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Diffstat (limited to 'contrib/ffmpeg/libavutil/crc.c')
| -rw-r--r-- | contrib/ffmpeg/libavutil/crc.c | 151 |
1 files changed, 0 insertions, 151 deletions
diff --git a/contrib/ffmpeg/libavutil/crc.c b/contrib/ffmpeg/libavutil/crc.c deleted file mode 100644 index 743a64038..000000000 --- a/contrib/ffmpeg/libavutil/crc.c +++ /dev/null @@ -1,151 +0,0 @@ -/* - * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -#include "common.h" -#include "crc.h" - -#ifdef CONFIG_HARDCODED_TABLES -#include "crc_data.h" -#else -static struct { - uint8_t le; - uint8_t bits; - uint32_t poly; -} av_crc_table_params[AV_CRC_MAX] = { - [AV_CRC_8_ATM] = { 0, 8, 0x07 }, - [AV_CRC_16_ANSI] = { 0, 16, 0x8005 }, - [AV_CRC_16_CCITT] = { 0, 16, 0x1021 }, - [AV_CRC_32_IEEE] = { 0, 32, 0x04C11DB7 }, - [AV_CRC_32_IEEE_LE] = { 1, 32, 0xEDB88320 }, -}; -static AVCRC av_crc_table[AV_CRC_MAX][257]; -#endif - -/** - * Inits a crc table. - * @param ctx must be an array of sizeof(AVCRC)*257 or sizeof(AVCRC)*1024 - * @param cts_size size of ctx in bytes - * @param le if 1, lowest bit represents coefficient for highest exponent - * of corresponding polynomial (both for poly and actual CRC). - * If 0, you must swap the crc parameter and the result of av_crc - * if you need the standard representation (can be simplified in - * most cases to e.g. bswap16): - * bswap_32(crc << (32-bits)) - * @param bits number of bits for the CRC - * @param poly generator polynomial without the x**bits coefficient, in the - * representation as specified by le - * @return <0 on failure - */ -int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size){ - int i, j; - uint32_t c; - - if (bits < 8 || bits > 32 || poly >= (1LL<<bits)) - return -1; - if (ctx_size != sizeof(AVCRC)*257 && ctx_size != sizeof(AVCRC)*1024) - return -1; - - for (i = 0; i < 256; i++) { - if (le) { - for (c = i, j = 0; j < 8; j++) - c = (c>>1)^(poly & (-(c&1))); - ctx[i] = c; - } else { - for (c = i << 24, j = 0; j < 8; j++) - c = (c<<1) ^ ((poly<<(32-bits)) & (((int32_t)c)>>31) ); - ctx[i] = bswap_32(c); - } - } - ctx[256]=1; -#ifndef CONFIG_SMALL - if(ctx_size >= sizeof(AVCRC)*1024) - for (i = 0; i < 256; i++) - for(j=0; j<3; j++) - ctx[256*(j+1) + i]= (ctx[256*j + i]>>8) ^ ctx[ ctx[256*j + i]&0xFF ]; -#endif - - return 0; -} - -/** - * Get an initialized standard CRC table. - * @param crc_id ID of a standard CRC - * @return a pointer to the CRC table or NULL on failure - */ -const AVCRC *av_crc_get_table(AVCRCId crc_id){ -#ifndef CONFIG_HARDCODED_TABLES - if (!av_crc_table[crc_id][sizeof(av_crc_table[crc_id])/sizeof(av_crc_table[crc_id][0])-1]) - if (av_crc_init(av_crc_table[crc_id], - av_crc_table_params[crc_id].le, - av_crc_table_params[crc_id].bits, - av_crc_table_params[crc_id].poly, - sizeof(av_crc_table[crc_id])) < 0) - return NULL; -#endif - return av_crc_table[crc_id]; -} - -/** - * Calculate the CRC of a block - * @param crc CRC of previous blocks if any or initial value for CRC. - * @return CRC updated with the data from the given block - * - * @see av_crc_init() "le" parameter - */ -uint32_t av_crc(const AVCRC *ctx, uint32_t crc, const uint8_t *buffer, size_t length){ - const uint8_t *end= buffer+length; - -#ifndef CONFIG_SMALL - if(!ctx[256]) - while(buffer<end-3){ - crc ^= le2me_32(*(const uint32_t*)buffer); buffer+=4; - crc = ctx[3*256 + ( crc &0xFF)] - ^ctx[2*256 + ((crc>>8 )&0xFF)] - ^ctx[1*256 + ((crc>>16)&0xFF)] - ^ctx[0*256 + ((crc>>24) )]; - } -#endif - while(buffer<end) - crc = ctx[((uint8_t)crc) ^ *buffer++] ^ (crc >> 8); - - return crc; -} - -#ifdef TEST -#undef printf -int main(void){ - uint8_t buf[1999]; - int i; - int p[4][3]={{AV_CRC_32_IEEE_LE, 0xEDB88320, 0x3D5CDD04}, - {AV_CRC_32_IEEE , 0x04C11DB7, 0xC0F5BAE0}, - {AV_CRC_16_ANSI , 0x8005, 0x1FBB }, - {AV_CRC_8_ATM , 0x07, 0xE3 },}; - const AVCRC *ctx; - - for(i=0; i<sizeof(buf); i++) - buf[i]= i+i*i; - - for(i=0; i<4; i++){ - ctx = av_crc_get_table(p[i][0]); - printf("crc %08X =%X\n", p[i][1], av_crc(ctx, 0, buf, sizeof(buf))); - } - return 0; -} -#endif |