, 0x000a, 0x801b, 0x001e, 0x0014, 0x8011, 0x8033, 0x0036, 0x003c, 0x8039, 0x0028, 0x802d, 0x8027, 0x0022, 0x8063, 0x0066, 0x006c, 0x8069, 0x0078, 0x807d, 0x8077, 0x0072, 0x0050, 0x8055, 0x805f, 0x005a, 0x804b, 0x004e, 0x0044, 0x8041, 0x80c3, 0x00c6, 0x00cc, 0x80c9, 0x00d8, 0x80dd, 0x80d7, 0x00d2, 0x00f0, 0x80f5, 0x80ff, 0x00fa, 0x80eb, 0x00ee, 0x00e4, 0x80e1, 0x00a0, 0x80a5, 0x80af, 0x00aa, 0x80bb, 0x00be, 0x00b4, 0x80b1, 0x8093, 0x0096, 0x009c, 0x8099, 0x0088, 0x808d, 0x8087, 0x0082, 0x8183, 0x0186, 0x018c, 0x8189, 0x0198, 0x819d, 0x8197, 0x0192, 0x01b0, 0x81b5, 0x81bf, 0x01ba, 0x81ab, 0x01ae, 0x01a4, 0x81a1, 0x01e0, 0x81e5, 0x81ef, 0x01ea, 0x81fb, 0x01fe, 0x01f4, 0x81f1, 0x81d3, 0x01d6, 0x01dc, 0x81d9, 0x01c8, 0x81cd, 0x81c7, 0x01c2, 0x0140, 0x8145, 0x814f, 0x014a, 0x815b, 0x015e, 0x0154, 0x8151, 0x8173, 0x0176, 0x017c, 0x8179, 0x0168, 0x816d, 0x8167, 0x0162, 0x8123, 0x0126, 0x012c, 0x8129, 0x0138, 0x813d, 0x8137, 0x0132, 0x0110, 0x8115, 0x811f, 0x011a, 0x810b, 0x010e, 0x0104, 0x8101, 0x8303, 0x0306, 0x030c, 0x8309, 0x0318, 0x831d, 0x8317, 0x0312, 0x0330, 0x8335, 0x833f, 0x033a, 0x832b, 0x032e, 0x0324, 0x8321, 0x0360, 0x8365, 0x836f, 0x036a, 0x837b, 0x037e, 0x0374, 0x8371, 0x8353, 0x0356, 0x035c, 0x8359, 0x0348, 0x834d, 0x8347, 0x0342, 0x03c0, 0x83c5, 0x83cf, 0x03ca, 0x83db, 0x03de, 0x03d4, 0x83d1, 0x83f3, 0x03f6, 0x03fc, 0x83f9, 0x03e8, 0x83ed, 0x83e7, 0x03e2, 0x83a3, 0x03a6, 0x03ac, 0x83a9, 0x03b8, 0x83bd, 0x83b7, 0x03b2, 0x0390, 0x8395, 0x839f, 0x039a, 0x838b, 0x038e, 0x0384, 0x8381, 0x0280, 0x8285, 0x828f, 0x028a, 0x829b, 0x029e, 0x0294, 0x8291, 0x82b3, 0x02b6, 0x02bc, 0x82b9, 0x02a8, 0x82ad, 0x82a7, 0x02a2, 0x82e3, 0x02e6, 0x02ec, 0x82e9, 0x02f8, 0x82fd, 0x82f7, 0x02f2, 0x02d0, 0x82d5, 0x82df, 0x02da, 0x82cb, 0x02ce, 0x02c4, 0x82c1, 0x8243, 0x0246, 0x024c, 0x8249, 0x0258, 0x825d, 0x8257, 0x0252, 0x0270, 0x8275, 0x827f, 0x027a, 0x826b, 0x026e, 0x0264, 0x8261, 0x0220, 0x8225, 0x822f, 0x022a, 0x823b, 0x023e, 0x0234, 0x8231, 0x8213, 0x0216, 0x021c, 0x8219, 0x0208, 0x820d, 0x8207, 0x0202 }; /** * \brief This table defines precalculated lookup tables for crc polynom x^16 + x^12 + x^5 + x^0. */ static const USHORT crcLookup_16_12_5_0[256] = { 0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50a5, 0x60c6, 0x70e7, 0x8108, 0x9129, 0xa14a, 0xb16b, 0xc18c, 0xd1ad, 0xe1ce, 0xf1ef, 0x1231, 0x0210, 0x3273, 0x2252, 0x52b5, 0x4294, 0x72f7, 0x62d6, 0x9339, 0x8318, 0xb37b, 0xa35a, 0xd3bd, 0xc39c, 0xf3ff, 0xe3de, 0x2462, 0x3443, 0x0420, 0x1401, 0x64e6, 0x74c7, 0x44a4, 0x5485, 0xa56a, 0xb54b, 0x8528, 0x9509, 0xe5ee, 0xf5cf, 0xc5ac, 0xd58d, 0x3653, 0x2672, 0x1611, 0x0630, 0x76d7, 0x66f6, 0x5695, 0x46b4, 0xb75b, 0xa77a, 0x9719, 0x8738, 0xf7df, 0xe7fe, 0xd79d, 0xc7bc, 0x48c4, 0x58e5, 0x6886, 0x78a7, 0x0840, 0x1861, 0x2802, 0x3823, 0xc9cc, 0xd9ed, 0xe98e, 0xf9af, 0x8948, 0x9969, 0xa90a, 0xb92b, 0x5af5, 0x4ad4, 0x7ab7, 0x6a96, 0x1a71, 0x0a50, 0x3a33, 0x2a12, 0xdbfd, 0xcbdc, 0xfbbf, 0xeb9e, 0x9b79, 0x8b58, 0xbb3b, 0xab1a, 0x6ca6, 0x7c87, 0x4ce4, 0x5cc5, 0x2c22, 0x3c03, 0x0c60, 0x1c41, 0xedae, 0xfd8f, 0xcdec, 0xddcd, 0xad2a, 0xbd0b, 0x8d68, 0x9d49, 0x7e97, 0x6eb6, 0x5ed5, 0x4ef4, 0x3e13, 0x2e32, 0x1e51, 0x0e70, 0xff9f, 0xefbe, 0xdfdd, 0xcffc, 0xbf1b, 0xaf3a, 0x9f59, 0x8f78, 0x9188, 0x81a9, 0xb1ca, 0xa1eb, 0xd10c, 0xc12d, 0xf14e, 0xe16f, 0x1080, 0x00a1, 0x30c2, 0x20e3, 0x5004, 0x4025, 0x7046, 0x6067, 0x83b9, 0x9398, 0xa3fb, 0xb3da, 0xc33d, 0xd31c, 0xe37f, 0xf35e, 0x02b1, 0x1290, 0x22f3, 0x32d2, 0x4235, 0x5214, 0x6277, 0x7256, 0xb5ea, 0xa5cb, 0x95a8, 0x8589, 0xf56e, 0xe54f, 0xd52c, 0xc50d, 0x34e2, 0x24c3, 0x14a0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405, 0xa7db, 0xb7fa, 0x8799, 0x97b8, 0xe75f, 0xf77e, 0xc71d, 0xd73c, 0x26d3, 0x36f2, 0x0691, 0x16b0, 0x6657, 0x7676, 0x4615, 0x5634, 0xd94c, 0xc96d, 0xf90e, 0xe92f, 0x99c8, 0x89e9, 0xb98a, 0xa9ab, 0x5844, 0x4865, 0x7806, 0x6827, 0x18c0, 0x08e1, 0x3882, 0x28a3, 0xcb7d, 0xdb5c, 0xeb3f, 0xfb1e, 0x8bf9, 0x9bd8, 0xabbb, 0xbb9a, 0x4a75, 0x5a54, 0x6a37, 0x7a16, 0x0af1, 0x1ad0, 0x2ab3, 0x3a92, 0xfd2e, 0xed0f, 0xdd6c, 0xcd4d, 0xbdaa, 0xad8b, 0x9de8, 0x8dc9, 0x7c26, 0x6c07, 0x5c64, 0x4c45, 0x3ca2, 0x2c83, 0x1ce0, 0x0cc1, 0xef1f, 0xff3e, 0xcf5d, 0xdf7c, 0xaf9b, 0xbfba, 0x8fd9, 0x9ff8, 0x6e17, 0x7e36, 0x4e55, 0x5e74, 0x2e93, 0x3eb2, 0x0ed1, 0x1ef0 }; /*--------------- function declarations --------------------*/ static inline INT calcCrc_Bits( USHORT * const pCrc, USHORT crcMask, USHORT crcPoly, HANDLE_FDK_BITSTREAM hBs, INT nBits ); static inline INT calcCrc_Bytes( USHORT * const pCrc, const USHORT * pCrcLookup, HANDLE_FDK_BITSTREAM hBs, INT nBytes ); static void crcCalc( HANDLE_FDK_CRCINFO hCrcInfo, HANDLE_FDK_BITSTREAM hBs, const INT reg ); /*------------- function definitions ----------------*/ void FDKcrcInit( HANDLE_FDK_CRCINFO hCrcInfo, const UINT crcPoly, const UINT crcStartValue, const UINT crcLen ) { /* crc polynom example: x^16 + x^15 + x^2 + x^0 (1) 1000 0000 0000 0101 -> 0x8005 x^16 + x^12 + x^5 + x^0 (1) 0001 0000 0010 0001 -> 0x1021 x^8 + x^4 + x^3 + x^2 + x^0 (1) 0001 1101 -> 0x001d */ hCrcInfo->crcLen = crcLen; hCrcInfo->crcPoly = crcPoly; hCrcInfo->startValue = crcStartValue; hCrcInfo->crcMask = (crcLen) ? (1<<(crcLen-1)) : 0; FDKcrcReset(hCrcInfo); hCrcInfo->pCrcLookup = 0; if (hCrcInfo->crcLen==16) { switch ( crcPoly ) { case 0x8005: hCrcInfo->pCrcLookup = crcLookup_16_15_2_0; break; case 0x1021: hCrcInfo->pCrcLookup = crcLookup_16_12_5_0; break; case 0x001d: default: /* no lookup table */ hCrcInfo->pCrcLookup = 0; } } } void FDKcrcReset(HANDLE_FDK_CRCINFO hCrcInfo) { int i; hCrcInfo->crcValue = hCrcInfo->startValue; for(i=0;icrcRegData[i].isActive = 0; } hCrcInfo->regStart = 0; hCrcInfo->regStop = 0; } INT FDKcrcStartReg( HANDLE_FDK_CRCINFO hCrcInfo, const HANDLE_FDK_BITSTREAM hBs, const INT mBits ) { int reg = hCrcInfo->regStart; FDK_ASSERT(hCrcInfo->crcRegData[reg].isActive==0); hCrcInfo->crcRegData[reg].isActive = 1; hCrcInfo->crcRegData[reg].maxBits = mBits; hCrcInfo->crcRegData[reg].validBits = FDKgetValidBits(hBs) ; hCrcInfo->crcRegData[reg].bitBufCntBits = 0; hCrcInfo->regStart = (hCrcInfo->regStart+1)%MAX_CRC_REGS; return (reg); } INT FDKcrcEndReg( HANDLE_FDK_CRCINFO hCrcInfo, const HANDLE_FDK_BITSTREAM hBs, const INT reg ) { FDK_ASSERT((reg==(INT)hCrcInfo->regStop)&&(hCrcInfo->crcRegData[reg].isActive==1)); if (hBs->ConfigCache==BS_WRITER) { hCrcInfo->crcRegData[reg].bitBufCntBits = FDKgetValidBits(hBs) - hCrcInfo->crcRegData[reg].validBits; } else { hCrcInfo->crcRegData[reg].bitBufCntBits = hCrcInfo->crcRegData[reg].validBits - FDKgetValidBits(hBs); } if (hCrcInfo->crcRegData[reg].maxBits == 0) { hCrcInfo->crcRegData[reg].maxBits = hCrcInfo->crcRegData[reg].bitBufCntBits; } crcCalc( hCrcInfo, hBs, reg); hCrcInfo->crcRegData[reg].isActive = 0; hCrcInfo->regStop = (hCrcInfo->regStop+1)%MAX_CRC_REGS; return 0; } USHORT FDKcrcGetCRC( const HANDLE_FDK_CRCINFO hCrcInfo ) { return ( hCrcInfo->crcValue & (((hCrcInfo->crcMask-1)<<1)+1) ); } /** * \brief Calculate crc bits. * * Calculate crc starting at current bitstream postion over nBits. * * \param pCrc Pointer to an outlying allocated crc info structure. * \param crcMask CrcMask in use. * \param crcPoly Crc polynom in use. * \param hBs Handle to current bit buffer structure. * \param nBits Number of processing bits. * * \return Number of processed bits. */ static inline INT calcCrc_Bits( USHORT * const pCrc, USHORT crcMask, USHORT crcPoly, HANDLE_FDK_BITSTREAM hBs, INT nBits ) { int i; USHORT crc = *pCrc; /* get crc value */ if (hBs!=NULL) { for (i = 0; (i < nBits); i++) { USHORT tmp = FDKreadBits(hBs,1); // process single bit tmp ^= ( (crc & crcMask) ? 1 : 0 ); tmp *= crcPoly; crc <<= 1; crc ^= tmp; } } else { for (i = 0; (i < nBits); i++) { USHORT tmp = 0; // process single bit tmp ^= ( (crc & crcMask) ? 1 : 0 ); tmp *= crcPoly; crc <<= 1; crc ^= tmp; } } *pCrc = crc; /* update crc value */ return nBits; } /** * \brief Calculate crc bytes. * * Calculate crc starting at current bitstream postion over nBytes. * * \param pCrc Pointer to an outlying allocated crc info structure. * \param pCrcLookup Pointer to lookup table used for fast crc calculation. * \param hBs Handle to current bit buffer structure. * \param nBits Number of processing bytes. * * \return Number of processed bits. */ static inline INT calcCrc_Bytes( USHORT * const pCrc, const USHORT * pCrcLookup, HANDLE_FDK_BITSTREAM hBs, INT nBytes ) { int i; USHORT crc = *pCrc; /* get crc value */ if (hBs!=NULL) { for (i=0; i>8)^((UCHAR)FDKreadBits(hBs,8)))&0xFF]; } } else { for (i=0; i>8)^((UCHAR)0))&0xFF]; } } *pCrc = crc; /* update crc value */ return (i); } /** * \brief Calculate crc. * * Calculate crc. Lenght depends on mBits parameter in FDKcrcStartReg() configuration. * * \param hCrcInfo Pointer to an outlying allocated crc info structure. * \param hBs Pointer to current bit buffer structure. * \param reg Crc region ID. * * \return Number of processed bits. */ static void crcCalc( HANDLE_FDK_CRCINFO hCrcInfo, HANDLE_FDK_BITSTREAM hBs, const INT reg ) { USHORT crc = hCrcInfo->crcValue; CCrcRegData *rD = &hCrcInfo->crcRegData[reg]; FDK_BITSTREAM bsReader; if (hBs->ConfigCache==BS_READER) { bsReader = *hBs; FDKpushBiDirectional(&bsReader, -(INT)(rD->validBits-FDKgetValidBits(&bsReader))); } else { FDKinitBitStream(&bsReader, hBs->hBitBuf.Buffer, hBs->hBitBuf.bufSize, hBs->hBitBuf.ValidBits, BS_READER); FDKpushBiDirectional(&bsReader, rD->validBits); } int bits, rBits; rBits = (rD->maxBits>=0) ? rD->maxBits : -rD->maxBits; /* ramaining bits */ if ((rD->maxBits>0) && (((INT)rD->bitBufCntBits>>3<<3)bitBufCntBits; } else { bits = rBits; } int words = bits >> 3; /* processing bytes */ int mBits = bits & 0x7; /* modulo bits */ if(hCrcInfo->pCrcLookup) { rBits -= (calcCrc_Bytes(&crc, hCrcInfo->pCrcLookup, &bsReader, words)<<3); } else { rBits -= calcCrc_Bits(&crc, hCrcInfo->crcMask, hCrcInfo->crcPoly, &bsReader, words<<3 ); } /* remaining valid bits*/ if(mBits!=0) { rBits -= calcCrc_Bits(&crc, hCrcInfo->crcMask, hCrcInfo->crcPoly, &bsReader, mBits ); } if (rBits!=0) { /* zero bytes */ if ( (hCrcInfo->pCrcLookup) && (rBits>8) ) { rBits -= (calcCrc_Bytes(&crc, hCrcInfo->pCrcLookup, NULL, rBits>>3)<<3); } /* remaining zero bits */ if (rBits!=0) { rBits -= calcCrc_Bits(&crc, hCrcInfo->crcMask, hCrcInfo->crcPoly, NULL, rBits ); } } hCrcInfo->crcValue = crc; }