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/*
File: file_mpg.c
Copyright (C) 1998-2005,2007 Christophe GRENIER <grenier@cgsecurity.org>
This software is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
This program 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 General Public License for more details.
You should have received a copy of the GNU General Public License along
with this program; if not, write the Free Software Foundation, Inc., 51
Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "filegen.h"
static void register_header_check_mpg(file_stat_t *file_stat);
static int header_check_mpg(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new);
const file_hint_t file_hint_mpg= {
.extension="mpg",
.description="Moving Picture Experts Group video",
.min_header_distance=0,
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_mpg
};
static const unsigned char mpg_header[3]= {0x00, 0x00, 0x01};
static void register_header_check_mpg(file_stat_t *file_stat)
{
register_header_check(0, mpg_header,sizeof(mpg_header), &header_check_mpg, file_stat);
}
static int header_check_mpg(const unsigned char *buffer, const unsigned int buffer_size, const unsigned int safe_header_only, const file_recovery_t *file_recovery, file_recovery_t *file_recovery_new)
{
if(file_recovery!=NULL && file_recovery->file_stat!=NULL && file_recovery->file_stat->file_hint==&file_hint_mpg)
return 0;
/* ISO/IEC 11172/13818-1 SYSTEM MULTIPLEXED PACKETIZED ELEMENTARY *
* STREAM AND HEADERS *
* 0x000001BA pack header start code *
* 0x000001BB system header start code *
* 2 bytes: header_size
* 1 byte: stream_id
* 0x000001BE padding block start code *
* 0x000001BD private 1 block start code *
* 0x000001BF private 2 block start code *
* *
* ISO/IEC 11172-2/13818-2 (MPEG-1/2 video) ELEMENTARY VIDEO HEADER *
* 0x000001B3 video sequence start code *
* 0x000001B2 video user meta data start code *
* *
* ISO/IEC 14496-2 (MPEG-4 video) ELEMENTARY VIDEO HEADER *
* 0x000001B0 visual object sequence start code *
* 0x000001B2 user meta data start code *
* 0x000001B5 visual object start code */
if(buffer[0]==0x00 && buffer[1]==0x00 && buffer[2]==0x01 &&
(buffer[3]==0xB0 ||
(buffer[3]==0xB3 && ((buffer[4]<<8)+(buffer[5]>>8)>0) && ((buffer[5]<<8)+buffer[6]>0)) ||
buffer[3]==0xB5 ||
buffer[3]==0xBA ||
(buffer[3]==0xBB && (buffer[4]<<8)+(buffer[5]>>8)>0 && (buffer[6]&0x80)==0x80)))
{
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_mpg.extension;
return 1;
}
return 0;
}
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