/usr/share/perl5/Image/ExifTool/Charset.pm is in libimage-exiftool-perl 8.60-2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 | #------------------------------------------------------------------------------
# File: Charset.pm
#
# Description: ExifTool character encoding routines
#
# Revisions: 2009/08/28 - P. Harvey created
# 2010/01/20 - P. Harvey complete re-write
# 2010/07/16 - P. Harvey added UTF-16 support
#------------------------------------------------------------------------------
package Image::ExifTool::Charset;
use strict;
use vars qw($VERSION %csType);
use Image::ExifTool qw(:DataAccess :Utils);
$VERSION = '1.07';
my %charsetTable; # character set tables we've loaded
# lookup for converting Unicode to 1-byte character sets
my %unicode2byte = (
Latin => { # pre-load Latin (cp1252) for speed
0x20ac => 0x80, 0x0160 => 0x8a, 0x2013 => 0x96,
0x201a => 0x82, 0x2039 => 0x8b, 0x2014 => 0x97,
0x0192 => 0x83, 0x0152 => 0x8c, 0x02dc => 0x98,
0x201e => 0x84, 0x017d => 0x8e, 0x2122 => 0x99,
0x2026 => 0x85, 0x2018 => 0x91, 0x0161 => 0x9a,
0x2020 => 0x86, 0x2019 => 0x92, 0x203a => 0x9b,
0x2021 => 0x87, 0x201c => 0x93, 0x0153 => 0x9c,
0x02c6 => 0x88, 0x201d => 0x94, 0x017e => 0x9e,
0x2030 => 0x89, 0x2022 => 0x95, 0x0178 => 0x9f,
},
);
# bit flags for all supported character sets
# (this number must be correct because it dictates the decoding algorithm!)
# 0x001 = character set requires a translation module
# 0x002 = inverse conversion not yet supported by Recompose()
# 0x080 = some characters with codepoints in the range 0x00-0x7f are remapped
# 0x100 = 1-byte fixed-width characters
# 0x200 = 2-byte fixed-width characters
# 0x400 = 4-byte fixed-width characters
# 0x800 = 1- and 2-byte variable-width characters, or 1-byte
# fixed-width characters that map into multiple codepoints
# Note: In its public interface, ExifTool can currently only support type 0x101
# and lower character sets because strings are only converted if they
# contain characters above 0x7f and there is no provision for specifying
# the byte order for input/output values
%csType = (
UTF8 => 0x100,
ASCII => 0x100, # (treated like UTF8)
Arabic => 0x101,
Baltic => 0x101,
Cyrillic => 0x101,
Greek => 0x101,
Hebrew => 0x101,
Latin => 0x101,
Latin2 => 0x101,
MacCroatian => 0x101,
MacCyrillic => 0x101,
MacGreek => 0x101,
MacIceland => 0x101,
MacLatin2 => 0x101,
MacRoman => 0x101,
MacRomanian => 0x101,
MacTurkish => 0x101,
Thai => 0x101,
Turkish => 0x101,
Vietnam => 0x101,
MacArabic => 0x103, # (directional characters not supported)
PDFDoc => 0x181,
Unicode => 0x200, # (UCS2)
UCS2 => 0x200,
UTF16 => 0x200,
Symbol => 0x201,
JIS => 0x201,
UCS4 => 0x400,
MacChineseCN => 0x803,
MacChineseTW => 0x803,
MacHebrew => 0x803, # (directional characters not supported)
MacKorean => 0x803,
MacRSymbol => 0x803,
MacThai => 0x803,
MacJapanese => 0x883,
ShiftJIS => 0x883,
);
#------------------------------------------------------------------------------
# Load character set module
# Inputs: 0) Module name
# Returns: Reference to lookup hash, or undef on error
sub LoadCharset($)
{
my $charset = shift;
my $conv = $charsetTable{$charset};
unless ($conv) {
# load translation module
my $module = "Image::ExifTool::Charset::$charset";
no strict 'refs';
if (%$module or eval "require $module") {
$conv = $charsetTable{$charset} = \%$module;
}
}
return $conv;
}
#------------------------------------------------------------------------------
# Decompose string with specified encoding into an array of integer code points
# Inputs: 0) ExifTool object ref (or undef), 1) string, 2) character set name,
# 3) optional byte order ('II','MM','Unknown' or undef to use ExifTool ordering)
# Returns: Reference to array of Unicode values
# Notes: Accepts any type of character set
# - byte order only used for fixed-width 2-byte and 4-byte character sets
# - byte order mark observed and then removed with UCS2 and UCS4
# - no warnings are issued if ExifTool object is not provided
sub Decompose($$$;$)
{
local $_;
my ($exifTool, $val, $charset) = @_; # ($byteOrder assigned later if required)
my $type = $csType{$charset};
my (@uni, $conv);
if ($type & 0x001) {
$conv = LoadCharset($charset);
unless ($conv) {
# (shouldn't happen)
$exifTool->Warn("Invalid character set $charset") if $exifTool;
return \@uni; # error!
}
} elsif ($type == 0x100) {
# convert ASCII and UTF8 (treat ASCII as UTF8)
if ($] < 5.006001) {
# do it ourself
@uni = Image::ExifTool::UnpackUTF8($val);
} else {
# handle warnings from malformed UTF-8
undef $Image::ExifTool::evalWarning;
local $SIG{'__WARN__'} = \&Image::ExifTool::SetWarning;
# (somehow the meaning of "U0" was reversed in Perl 5.10.0!)
@uni = unpack($] < 5.010000 ? 'U0U*' : 'C0U*', $val);
# issue warning if we had errors
if ($Image::ExifTool::evalWarning and $exifTool and not $$exifTool{WarnBadUTF8}) {
$exifTool->Warn('Malformed UTF-8 character(s)');
$$exifTool{WarnBadUTF8} = 1;
}
}
return \@uni; # all done!
}
if ($type & 0x100) { # 1-byte fixed-width characters
@uni = unpack('C*', $val);
foreach (@uni) {
$_ = $$conv{$_} if defined $$conv{$_};
}
} elsif ($type & 0x600) { # 2-byte or 4-byte fixed-width characters
my $unknown;
my $byteOrder = $_[3];
if (not $byteOrder) {
$byteOrder = GetByteOrder();
} elsif ($byteOrder eq 'Unknown') {
$byteOrder = GetByteOrder();
$unknown = 1;
}
my $fmt = $byteOrder eq 'MM' ? 'n*' : 'v*';
if ($type & 0x400) { # 4-byte
$fmt = uc $fmt; # unpack as 'N*' or 'V*'
# honour BOM if it exists
$val =~ s/^(\0\0\xfe\xff|\xff\xfe\0\0)// and $fmt = $1 eq "\0\0\xfe\xff" ? 'N*' : 'V*';
undef $unknown; # (byte order logic applies to 2-byte only)
} elsif ($val =~ s/^(\xfe\xff|\xff\xfe)//) {
$fmt = $1 eq "\xfe\xff" ? 'n*' : 'v*';
undef $unknown;
}
# convert from UCS2 or UCS4
@uni = unpack($fmt, $val);
if (not $conv) {
# no translation necessary
if ($unknown) {
# check the byte order
my (%bh, %bl);
my ($zh, $zl) = (0, 0);
foreach (@uni) {
$bh{$_ >> 8} = 1;
$bl{$_ & 0xff} = 1;
++$zh unless $_ & 0xff00;
++$zl unless $_ & 0x00ff;
}
# count the number of unique values in the hi and lo bytes
my ($bh, $bl) = (scalar(keys %bh), scalar(keys %bl));
# the byte with the greater number of unique values should be
# the low-order byte, otherwise the byte which is zero more
# often is likely the high-order byte
if ($bh > $bl or ($bh == $bl and $zl > $zh)) {
# we guessed wrong, so decode using the other byte order
$fmt =~ tr/nvNV/vnVN/;
@uni = unpack($fmt, $val);
}
}
# handle surrogate pairs of UTF-16
if ($charset eq 'UTF16') {
my $i;
for ($i=0; $i<$#uni; ++$i) {
next unless ($uni[$i] & 0xfc00) == 0xd800 and
($uni[$i+1] & 0xfc00) == 0xdc00;
my $cp = 0x10000 + (($uni[$i] & 0x3ff) << 10) + ($uni[$i+1] & 0x3ff);
splice(@uni, $i, 2, $cp);
}
}
} elsif ($unknown) {
# count encoding errors as we do the translation
my $e1 = 0;
foreach (@uni) {
defined $$conv{$_} and $_ = $$conv{$_}, next;
++$e1;
}
# try the other byte order if we had any errors
if ($e1) {
$fmt = $byteOrder eq 'MM' ? 'v*' : 'n*'; #(reversed)
my @try = unpack($fmt, $val);
my $e2 = 0;
foreach (@try) {
defined $$conv{$_} and $_ = $$conv{$_}, next;
++$e2;
}
# use this byte order if there are fewer errors
return \@try if $e2 < $e1;
}
} else {
# translate any characters found in the lookup
foreach (@uni) {
$_ = $$conv{$_} if defined $$conv{$_};
}
}
} else { # variable-width characters
# unpack into bytes
my @bytes = unpack('C*', $val);
while (@bytes) {
my $ch = shift @bytes;
my $cv = $$conv{$ch};
# pass straight through if no translation
$cv or push(@uni, $ch), next;
# byte translates into single Unicode character
ref $cv or push(@uni, $cv), next;
# byte maps into multiple Unicode characters
ref $cv eq 'ARRAY' and push(@uni, @$cv), next;
# handle 2-byte character codes
$ch = shift @bytes;
if (defined $ch) {
if ($$cv{$ch}) {
$cv = $$cv{$ch};
ref $cv or push(@uni, $cv), next;
push @uni, @$cv; # multiple Unicode characters
} else {
push @uni, ord('?'); # encoding error
unshift @bytes, $ch;
}
} else {
push @uni, ord('?'); # encoding error
}
}
}
return \@uni;
}
#------------------------------------------------------------------------------
# Convert array of code point integers into a string with specified encoding
# Inputs: 0) ExifTool ref (or undef), 1) unicode character array ref,
# 2) character set (note: not all types are supported)
# 3) byte order ('MM' or 'II', multi-byte sets only, defaults to current byte order)
# Returns: converted string (truncated at null character if it exists), empty on error
# Notes: converts elements of input character array to new code points
# - ExifTool ref may be undef provided $charset is defined
sub Recompose($$;$$)
{
local $_;
my ($exifTool, $uni, $charset) = @_; # ($byteOrder assigned later if required)
my ($outVal, $conv, $inv);
$charset or $charset = $$exifTool{OPTIONS}{Charset};
my $csType = $csType{$charset};
if ($csType == 0x100) { # UTF8 (also treat ASCII as UTF8)
if ($] >= 5.006001) {
# let Perl do it
$outVal = pack('C0U*', @$uni);
} else {
# do it ourself
$outVal = Image::ExifTool::PackUTF8(@$uni);
}
$outVal =~ s/\0.*//s; # truncate at null terminator
return $outVal;
}
# get references to forward and inverse lookup tables
if ($csType & 0x801) {
$conv = LoadCharset($charset);
unless ($conv) {
$exifTool->Warn("Missing charset $charset") if $exifTool;
return '';
}
$inv = $unicode2byte{$charset};
# generate inverse lookup if necessary
unless ($inv) {
if (not $csType or $csType & 0x802) {
$exifTool->Warn("Invalid destination charset $charset") if $exifTool;
return '';
}
# prepare table to convert from Unicode to 1-byte characters
my ($char, %inv);
foreach $char (keys %$conv) {
$inv{$$conv{$char}} = $char;
}
$inv = $unicode2byte{$charset} = \%inv;
}
}
if ($csType & 0x100) { # 1-byte fixed-width
# convert to specified character set
foreach (@$uni) {
next if $_ < 0x80;
$$inv{$_} and $_ = $$inv{$_}, next;
# our tables omit 1-byte characters with the same values as Unicode,
# so pass them straight through after making sure there isn't a
# different character with this byte value
next if $_ < 0x100 and not $$conv{$_};
$_ = ord('?'); # set invalid characters to '?'
if ($exifTool and not $$exifTool{EncodingError}) {
$exifTool->Warn("Some character(s) could not be encoded in $charset");
$$exifTool{EncodingError} = 1;
}
}
# repack as an 8-bit string and truncate at null
$outVal = pack('C*', @$uni);
$outVal =~ s/\0.*//s;
} else { # 2-byte and 4-byte fixed-width
# convert if required
if ($inv) {
$$inv{$_} and $_ = $$inv{$_} foreach @$uni;
}
# generate surrogate pairs of UTF-16
if ($charset eq 'UTF16') {
my $i;
for ($i=0; $i<@$uni; ++$i) {
next unless $$uni[$i] >= 0x10000 and $$uni[$i] < 0x10ffff;
my $t = $$uni[$i] - 0x10000;
my $w1 = 0xd800 + (($t >> 10) & 0x3ff);
my $w2 = 0xdc00 + ($t & 0x3ff);
splice(@$uni, $i, 1, $w1, $w2);
++$i; # skip surrogate pair
}
}
# pack as 2- or 4-byte integer in specified byte order
my $byteOrder = $_[3] || GetByteOrder();
my $fmt = $byteOrder eq 'MM' ? 'n*' : 'v*';
$fmt = uc($fmt) if $csType & 0x400;
$outVal = pack($fmt, @$uni);
}
return $outVal;
}
1; # end
__END__
=head1 NAME
Image::ExifTool::Charset - ExifTool character encoding routines
=head1 SYNOPSIS
This module is required by Image::ExifTool.
=head1 DESCRIPTION
This module contains routines used by ExifTool to translate special
character sets. Currently, the following character sets are supported:
UTF8, UTF16, UCS2, UCS4, Arabic, Baltic, Cyrillic, Greek, Hebrew, JIS,
Latin, Latin2, MacArabic, MacChineseCN, MacChineseTW, MacCroatian,
MacCyrillic, MacGreek, MacHebrew, MacIceland, MacJapanese, MacKorean,
MacLatin2, MacRSymbol, MacRoman, MacRomanian, MacThai, MacTurkish,
PDFDoc, RSymbol, ShiftJIS, Symbol, Thai, Turkish, Vietnam
However, only some of these character sets are available to the user via
ExifTool options; the multi-byte character sets are used only internally
when decoding certain types of information.
=head1 AUTHOR
Copyright 2003-2011, Phil Harvey (phil at owl.phy.queensu.ca)
This library is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
=head1 SEE ALSO
L<Image::ExifTool(3pm)|Image::ExifTool>
=cut
|