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Diffstat (limited to 'libFDK/src/FDK_crc.cpp')
| -rw-r--r-- | libFDK/src/FDK_crc.cpp | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/libFDK/src/FDK_crc.cpp b/libFDK/src/FDK_crc.cpp new file mode 100644 index 0000000..0049807 --- /dev/null +++ b/libFDK/src/FDK_crc.cpp @@ -0,0 +1,397 @@ +/******************************** 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;i<MAX_CRC_REGS;i++) { + hCrcInfo->crcRegData[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<nBytes; i++) { + crc = (crc<<8)^pCrcLookup[((crc>>8)^((UCHAR)FDKreadBits(hBs,8)))&0xFF]; + } + } + else { + for (i=0; i<nBytes; i++) { + crc = (crc<<8)^pCrcLookup[((crc>>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)<rBits) ) { + bits = rD->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; +} + |