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/*
This file is part of libextractor.
(C) 2004, 2009 Vidyut Samanta and Christian Grothoff
libextractor 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, or (at your
option) any later version.
libextractor 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 libextractor; see the file COPYING. If not, write to the
Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.
*/
#include "platform.h"
#include "extractor.h"
#include "pack.h"
#define DEBUG 0
static int
addKeyword (EXTRACTOR_MetaDataProcessor proc,
void *proc_cls,
const char *keyword,
enum EXTRACTOR_MetaType type)
{
if (keyword == NULL)
return 0;
return proc (proc_cls,
"tiff",
type,
EXTRACTOR_METAFORMAT_UTF8,
"text/plain",
keyword,
strlen(keyword)+1);
}
typedef struct
{
unsigned short byteorder;
unsigned short fourty_two;
unsigned int ifd_offset;
} TIFF_HEADER;
#define TIFF_HEADER_SIZE 8
#define TIFF_HEADER_FIELDS(p) \
&(p)->byteorder, \
&(p)->fourty_two, \
&(p)->ifd_offset
static char *TIFF_HEADER_SPECS[] = {
"hhw",
"HHW",
};
typedef struct
{
unsigned short tag;
unsigned short type;
unsigned int count;
unsigned int value_or_offset;
} DIRECTORY_ENTRY;
#define DIRECTORY_ENTRY_SIZE 12
#define DIRECTORY_ENTRY_FIELDS(p) \
&(p)->tag, \
&(p)->type, \
&(p)->count, \
&(p)->value_or_offset
static char *DIRECTORY_ENTRY_SPECS[] = {
"hhww",
"HHWW"
};
#define TAG_LENGTH 0x101
#define TAG_WIDTH 0x100
#define TAG_SOFTWARE 0x131
#define TAG_DAYTIME 0x132
#define TAG_ARTIST 0x315
#define TAG_COPYRIGHT 0x8298
#define TAG_DESCRIPTION 0x10E
#define TAG_DOCUMENT_NAME 0x10D
#define TAG_HOST 0x13C
#define TAG_SCANNER 0x110
#define TAG_ORIENTATION 0x112
#define TYPE_BYTE 1
#define TYPE_ASCII 2
#define TYPE_SHORT 3
#define TYPE_LONG 4
#define TYPE_RATIONAL 5
static int
addASCII (EXTRACTOR_MetaDataProcessor proc,
void *proc_cls,
const char *data,
size_t size, DIRECTORY_ENTRY * entry,
enum EXTRACTOR_MetaType type)
{
if (entry->count > size)
return 0; /* invalid! */
if (entry->type != TYPE_ASCII)
return 0; /* huh? */
if (entry->count + entry->value_or_offset > size)
return 0;
if (data[entry->value_or_offset + entry->count - 1] != 0)
return 0;
return addKeyword (proc, proc_cls,
&data[entry->value_or_offset], type);
}
int
EXTRACTOR_tiff_extract (const char *data,
size_t size,
EXTRACTOR_MetaDataProcessor proc,
void *proc_cls,
const char *options)
{
TIFF_HEADER hdr;
int byteOrder; /* 0: do not convert;
1: do convert */
unsigned int current_ifd;
unsigned int length = -1;
unsigned int width = -1;
if (size < TIFF_HEADER_SIZE)
return 0; /* can not be tiff */
if ((data[0] == 0x49) && (data[1] == 0x49))
byteOrder = 0;
else if ((data[0] == 0x4D) && (data[1] == 0x4D))
byteOrder = 1;
else
return 0; /* can not be tiff */
#if __BYTE_ORDER == __BIG_ENDIAN
byteOrder = 1 - byteOrder;
#endif
EXTRACTOR_common_cat_unpack (data, TIFF_HEADER_SPECS[byteOrder], TIFF_HEADER_FIELDS (&hdr));
if (hdr.fourty_two != 42)
return 0; /* can not be tiff */
if (hdr.ifd_offset + 6 > size)
return 0; /* malformed tiff */
if (0 != addKeyword (proc, proc_cls, "image/tiff", EXTRACTOR_METATYPE_MIMETYPE))
return 1;
current_ifd = hdr.ifd_offset;
while (current_ifd != 0)
{
unsigned short len;
unsigned int off;
int i;
if ( (current_ifd + 6 > size) ||
(current_ifd + 6 < current_ifd) )
return 0;
if (byteOrder == 0)
len = data[current_ifd + 1] << 8 | data[current_ifd];
else
len = data[current_ifd] << 8 | data[current_ifd + 1];
if (len * DIRECTORY_ENTRY_SIZE + 2 + 4 + current_ifd > size)
{
#if DEBUG
printf ("WARNING: malformed tiff\n");
#endif
return 0;
}
for (i = 0; i < len; i++)
{
DIRECTORY_ENTRY entry;
off = current_ifd + 2 + DIRECTORY_ENTRY_SIZE * i;
EXTRACTOR_common_cat_unpack (&data[off],
DIRECTORY_ENTRY_SPECS[byteOrder],
DIRECTORY_ENTRY_FIELDS (&entry));
switch (entry.tag)
{
case TAG_LENGTH:
if ((entry.type == TYPE_SHORT) && (byteOrder == 1))
{
length = entry.value_or_offset >> 16;
}
else
{
length = entry.value_or_offset;
}
if (width != -1)
{
char tmp[128];
snprintf (tmp,
sizeof(tmp), "%ux%u",
width, length);
addKeyword (proc,
proc_cls,
tmp,
EXTRACTOR_METATYPE_IMAGE_DIMENSIONS);
}
break;
case TAG_WIDTH:
if ((entry.type == TYPE_SHORT) && (byteOrder == 1))
width = entry.value_or_offset >> 16;
else
width = entry.value_or_offset;
if (length != -1)
{
char tmp[128];
snprintf (tmp,
sizeof(tmp),
"%ux%u",
width, length);
addKeyword (proc, proc_cls,
tmp,
EXTRACTOR_METATYPE_IMAGE_DIMENSIONS);
}
break;
case TAG_SOFTWARE:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_CREATED_BY_SOFTWARE))
return 1;
break;
case TAG_ARTIST:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_ARTIST))
return 1;
break;
case TAG_DOCUMENT_NAME:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_TITLE))
return 1;
break;
case TAG_COPYRIGHT:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_COPYRIGHT))
return 1;
break;
case TAG_DESCRIPTION:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_DESCRIPTION))
return 1;
break;
case TAG_HOST:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_BUILDHOST))
return 1;
break;
case TAG_SCANNER:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_SOURCE))
return 1;
break;
case TAG_DAYTIME:
if (0 != addASCII (proc, proc_cls, data, size, &entry, EXTRACTOR_METATYPE_CREATION_DATE))
return 1;
break;
}
}
off = current_ifd + 2 + DIRECTORY_ENTRY_SIZE * len;
if (byteOrder == 0)
current_ifd =
data[off + 3] << 24 | data[off + 2] << 16 |
data[off + 1] << 8 | data[off];
else
current_ifd =
data[off] << 24 | data[off + 1] << 16 |
data[off + 2] << 8 | data[off + 3];
}
return 0;
}
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