package PDF::API2::Resource::XObject::Image::GIF;
our $VERSION = '2.019';
use base 'PDF::API2::Resource::XObject::Image';
use IO::File;
use PDF::API2::Util;
use PDF::API2::Basic::PDF::Utils;
no warnings qw[ deprecated recursion uninitialized ];
# added from PDF::Create:
# PDF::Image::GIFImage - GIF image support
# Author: Michael Gross <mdgrosse@sbox.tugraz.at>
# modified for internal use. (c) 2004 fredo.
sub unInterlace {
my $self = shift;
my $data = $self->{' stream'};
my $row;
my @result;
my $width = $self->width;
my $height = $self->height;
my $idx = 0;
#Pass 1 - every 8th row, starting with row 0
$row = 0;
while ($row < $height) {
$result[$row] = substr($data, $idx*$width, $width);
$row+=8;
$idx++;
}
#Pass 2 - every 8th row, starting with row 4
$row = 4;
while ($row < $height) {
$result[$row] = substr($data, $idx*$width, $width);
$row+=8;
$idx++;
}
#Pass 3 - every 4th row, starting with row 2
$row = 2;
while ($row < $height) {
$result[$row] = substr($data, $idx*$width, $width);
$row+=4;
$idx++;
}
#Pass 4 - every 2th row, starting with row 1
$row = 1;
while ($row < $height) {
$result[$row] = substr($data, $idx*$width, $width);
$row+=2;
$idx++;
}
$self->{' stream'}=join('', @result);
}
sub deGIF {
my ($ibits,$stream)=@_;
my $bits=$ibits;
my $resetcode=1<<($ibits-1);
my $endcode=$resetcode+1;
my $nextcode=$endcode+1;
my $ptr=0;
my $maxptr=8*length($stream);
my $tag;
my $out='';
my $outptr=0;
# print STDERR "reset=$resetcode\nend=$endcode\nmax=$maxptr\n";
my @d=map { chr($_) } (0..$resetcode-1);
while(($ptr+$bits)<=$maxptr) {
$tag=0;
foreach my $off (reverse 0..$bits-1) {
$tag<<=1;
$tag|=vec($stream,$ptr+$off,1);
}
# foreach my $off (0..$bits-1) {
# $tag<<=1;
# $tag|=vec($stream,$ptr+$off,1);
# }
# print STDERR "ptr=$ptr,tag=$tag,bits=$bits,next=$nextcode\n";
# print STDERR "tag to large\n" if($tag>$nextcode);
$ptr+=$bits;
$bits++ if($nextcode == (1<<$bits));
if($tag==$resetcode) {
$bits=$ibits;
$nextcode=$endcode+1;
next;
} elsif($tag==$endcode) {
last;
} elsif($tag<$resetcode) {
$d[$nextcode]=$d[$tag];
$out.=$d[$nextcode];
$nextcode++;
} elsif($tag>$endcode) {
$d[$nextcode]=$d[$tag];
$d[$nextcode].=substr($d[$tag+1],0,1);
$out.=$d[$nextcode];
$nextcode++;
}
}
return($out);
}
sub new {
my ($class,$pdf,$file,$name,%opts) = @_;
my $self;
my $inter=0;
$class = ref $class if ref $class;
$self=$class->SUPER::new($pdf,$name || 'Gx'.pdfkey());
$pdf->new_obj($self) unless($self->is_obj($pdf));
$self->{' apipdf'}=$pdf;
my $fh = IO::File->new;
open($fh,$file);
binmode($fh,':raw');
my $buf;
$fh->read($buf,6); # signature
die "unknown image signature '$buf' -- not a gif." unless($buf=~/^GIF[0-9][0-9][a-b]/);
$fh->read($buf,7); # logical descr.
my($wg,$hg,$flags,$bgColorIndex,$aspect)=unpack('vvCCC',$buf);
if($flags&0x80) {
my $colSize=2**(($flags&0x7)+1);
my $dict=PDFDict();
$pdf->new_obj($dict);
$self->colorspace(PDFArray(PDFName('Indexed'),PDFName('DeviceRGB'),PDFNum($colSize-1),$dict));
$fh->read($dict->{' stream'},3*$colSize); # color-table
}
while(!$fh->eof) {
$fh->read($buf,1); # tag.
my $sep=unpack('C',$buf);
if($sep==0x2C){
$fh->read($buf,9); # image-descr.
my ($left,$top,$w,$h,$flags)=unpack('vvvvC',$buf);
$self->width($w||$wg);
$self->height($h||$hg);
$self->bpc(8);
if($flags&0x80) { # local colormap
my $colSize=2**(($flags&0x7)+1);
my $dict=PDFDict();
$pdf->new_obj($dict);
$self->colorspace(PDFArray(PDFName('Indexed'),PDFName('DeviceRGB'),PDFNum($colSize-1),$dict));
$fh->read($dict->{' stream'},3*$colSize); # color-table
}
if($flags&0x40) { # need de-interlace
$inter=1;
}
$fh->read($buf,1); # image-lzw-start (should be 9).
my ($sep)=unpack('C',$buf);
$fh->read($buf,1); # first chunk.
my ($len)=unpack('C',$buf);
my $stream='';
while($len>0) {
$fh->read($buf,$len);
$stream.=$buf;
$fh->read($buf,1);
$len=unpack('C',$buf);
}
$self->{' stream'}=deGIF($sep+1,$stream);
$self->unInterlace if($inter);
last;
} elsif($sep==0x3b) {
last;
} elsif($sep==0x21) {
# Graphic Control Extension
$fh->read($buf,1); # tag.
my $tag=unpack('C',$buf);
die "unsupported graphic control extension ($tag)" unless($tag==0xF9);
$fh->read($buf,1); # len.
my $len=unpack('C',$buf);
my $stream='';
while($len>0) {
$fh->read($buf,$len);
$stream.=$buf;
$fh->read($buf,1);
$len=unpack('C',$buf);
}
my ($cFlags,$delay,$transIndex)=unpack('CvC',$stream);
if(($cFlags&0x01) && !$opts{-notrans}) {
$self->{Mask}=PDFArray(PDFNum($transIndex),PDFNum($transIndex));
}
} else {
# extension
$fh->read($buf,1); # tag.
my $tag=unpack('C',$buf);
$fh->read($buf,1); # tag.
my $len=unpack('C',$buf);
while($len>0) {
$fh->read($buf,$len);
$fh->read($buf,1);
$len=unpack('C',$buf);
}
}
}
$fh->close;
$self->filters('FlateDecode');
return($self);
}
sub new_api {
my ($class,$api,@opts)=@_;
my $obj=$class->new($api->{pdf},@opts);
$obj->{' api'}=$api;
return($obj);
}
1;