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- /*
- * CRC functions for mpeg PSI tables
- * Copyright (C) 2010-2011 Unix Solutions Ltd.
- *
- * Released under MIT license.
- * See LICENSE-MIT.txt for license terms.
- */
- #include <netdb.h>
-
- #include "tsfuncs.h"
-
- #define CRC32_POLY 0x04C11DB7L
-
- static int crc_table_initialized = 0;
- static uint32_t crc32_table[256];
-
- void ts_crc32_init(void) {
- int i, j;
- uint32_t crc;
- if (crc_table_initialized)
- return;
- crc_table_initialized = 1;
- for (i=0; i<256; i++) {
- crc = i << 24;
- for (j=0; j<8; j++) {
- if (crc & 0x80000000L)
- crc = (crc << 1) ^ CRC32_POLY;
- else
- crc = (crc << 1);
- }
- crc32_table[i] = crc;
- }
- crc_table_initialized = 1;
- }
-
- uint32_t ts_crc32(uint8_t *data, int data_size) {
- int i, j;
- uint32_t crc = 0xffffffff;
- if (!crc_table_initialized) {
- ts_crc32_init();
- }
- for (j=0; j<data_size; j++) {
- i = ((crc >> 24) ^ *data++) & 0xff;
- crc = (crc << 8) ^ crc32_table[i];
- }
- return crc;
- }
-
- uint32_t ts_crc32_section(struct ts_section_header *section_header) {
- return ts_crc32(section_header->section_data, section_header->section_data_len);
- }
-
- int ts_crc32_section_check(struct ts_section_header *section_header, char *table) {
- uint32_t check_crc = ts_crc32(section_header->section_data, section_header->section_data_len);
-
- if (check_crc != 0) {
- ts_LOGf("!!! Wrong %s table CRC! It should be 0 but it is 0x%08x (CRC in data is 0x%08x)\n",
- table,
- check_crc,
- section_header->CRC);
- return 0;
- }
- return 1;
- }
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