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/*
File: file_mpg.c
Copyright (C) 1998-2005,2007-2009 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.
*/
#if !defined(SINGLE_FORMAT) || defined(SINGLE_FORMAT_mpg)
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#include <stdio.h>
#include "types.h"
#include "common.h"
#include "filegen.h"
#include "log.h"
/*@
@ requires valid_register_header_check(file_stat);
@*/
static void register_header_check_mpg(file_stat_t *file_stat);
const file_hint_t file_hint_mpg= {
.extension="mpg",
.description="Moving Picture Experts Group video",
.max_filesize=PHOTOREC_MAX_FILE_SIZE,
.recover=1,
.enable_by_default=1,
.register_header_check=®ister_header_check_mpg
};
/*@
@ requires \valid_read(buffer + (0 .. 13));
@ terminates \true;
@ assigns \nothing;
@*/
static unsigned int calculate_packet_size(const unsigned char *buffer)
{
/* http://dvd.sourceforge.net/dvdinfo/mpeghdrs.html */
if(buffer[0]!=0 || buffer[1]!=0 || buffer[2]!=1)
return 0;
switch(buffer[3])
{
/* Pack header: */
case 0xBA:
if((buffer[4]&0xc4)==0x44 && (buffer[6]&4)==4 && (buffer[8]&4)==4 &&
(buffer[9]&1)==1 && (buffer[12]&3)==3)
return (buffer[13] & 0x7) + 14;
if((buffer[4]&0xF1)==0x21 && (buffer[6]&1)==1 && (buffer[8]&1)==1 &&
(buffer[9]&0x80)==0x80 && (buffer[11]&1)==1)
return 12;
return 0;
/* Sequence Header */
case 0xB3:
if((buffer[10]&0x20)==0x20)
{
if((buffer[11]&3)!=0)
return 12+64; /* quantiser matrix */
return 12;
}
return 0;
/* Extension */
case 0xB5:
/* Sequence_Extension */
if((buffer[4]&0xF0)==0x10 && (buffer[7]&1)==1)
return 10;
/* Sequence_Display_Extension without color description */
if((buffer[4]&0xF0)==0x20 && (buffer[4]&1)==0 && (buffer[6]&2)==2)
return 9;
/* Sequence_Display_Extension with color description */
if((buffer[4]&0xF0)==0x20 && (buffer[4]&1)==1 && (buffer[9]&2)==2)
return 12;
/* Picture_Coding_Extension */
if((buffer[4]&0xF0)==0x40)
{
if((buffer[8]&0x40)==0)
return 9;
else
return 11;
}
return 0;
case 0xB8: /* Group of Pictures */
if((buffer[5]&0x40)==0x40)
return 8;
return 0;
case 0xB9: /* EOC */
return 4;
case 0xBD: /* Private stream 1 (non MPEG audio, subpictures) */
case 0xC0 ... 0xDF: /* Mpeg Audio stream */
case 0xE0 ... 0xEF: /* Mpeg Video stream */
#if 0
{
uint32_t pts = 0;
// This is mpeg 2:
if((buffer[6] & 0xC0) == 0x80 &&
// PTS DTS flags
(buffer[7] >> 7)==1)
{
pts = ((buffer[13] | (buffer[12] << 8) ) >> 1) |
((buffer[11] | (buffer[10] << 8) ) >> 1) << 15;
// log_debug("MPG2 (%u - 0x%02X)PTS is 0x%08X\n", current->id,buffer[3], pts);
// This is mpeg 1. The PTS goes right after the header and must
// have the bits 0x21 set:
}
else if((buffer[6] & 0x21)==0x21)
{
pts = ((buffer[10] | (buffer[9] << 8) ) >> 1) | ((buffer[8] | (buffer[7] << 8) ) >> 1) << 15;
//log_debug("MPG1 (%u - 0x%02X)PTS is 0x%08X\n", current->id,buffer[3], pts);
};
}
#endif
return (buffer[4] << 8) + buffer[5] + 6;
case 0xBB: /* System header */
case 0xBE: /* Padding stream */
case 0xBF: /* Private Stream 2 */
return (buffer[4] << 8) + buffer[5] + 6;
case 0:
return 0;
default:
#ifdef DEBUG_MPG
log_info("I dont know how to handle 0x%02X\n", buffer[3]);
#endif
return 0;
}
}
/*@
@ requires file_recovery->data_check==&data_check_mpg;
@ requires valid_data_check_param(buffer, buffer_size, file_recovery);
@ terminates \true;
@ ensures valid_data_check_result(\result, file_recovery);
@ assigns file_recovery->calculated_file_size;
@*/
static data_check_t data_check_mpg(const unsigned char *buffer, const unsigned int buffer_size, file_recovery_t *file_recovery)
{
/*@ assert file_recovery->calculated_file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@ assert file_recovery->file_size <= PHOTOREC_MAX_FILE_SIZE; */
/*@
@ loop assigns file_recovery->calculated_file_size;
@ loop variant file_recovery->file_size + buffer_size/2 - (file_recovery->calculated_file_size + 14);
@*/
while(file_recovery->calculated_file_size + buffer_size/2 >= file_recovery->file_size &&
file_recovery->calculated_file_size + 14 < file_recovery->file_size + buffer_size/2)
{
const unsigned int i=file_recovery->calculated_file_size + buffer_size/2 - file_recovery->file_size;
/*@ assert i < buffer_size - 14; */
const unsigned int ret=calculate_packet_size(&buffer[i]);
#ifdef DEBUG_MPG
log_info("data_check_mpg %llu 0x%02x %u\n", (long long unsigned)file_recovery->calculated_file_size, buffer[i+3], ret);
#endif
if(ret==0)
return DC_STOP;
/*@ assert ret > 0; */
file_recovery->calculated_file_size+=ret;
}
return DC_CONTINUE;
}
/*@
@ requires \valid(file_recovery_new);
@ terminates \true;
@ ensures valid_file_recovery(file_recovery_new);
@ assigns *file_recovery_new;
@*/
static int header_mpg_found(file_recovery_t *file_recovery_new)
{
reset_file_recovery(file_recovery_new);
file_recovery_new->extension=file_hint_mpg.extension;
if(file_recovery_new->blocksize < 14)
return 1;
file_recovery_new->data_check=&data_check_mpg;
file_recovery_new->file_check=&file_check_size;
return 1;
}
/*@
@ requires buffer_size >= 13;
@ requires \valid_read(buffer+(0..buffer_size-1));
@ terminates \true;
@ assigns \nothing;
@*/
static int is_valid_packet_size(const unsigned char *buffer, const unsigned int buffer_size)
{
unsigned int i=0;
/*@
@ loop assigns i;
@ loop variant 512 - (i+14);
@*/
while(i+14 < td_min(buffer_size,512U))
{
/*@ assert i < buffer_size - 14; */
const unsigned int ret=calculate_packet_size(&buffer[i]);
if(ret==0)
return 0;
/*@ assert ret > 0; */
i+=ret;
}
return 1;
}
/*@
@ requires buffer_size >= 13;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@*/
static int header_check_mpg_Pack(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(is_valid_packet_size(buffer, buffer_size)==0)
return 0;
/* MPEG-1 http://andrewduncan.ws/MPEG/MPEG-1.ps */
/* pack start code 0x1BA + MPEG-1 + SCR=0 */
if((buffer[4]&0xF1)==0x21 && (buffer[6]&1)==1 && (buffer[8]&1)==1 &&
(buffer[9]&0x80)==0x80 && (buffer[11]&1)==1)
{
if(buffer[5]==0 && buffer[6]==1 && buffer[7]==0 && buffer[8]==1)
{
return header_mpg_found(file_recovery_new);
}
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_mpg)
{
header_ignored(file_recovery_new);
return 0;
}
return header_mpg_found(file_recovery_new);
}
/* MPEG-2 Program stream http://neuron2.net/library/mpeg2/iso13818-1.pdf */
/* MPEG2 system header start code, several per file */
if((buffer[4]&0xc4)==0x44 && (buffer[6]&4)==4 && (buffer[8]&4)==4 && (buffer[9]&1)==1 && (buffer[12]&3)==3)
{
/*
* '01' 2 01
system_clock_reference_base [32..30] 3 00 0
marker_bit 1 1
system_clock_reference_base [29..15] 15 00 buffer[4]=0x44
0000 0000 buffer[5]=0x00
0000 0
marker_bit 1 1
system_clock_reference_base [14..0] 15 00 buffer[6]=0x04
0000 0000 buffer[7]=0x00
0000
0
marker_bit 1 1
system_clock_reference_extension 9 uimsbf
marker_bit 1
=> 0100 0100
*/
if(buffer[4]==0x44 && buffer[5]==0 && buffer[6]==4 && buffer[7]==0 && (buffer[8]&0xfc)==4)
{ /* SCR=0 */
return header_mpg_found(file_recovery_new);
}
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_mpg)
{
header_ignored(file_recovery_new);
return 0;
}
return header_mpg_found(file_recovery_new);
}
return 0;
}
/*@
@ requires buffer_size >= 12;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@*/
static int header_check_mpg_System(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)
{
/* MPEG-1 http://andrewduncan.ws/MPEG/MPEG-1.ps */
/* ISO/IEC INTERNATIONAL 13818-1 STANDARD
system_header_start_code 32
header_length 16
marker_bit 1
rate_bound 22
marker_bit 1
audio_bound 6
fixed_flag 1
CSPS_flag 1
system_audio_lock_flag 1
system_video_lock_flag 1
marker_bit 1
video_bound 5
packet_rate_restriction_flag 1
reserved_bits 7
*/
/* MPEG-1 system header start code */
if((buffer[6]&0x80)==0x80 && (buffer[8]&0x01)==0x01 && buffer[11]==0xff)
{
if(is_valid_packet_size(buffer, buffer_size)==0)
return 0;
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_mpg)
{
header_ignored(file_recovery_new);
return 0;
}
return header_mpg_found(file_recovery_new);
}
return 0;
}
/*@
@ requires buffer_size >= 11;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@*/
static int header_check_mpg_Sequence(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)
{
/* MPEG-1 sequence header code 0x1B3 */
/* horizontal size>0 */
if((buffer[4]<<4)+(buffer[5]>>4)>0 &&
/* vertical size>0 */
((buffer[5]&0x0f)<<8)+buffer[6]>0 &&
/* aspect_ratio */
(buffer[7]>>4)!=0 && (buffer[7]>>4)!=15 &&
/* picture rate*/
(buffer[7]&0x0f)!=0 && (buffer[7]&0xf)!=15 &&
/* bit rate */
(buffer[8]!=0 || buffer[9]!=0 || (buffer[10]&0xc0)!=0) &&
/* marker */
(buffer[10]&0x20)==0x20)
{
if(is_valid_packet_size(buffer, buffer_size)==0)
return 0;
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_mpg)
{
header_ignored(file_recovery_new);
return 0;
}
return header_mpg_found(file_recovery_new);
}
return 0;
}
/*@
@ requires buffer_size >= 6;
@ requires separation: \separated(&file_hint_mpg, buffer+(..), file_recovery, file_recovery_new);
@ requires valid_header_check_param(buffer, buffer_size, safe_header_only, file_recovery, file_recovery_new);
@ terminates \true;
@ ensures valid_header_check_result(\result, file_recovery_new);
@*/
static int header_check_mpg4_ElemVideo(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)
{
/* ISO/IEC 14496-2 (MPEG-4 video) ELEMENTARY VIDEO HEADER - visual object start code */
/* is_visual_object_identifier */
if((buffer[4]&0xf0)==0x80 &&
/* visual_object_verid */
(((buffer[4]>>3)&0x0f)==1 || ((buffer[4]>>3)&0x0f)==2) &&
/* visual_object_priority */
(buffer[4]&0x7)!=0 &&
/* visual_object_type */
(buffer[5]>>4)!=0 && (buffer[5]>>4)!=0x0f
)
{
if(is_valid_packet_size(buffer, buffer_size)==0)
return 0;
if(file_recovery->file_stat!=NULL &&
file_recovery->file_check!=NULL &&
file_recovery->file_stat->file_hint==&file_hint_mpg)
{
header_ignored(file_recovery_new);
return 0;
}
return header_mpg_found(file_recovery_new);
}
return 0;
}
static void register_header_check_mpg(file_stat_t *file_stat)
{
static const unsigned char mpg_header_B3[4]= {0x00, 0x00, 0x01, 0xB3};
static const unsigned char mpg_header_B5[4]= {0x00, 0x00, 0x01, 0xB5};
static const unsigned char mpg_header_BA[4]= {0x00, 0x00, 0x01, 0xBA};
static const unsigned char mpg_header_BB[4]= {0x00, 0x00, 0x01, 0xBB};
register_header_check(0, mpg_header_B3,sizeof(mpg_header_B3), &header_check_mpg_Sequence, file_stat);
register_header_check(0, mpg_header_B5,sizeof(mpg_header_B5), &header_check_mpg4_ElemVideo, file_stat);
register_header_check(0, mpg_header_BA,sizeof(mpg_header_BA), &header_check_mpg_Pack, file_stat);
register_header_check(0, mpg_header_BB,sizeof(mpg_header_BB), &header_check_mpg_System, file_stat);
}
#endif
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