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#------------------------------------------------------------------------------
# File: Scalado.pm
#
# Description: Read APP4 SCALADO metadata
#
# Revisions: 2013-09-13 - P. Harvey Created
#------------------------------------------------------------------------------
package Image::ExifTool::Scalado;
use strict;
use vars qw($VERSION);
use Image::ExifTool qw(:DataAccess :Utils);
use Image::ExifTool::PLIST;
$VERSION = '1.01';
sub ProcessScalado($$$);
# JPEG APP4 SCALADO tags
%Image::ExifTool::Scalado::Main = (
GROUPS => { 0 => 'APP4', 1 => 'Scalado', 2 => 'Image' },
PROCESS_PROC => \&ProcessScalado,
TAG_PREFIX => 'Scalado',
FORMAT => 'int32s',
NOTES => q{
Tags extracted from the JPEG APP4 "SCALADO" segment found in images from
HTC, LG and Samsung phones. (Presumably written by Scalado mobile software,
L<http://www.scalado.com/>.)
},
SPMO => {
Name => 'DataLength',
Unknown => 1,
},
WDTH => {
Name => 'PreviewImageWidth',
ValueConv => '$val ? abs($val) : undef',
},
HGHT => {
Name => 'PreviewImageHeight',
ValueConv => '$val ? abs($val) : undef',
},
QUAL => {
Name => 'PreviewQuality',
ValueConv => '$val ? abs($val) : undef',
},
# tags not yet decoded with observed values:
# CHKH: 0, various negative values
# CHKL: various negative values
# CLEN: -1024
# CSPC: -2232593
# DATA: (+ve data length)
# HDEC: 0
# MAIN: 0, 60
# META: 24
# SCI0: (+ve data length) often 36
# SCI1: (+ve data length) 36
# SCX0: (+ve data length)
# SCX1: (+ve data length) often 84
# WDEC: 0
# VERS: -131328
);
#------------------------------------------------------------------------------
# Extract information from the JPEG APP4 SCALADO segment
# Inputs: 0) ExifTool object ref, 1) dirInfo ref, 2) tag table ref
# Returns: 1 on success
sub ProcessScalado($$$)
{
my ($et, $dirInfo, $tagTablePtr) = @_;
my $dataPt = $$dirInfo{DataPt};
my $pos = 0;
my $end = length $$dataPt;
my $unknown = $et->Options('Unknown');
$et->VerboseDir('APP4 SCALADO', undef, $end);
SetByteOrder('MM');
for (;;) {
last if $pos + 12 > $end;
my $tag = substr($$dataPt, $pos, 4);
my $ver = Get32u($dataPt, $pos + 4); # (looks like a version for some tags)
if (not $$tagTablePtr{$tag} and $unknown) {
my $name = $tag;
$name =~ tr/-A-Za-z0-9_//dc;
last unless length $name; # stop if tag is garbage
AddTagToTable($tagTablePtr, $tag, {
Name => "Scalado_$name",
Description => "Scalado $name",
Unknown => 1,
});
}
$et->HandleTag($tagTablePtr, $tag, undef,
DataPt => $dataPt,
Start => $pos + 8,
Size => 4,
Extra => ", ver $ver",
);
if ($tag eq 'SPMO') {
my $val = Get32u($dataPt, $pos + 8) ;
if ($ver < 5) { # (I don't have samples for version 3 or 4, so I'm not sure about these)
$end -= $val; # SPMO gives trailer data length
} else {
$end = $val + 12; # SPMO gives length of Scalado directory (excepting this entry)
}
}
$pos += 12;
}
return 1;
}
1; # end
__END__
=head1 NAME
Image::ExifTool::Scalado - Read APP4 SCALADO metadata
=head1 SYNOPSIS
This module is loaded automatically by Image::ExifTool when required.
=head1 DESCRIPTION
This module contains definitions required by Image::ExifTool to read
metadata from the JPEG APP4 SCALADO segment.
=head1 AUTHOR
Copyright 2003-2019, 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::TagNames/Scalado Tags>,
L<Image::ExifTool(3pm)|Image::ExifTool>
=cut
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