409 lines
16 KiB
Perl
409 lines
16 KiB
Perl
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#------------------------------------------------------------------------------
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# File: WritePNG.pl
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#
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# Description: Write PNG meta information
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#
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# Revisions: 09/16/2005 - P. Harvey Created
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#
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# References: 1) http://www.libpng.org/pub/png/spec/1.2/
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#------------------------------------------------------------------------------
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package Image::ExifTool::PNG;
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use strict;
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#------------------------------------------------------------------------------
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# Calculate CRC or update running CRC (ref 1)
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# Inputs: 0) data reference, 1) running crc to update (undef intially)
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# 2) data position (undef for 0), 3) data length (undef for all data),
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# Returns: updated CRC
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my @crcTable;
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sub CalculateCRC($;$$$)
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{
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my ($dataPt, $crc, $pos, $len) = @_;
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$crc = 0 unless defined $crc;
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$pos = 0 unless defined $pos;
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$len = length($$dataPt) - $pos unless defined $len;
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$crc ^= 0xffffffff; # undo 1's complement
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# build lookup table unless done already
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unless (@crcTable) {
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my ($c, $n, $k);
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for ($n=0; $n<256; ++$n) {
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for ($k=0, $c=$n; $k<8; ++$k) {
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$c = ($c & 1) ? 0xedb88320 ^ ($c >> 1) : $c >> 1;
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}
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$crcTable[$n] = $c;
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}
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}
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# calculate the CRC
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foreach (unpack("x${pos}C$len", $$dataPt)) {
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$crc = $crcTable[($crc^$_) & 0xff] ^ ($crc >> 8);
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}
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return $crc ^ 0xffffffff; # return 1's complement
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}
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#------------------------------------------------------------------------------
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# Encode data in ASCII Hex
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# Inputs: 0) input data reference
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# Returns: Hex-encoded data (max 72 chars per line)
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sub HexEncode($)
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{
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my $dataPt = shift;
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my $len = length($$dataPt);
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my $hex = '';
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my $pos;
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for ($pos = 0; $pos < $len; $pos += 36) {
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my $n = $len - $pos;
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$n > 36 and $n = 36;
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$hex .= unpack('H*',substr($$dataPt,$pos,$n)) . "\n";
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}
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return $hex;
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}
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#------------------------------------------------------------------------------
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# Write profile chunk (possibly compressed if Zlib is available)
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# Inputs: 0) outfile, 1) Raw profile type, 2) data ref
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# 3) profile header type (undef if not a text profile)
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# Returns: 1 on success
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sub WriteProfile($$$;$)
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{
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my ($outfile, $rawType, $dataPt, $profile) = @_;
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my ($buff, $prefix, $chunk, $deflate);
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if ($rawType ne $stdCase{exif} and eval { require Compress::Zlib }) {
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$deflate = Compress::Zlib::deflateInit();
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}
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if (not defined $profile) {
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# write ICC profile as compressed iCCP chunk if possible
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if ($rawType eq 'icm') {
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return 0 unless $deflate;
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$chunk = 'iCCP';
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$prefix = "$rawType\0\0";
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} else {
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$chunk = $rawType;
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if ($rawType eq $stdCase{zxif}) {
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$prefix = "\0" . pack('N', length $$dataPt);
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} else {
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$prefix = '';
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}
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}
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if ($deflate) {
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$buff = $deflate->deflate($$dataPt);
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return 0 unless defined $buff;
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$buff .= $deflate->flush();
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$dataPt = \$buff;
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}
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} else {
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# write as ASCII-hex encoded profile in tEXt or zTXt chunk
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my $txtHdr = sprintf("\n$profile profile\n%8d\n", length($$dataPt));
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$buff = $txtHdr . HexEncode($dataPt);
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$chunk = 'tEXt'; # write as tEXt if deflate not available
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$prefix = "Raw profile type $rawType\0";
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$dataPt = \$buff;
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# write profile as zTXt chunk if possible
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if ($deflate) {
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my $buf2 = $deflate->deflate($buff);
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if (defined $buf2) {
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$dataPt = \$buf2;
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$buf2 .= $deflate->flush();
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$chunk = 'zTXt';
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$prefix .= "\0"; # compression type byte (0=deflate)
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}
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}
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}
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my $hdr = pack('Na4', length($prefix) + length($$dataPt), $chunk) . $prefix;
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my $crc = CalculateCRC(\$hdr, undef, 4);
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$crc = CalculateCRC($dataPt, $crc);
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return Write($outfile, $hdr, $$dataPt, pack('N',$crc));
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}
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#------------------------------------------------------------------------------
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# Add iCCP to the PNG image if necessary (must come before PLTE and IDAT)
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# Inputs: 0) ExifTool object ref, 1) output file or scalar ref
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# Returns: true on success
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sub Add_iCCP($$)
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{
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my ($et, $outfile) = @_;
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if ($$et{ADD_DIRS}{ICC_Profile}) {
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# write new ICC data
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my $tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::ICC_Profile::Main');
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my %dirInfo = ( Parent => 'PNG', DirName => 'ICC_Profile' );
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my $buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr);
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if (defined $buff and length $buff and WriteProfile($outfile, 'icm', \$buff)) {
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$et->VPrint(0, "Created ICC profile\n");
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delete $$et{ADD_DIRS}{ICC_Profile}; # don't add it again
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$$et{PNGDoneDir}{ICC_Profile} = 2;
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}
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}
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return 1;
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}
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#------------------------------------------------------------------------------
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# This routine is called after we edit an existing directory
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# Inputs: 0) ExifTool ref, 1) dir name, 2) output data ref
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# 3) flag set if location is non-standard (to update, but not create from scratch)
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# - on return, $$outBuff is set to '' if the directory is to be deleted
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sub DoneDir($$$;$)
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{
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my ($et, $dir, $outBuff, $nonStandard) = @_;
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$dir = 'IFD0' if $dir eq 'EXIF';
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# don't add this directory again unless this is in a non-standard location
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delete $$et{ADD_DIRS}{$dir} unless $nonStandard;
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# handle problem with duplicate XMP when using PNGEarlyXMP option
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return unless $dir eq 'XMP' and defined $$outBuff and length $$outBuff;
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if ($nonStandard and $$et{DEL_GROUP}{$dir}) {
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$et->VPrint(0," Deleting non-standard $dir\n");
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$$outBuff = '';
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} elsif (not $$et{PNGDoneDir}{$dir}) {
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$$et{PNGDoneDir}{$dir} = 1; # set flag indicating the directory exists
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} elsif ($$et{OPTIONS}{PNGEarlyXMP}) {
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if ($$et{PNGDoneDir}{$dir} == 2) {
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if ($$et{OPTIONS}{IgnoreMinorErrors}) {
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$et->Warn("Deleted existing $dir");
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} else {
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$et->Error("Duplicate $dir created. Ignore to delete existing $dir", 1);
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return;
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}
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} elsif ($et->Warn("Duplicate $dir. Ignore to delete", 2)) {
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return; # warning not ignored: don't delete the duplicate
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}
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$et->VPrint(0," Deleting duplicate $dir\n");
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$$outBuff = '';
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}
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}
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#------------------------------------------------------------------------------
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# Generate tEXt, zTXt or iTXt data for writing
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# Inputs: 0) ExifTool ref, 1) tagID, 2) tagInfo ref, 3) value string, 4) language code
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# Returns: chunk data (not including 8-byte chunk header)
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# Notes: Sets ExifTool TextChunkType member to the type of chunk written
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sub BuildTextChunk($$$$$)
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{
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my ($et, $tag, $tagInfo, $val, $lang) = @_;
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my ($xtra, $compVal, $iTXt, $comp);
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if ($$tagInfo{SubDirectory}) {
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if ($$tagInfo{Name} eq 'XMP') {
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$iTXt = 2; # write as iTXt but flag to avoid encoding
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# (never compress XMP)
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} else {
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$comp = 2; # compress raw profile if possible
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}
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} else {
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# compress if specified
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$comp = 1 if $et->Options('Compress');
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if ($lang) {
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$iTXt = 1; # write as iTXt if it has a language code
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$tag =~ s/-$lang$//; # remove language code from tagID
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} elsif ($$et{OPTIONS}{Charset} ne 'Latin' and $val =~ /[\x80-\xff]/) {
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$iTXt = 1; # write as iTXt if it contains non-Latin special characters
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}
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}
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if ($comp) {
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my $warn;
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if (eval { require Compress::Zlib }) {
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my $deflate = Compress::Zlib::deflateInit();
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$compVal = $deflate->deflate($val) if $deflate;
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if (defined $compVal) {
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$compVal .= $deflate->flush();
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# only compress if it actually saves space
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unless (length($compVal) < length($val)) {
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undef $compVal;
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$warn = 'uncompressed data is smaller';
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}
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} else {
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$warn = 'deflate error';
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}
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} else {
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$warn = 'Compress::Zlib not available';
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}
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# warn if any user-specified compression fails
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if ($warn and $comp == 1) {
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$et->Warn("PNG:$$tagInfo{Name} not compressed ($warn)", 1);
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}
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}
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# decide whether to write as iTXt, zTXt or tEXt
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if ($iTXt) {
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$$et{TextChunkType} = 'iTXt';
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$xtra = (defined $compVal ? "\x01\0" : "\0\0") . ($lang || '') . "\0\0";
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# iTXt is encoded as UTF-8 (but note that XMP is already UTF-8)
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$val = $et->Encode($val, 'UTF8') if $iTXt == 1;
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} elsif (defined $compVal) {
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$$et{TextChunkType} = 'zTXt';
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$xtra = "\0";
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} else {
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$$et{TextChunkType} = 'tEXt';
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$xtra = '';
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}
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return $tag . "\0" . $xtra . (defined $compVal ? $compVal : $val);
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}
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#------------------------------------------------------------------------------
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# Add any outstanding new chunks to the PNG image
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# Inputs: 0) ExifTool object ref, 1) output file or scalar ref
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# 2-N) dirs to add (empty to add all, including PNG tags)
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# Returns: true on success
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sub AddChunks($$;@)
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{
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my ($et, $outfile, @add) = @_;
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my ($addTags, $tag, $dir, $err, $tagTablePtr);
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if (@add) {
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$addTags = { }; # don't add any PNG tags
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} else {
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$addTags = $$et{ADD_PNG}; # add all PNG tags...
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delete $$et{ADD_PNG}; # ...once
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# add all directories
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@add = sort keys %{$$et{ADD_DIRS}};
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}
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# write any outstanding PNG tags
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foreach $tag (sort keys %$addTags) {
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my $tagInfo = $$addTags{$tag};
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my $nvHash = $et->GetNewValueHash($tagInfo);
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# (native PNG information is always preferred, so don't check IsCreating)
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next unless $et->IsOverwriting($nvHash);
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my $val = $et->GetNewValue($nvHash);
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if (defined $val) {
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next if $$nvHash{EditOnly};
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my $data;
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if ($$tagInfo{Table} eq \%Image::ExifTool::PNG::TextualData) {
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$data = BuildTextChunk($et, $tag, $tagInfo, $val, $$tagInfo{LangCode});
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$data = $$et{TextChunkType} . $data;
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delete $$et{TextChunkType};
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} else {
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$data = "$tag$val";
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}
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my $hdr = pack('N', length($data) - 4);
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my $cbuf = pack('N', CalculateCRC(\$data, undef));
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Write($outfile, $hdr, $data, $cbuf) or $err = 1;
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$et->VerboseValue("+ PNG:$$tagInfo{Name}", $val);
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$$et{PNGDoneTag}{$tag} = 1; # set flag indicating this tag was added
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++$$et{CHANGED};
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}
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}
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# create any necessary directories
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foreach $dir (@add) {
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next unless $$et{ADD_DIRS}{$dir}; # make sure we want to add it first
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my $buff;
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my %dirInfo = (
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Parent => 'PNG',
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DirName => $dir,
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);
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if ($dir eq 'IFD0') {
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my $chunk = $stdCase{exif};
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# (zxIf was not adopted)
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#if ($et->Options('Compress')) {
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# if (eval { require Compress::Zlib }) {
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# $chunk = $stdCase{zxif};
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# } else {
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# $et->Warn("Creating uncompressed $stdCase{exif} chunk (Compress::Zlib not available)");
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# }
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#}
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$et->VPrint(0, "Creating $chunk chunk:\n");
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$$et{TIFF_TYPE} = 'APP1';
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$tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::Exif::Main');
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$buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr, \&Image::ExifTool::WriteTIFF);
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if (defined $buff and length $buff) {
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WriteProfile($outfile, $chunk, \$buff) or $err = 1;
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}
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} elsif ($dir eq 'XMP') {
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$et->VPrint(0, "Creating XMP iTXt chunk:\n");
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$tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::XMP::Main');
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$dirInfo{ReadOnly} = 1;
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$buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr);
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if (defined $buff and length $buff and
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# the packet is read-only (because of CRC)
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Image::ExifTool::XMP::ValidateXMP(\$buff, 'r'))
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{
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# (previously, XMP was created as a non-standard XMP profile chunk)
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# $buff = $Image::ExifTool::xmpAPP1hdr . $buff;
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# WriteProfile($outfile, 'APP1', \$buff, 'generic') or $err = 1;
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# (but now write XMP iTXt chunk according to XMP specification)
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$buff = "iTXtXML:com.adobe.xmp\0\0\0\0\0" . $buff;
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my $hdr = pack('N', length($buff) - 4);
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my $cbuf = pack('N', CalculateCRC(\$buff, undef));
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Write($outfile, $hdr, $buff, $cbuf) or $err = 1;
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}
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} elsif ($dir eq 'IPTC') {
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$et->Warn('Creating non-standard EXIF in PNG', 1);
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$et->VPrint(0, "Creating IPTC profile:\n");
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# write new IPTC data (stored in a Photoshop directory)
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$dirInfo{DirName} = 'Photoshop';
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$tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::Photoshop::Main');
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$buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr);
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if (defined $buff and length $buff) {
|
||
|
|
WriteProfile($outfile, 'iptc', \$buff, 'IPTC') or $err = 1;
|
||
|
|
}
|
||
|
|
} elsif ($dir eq 'ICC_Profile') {
|
||
|
|
$et->VPrint(0, "Creating ICC profile:\n");
|
||
|
|
# write new ICC data (only done if we couldn't create iCCP chunk)
|
||
|
|
$tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::ICC_Profile::Main');
|
||
|
|
$buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr);
|
||
|
|
if (defined $buff and length $buff) {
|
||
|
|
WriteProfile($outfile, 'icm', \$buff, 'ICC') or $err = 1;
|
||
|
|
$et->Warn('Wrote ICC as a raw profile (no Compress::Zlib)');
|
||
|
|
}
|
||
|
|
} elsif ($dir eq 'PNG-pHYs') {
|
||
|
|
$et->VPrint(0, "Creating pHYs chunk:\n");
|
||
|
|
$tagTablePtr = Image::ExifTool::GetTagTable('Image::ExifTool::PNG::PhysicalPixel');
|
||
|
|
my $blank = "\0\0\x0b\x12\0\0\x0b\x12\x01"; # 2834 pixels per meter (72 dpi)
|
||
|
|
$dirInfo{DataPt} = \$blank;
|
||
|
|
$buff = $et->WriteDirectory(\%dirInfo, $tagTablePtr);
|
||
|
|
if (defined $buff and length $buff) {
|
||
|
|
$buff = 'pHYs' . $buff; # CRC includes chunk name
|
||
|
|
my $hdr = pack('N', length($buff) - 4);
|
||
|
|
my $cbuf = pack('N', CalculateCRC(\$buff, undef));
|
||
|
|
Write($outfile, $hdr, $buff, $cbuf) or $err = 1;
|
||
|
|
}
|
||
|
|
} else {
|
||
|
|
next;
|
||
|
|
}
|
||
|
|
delete $$et{ADD_DIRS}{$dir}; # don't add again
|
||
|
|
# keep track of the directories that we added
|
||
|
|
$$et{PNGDoneDir}{$dir} = 2 if defined $buff and length $buff;
|
||
|
|
}
|
||
|
|
return not $err;
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
1; # end
|
||
|
|
|
||
|
|
__END__
|
||
|
|
|
||
|
|
=head1 NAME
|
||
|
|
|
||
|
|
Image::ExifTool::WritePNG.pl - Write PNG meta information
|
||
|
|
|
||
|
|
=head1 SYNOPSIS
|
||
|
|
|
||
|
|
These routines are autoloaded by Image::ExifTool::PNG.
|
||
|
|
|
||
|
|
=head1 DESCRIPTION
|
||
|
|
|
||
|
|
This file contains routines to write PNG metadata.
|
||
|
|
|
||
|
|
=head1 NOTES
|
||
|
|
|
||
|
|
Compress::Zlib is required to write compressed text.
|
||
|
|
|
||
|
|
Existing text tags are always rewritten in their original form (compressed
|
||
|
|
zTXt, uncompressed tEXt or international iTXt), so pre-existing compressed
|
||
|
|
information can only be modified if Compress::Zlib is available.
|
||
|
|
|
||
|
|
Newly created textual information is written in uncompressed tEXt form by
|
||
|
|
default, or as compressed zTXt if the Compress option is used and
|
||
|
|
Compress::Zlib is available (but only if the resulting compressed data is
|
||
|
|
smaller than the original text, which isn't always the case for short text
|
||
|
|
strings).
|
||
|
|
|
||
|
|
=head1 AUTHOR
|
||
|
|
|
||
|
|
Copyright 2003-2018, 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::PNG(3pm)|Image::ExifTool::PNG>,
|
||
|
|
L<Image::ExifTool(3pm)|Image::ExifTool>
|
||
|
|
|
||
|
|
=cut
|