mirror of
https://github.com/vdm-io/tcpdf.git
synced 2024-12-31 11:51:46 +00:00
482 lines
14 KiB
PHP
482 lines
14 KiB
PHP
<?php
|
|
//============================================================+
|
|
// File name : tcpdf_filters.php
|
|
// Version : 1.0.001
|
|
// Begin : 2011-05-23
|
|
// Last Update : 2014-04-25
|
|
// Author : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com
|
|
// License : GNU-LGPL v3 (http://www.gnu.org/copyleft/lesser.html)
|
|
// -------------------------------------------------------------------
|
|
// Copyright (C) 2011-2013 Nicola Asuni - Tecnick.com LTD
|
|
//
|
|
// This file is part of TCPDF software library.
|
|
//
|
|
// TCPDF is free software: you can redistribute it and/or modify it
|
|
// under the terms of the GNU Lesser General Public License as
|
|
// published by the Free Software Foundation, either version 3 of the
|
|
// License, or (at your option) any later version.
|
|
//
|
|
// TCPDF 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 Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the License
|
|
// along with TCPDF. If not, see
|
|
// <http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT>.
|
|
//
|
|
// See LICENSE.TXT file for more information.
|
|
// -------------------------------------------------------------------
|
|
//
|
|
// Description : This is a PHP class for decoding common PDF filters (PDF 32000-2008 - 7.4 Filters).
|
|
//
|
|
//============================================================+
|
|
|
|
/**
|
|
* @file
|
|
* This is a PHP class for decoding common PDF filters (PDF 32000-2008 - 7.4 Filters).<br>
|
|
* @package com.tecnick.tcpdf
|
|
* @author Nicola Asuni
|
|
* @version 1.0.001
|
|
*/
|
|
|
|
/**
|
|
* @class TCPDF_FILTERS
|
|
* This is a PHP class for decoding common PDF filters (PDF 32000-2008 - 7.4 Filters).<br>
|
|
* @package com.tecnick.tcpdf
|
|
* @brief This is a PHP class for decoding common PDF filters.
|
|
* @version 1.0.001
|
|
* @author Nicola Asuni - info@tecnick.com
|
|
*/
|
|
class TCPDF_FILTERS {
|
|
|
|
/**
|
|
* Define a list of available filter decoders.
|
|
* @private static
|
|
*/
|
|
private static $available_filters = array('ASCIIHexDecode', 'ASCII85Decode', 'LZWDecode', 'FlateDecode', 'RunLengthDecode');
|
|
|
|
// -----------------------------------------------------------------------------
|
|
|
|
/**
|
|
* Get a list of available decoding filters.
|
|
* @return array Array of available filter decoders.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function getAvailableFilters() {
|
|
return self::$available_filters;
|
|
}
|
|
|
|
/**
|
|
* Decode data using the specified filter type.
|
|
* @param string $filter Filter name.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilter($filter, $data) {
|
|
switch ($filter) {
|
|
case 'ASCIIHexDecode': {
|
|
return self::decodeFilterASCIIHexDecode($data);
|
|
break;
|
|
}
|
|
case 'ASCII85Decode': {
|
|
return self::decodeFilterASCII85Decode($data);
|
|
break;
|
|
}
|
|
case 'LZWDecode': {
|
|
return self::decodeFilterLZWDecode($data);
|
|
break;
|
|
}
|
|
case 'FlateDecode': {
|
|
return self::decodeFilterFlateDecode($data);
|
|
break;
|
|
}
|
|
case 'RunLengthDecode': {
|
|
return self::decodeFilterRunLengthDecode($data);
|
|
break;
|
|
}
|
|
case 'CCITTFaxDecode': {
|
|
return self::decodeFilterCCITTFaxDecode($data);
|
|
break;
|
|
}
|
|
case 'JBIG2Decode': {
|
|
return self::decodeFilterJBIG2Decode($data);
|
|
break;
|
|
}
|
|
case 'DCTDecode': {
|
|
return self::decodeFilterDCTDecode($data);
|
|
break;
|
|
}
|
|
case 'JPXDecode': {
|
|
return self::decodeFilterJPXDecode($data);
|
|
break;
|
|
}
|
|
case 'Crypt': {
|
|
return self::decodeFilterCrypt($data);
|
|
break;
|
|
}
|
|
default: {
|
|
return self::decodeFilterStandard($data);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
// --- FILTERS (PDF 32000-2008 - 7.4 Filters) ------------------------------
|
|
|
|
/**
|
|
* Standard
|
|
* Default decoding filter (leaves data unchanged).
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterStandard($data) {
|
|
return $data;
|
|
}
|
|
|
|
/**
|
|
* ASCIIHexDecode
|
|
* Decodes data encoded in an ASCII hexadecimal representation, reproducing the original binary data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterASCIIHexDecode($data) {
|
|
// initialize string to return
|
|
$decoded = '';
|
|
// all white-space characters shall be ignored
|
|
$data = preg_replace('/[\s]/', '', $data);
|
|
// check for EOD character: GREATER-THAN SIGN (3Eh)
|
|
$eod = strpos($data, '>');
|
|
if ($eod !== false) {
|
|
// remove EOD and extra data (if any)
|
|
$data = substr($data, 0, $eod);
|
|
$eod = true;
|
|
}
|
|
// get data length
|
|
$data_length = strlen($data);
|
|
if (($data_length % 2) != 0) {
|
|
// odd number of hexadecimal digits
|
|
if ($eod) {
|
|
// EOD shall behave as if a 0 (zero) followed the last digit
|
|
$data = substr($data, 0, -1).'0'.substr($data, -1);
|
|
} else {
|
|
self::Error('decodeFilterASCIIHexDecode: invalid code');
|
|
}
|
|
}
|
|
// check for invalid characters
|
|
if (preg_match('/[^a-fA-F\d]/', $data) > 0) {
|
|
self::Error('decodeFilterASCIIHexDecode: invalid code');
|
|
}
|
|
// get one byte of binary data for each pair of ASCII hexadecimal digits
|
|
$decoded = pack('H*', $data);
|
|
return $decoded;
|
|
}
|
|
|
|
/**
|
|
* ASCII85Decode
|
|
* Decodes data encoded in an ASCII base-85 representation, reproducing the original binary data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterASCII85Decode($data) {
|
|
// initialize string to return
|
|
$decoded = '';
|
|
// all white-space characters shall be ignored
|
|
$data = preg_replace('/[\s]/', '', $data);
|
|
// remove start sequence 2-character sequence <~ (3Ch)(7Eh)
|
|
if (strpos($data, '<~') !== false) {
|
|
// remove EOD and extra data (if any)
|
|
$data = substr($data, 2);
|
|
}
|
|
// check for EOD: 2-character sequence ~> (7Eh)(3Eh)
|
|
$eod = strpos($data, '~>');
|
|
if ($eod !== false) {
|
|
// remove EOD and extra data (if any)
|
|
$data = substr($data, 0, $eod);
|
|
}
|
|
// data length
|
|
$data_length = strlen($data);
|
|
// check for invalid characters
|
|
if (preg_match('/[^\x21-\x75,\x74]/', $data) > 0) {
|
|
self::Error('decodeFilterASCII85Decode: invalid code');
|
|
}
|
|
// z sequence
|
|
$zseq = chr(0).chr(0).chr(0).chr(0);
|
|
// position inside a group of 4 bytes (0-3)
|
|
$group_pos = 0;
|
|
$tuple = 0;
|
|
$pow85 = array((85*85*85*85), (85*85*85), (85*85), 85, 1);
|
|
$last_pos = ($data_length - 1);
|
|
// for each byte
|
|
for ($i = 0; $i < $data_length; ++$i) {
|
|
// get char value
|
|
$char = ord($data[$i]);
|
|
if ($char == 122) { // 'z'
|
|
if ($group_pos == 0) {
|
|
$decoded .= $zseq;
|
|
} else {
|
|
self::Error('decodeFilterASCII85Decode: invalid code');
|
|
}
|
|
} else {
|
|
// the value represented by a group of 5 characters should never be greater than 2^32 - 1
|
|
$tuple += (($char - 33) * $pow85[$group_pos]);
|
|
if ($group_pos == 4) {
|
|
$decoded .= chr($tuple >> 24).chr($tuple >> 16).chr($tuple >> 8).chr($tuple);
|
|
$tuple = 0;
|
|
$group_pos = 0;
|
|
} else {
|
|
++$group_pos;
|
|
}
|
|
}
|
|
}
|
|
if ($group_pos > 1) {
|
|
$tuple += $pow85[($group_pos - 1)];
|
|
}
|
|
// last tuple (if any)
|
|
switch ($group_pos) {
|
|
case 4: {
|
|
$decoded .= chr($tuple >> 24).chr($tuple >> 16).chr($tuple >> 8);
|
|
break;
|
|
}
|
|
case 3: {
|
|
$decoded .= chr($tuple >> 24).chr($tuple >> 16);
|
|
break;
|
|
}
|
|
case 2: {
|
|
$decoded .= chr($tuple >> 24);
|
|
break;
|
|
}
|
|
case 1: {
|
|
self::Error('decodeFilterASCII85Decode: invalid code');
|
|
break;
|
|
}
|
|
}
|
|
return $decoded;
|
|
}
|
|
|
|
/**
|
|
* LZWDecode
|
|
* Decompresses data encoded using the LZW (Lempel-Ziv-Welch) adaptive compression method, reproducing the original text or binary data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterLZWDecode($data) {
|
|
// initialize string to return
|
|
$decoded = '';
|
|
// data length
|
|
$data_length = strlen($data);
|
|
// convert string to binary string
|
|
$bitstring = '';
|
|
for ($i = 0; $i < $data_length; ++$i) {
|
|
$bitstring .= sprintf('%08b', ord($data[$i]));
|
|
}
|
|
// get the number of bits
|
|
$data_length = strlen($bitstring);
|
|
// initialize code length in bits
|
|
$bitlen = 9;
|
|
// initialize dictionary index
|
|
$dix = 258;
|
|
// initialize the dictionary (with the first 256 entries).
|
|
$dictionary = array();
|
|
for ($i = 0; $i < 256; ++$i) {
|
|
$dictionary[$i] = chr($i);
|
|
}
|
|
// previous val
|
|
$prev_index = 0;
|
|
// while we encounter EOD marker (257), read code_length bits
|
|
while (($data_length > 0) AND (($index = bindec(substr($bitstring, 0, $bitlen))) != 257)) {
|
|
// remove read bits from string
|
|
$bitstring = substr($bitstring, $bitlen);
|
|
// update number of bits
|
|
$data_length -= $bitlen;
|
|
if ($index == 256) { // clear-table marker
|
|
// reset code length in bits
|
|
$bitlen = 9;
|
|
// reset dictionary index
|
|
$dix = 258;
|
|
$prev_index = 256;
|
|
// reset the dictionary (with the first 256 entries).
|
|
$dictionary = array();
|
|
for ($i = 0; $i < 256; ++$i) {
|
|
$dictionary[$i] = chr($i);
|
|
}
|
|
} elseif ($prev_index == 256) {
|
|
// first entry
|
|
$decoded .= $dictionary[$index];
|
|
$prev_index = $index;
|
|
} else {
|
|
// check if index exist in the dictionary
|
|
if ($index < $dix) {
|
|
// index exist on dictionary
|
|
$decoded .= $dictionary[$index];
|
|
$dic_val = $dictionary[$prev_index].$dictionary[$index][0];
|
|
// store current index
|
|
$prev_index = $index;
|
|
} else {
|
|
// index do not exist on dictionary
|
|
$dic_val = $dictionary[$prev_index].$dictionary[$prev_index][0];
|
|
$decoded .= $dic_val;
|
|
}
|
|
// update dictionary
|
|
$dictionary[$dix] = $dic_val;
|
|
++$dix;
|
|
// change bit length by case
|
|
if ($dix == 2047) {
|
|
$bitlen = 12;
|
|
} elseif ($dix == 1023) {
|
|
$bitlen = 11;
|
|
} elseif ($dix == 511) {
|
|
$bitlen = 10;
|
|
}
|
|
}
|
|
}
|
|
return $decoded;
|
|
}
|
|
|
|
/**
|
|
* FlateDecode
|
|
* Decompresses data encoded using the zlib/deflate compression method, reproducing the original text or binary data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterFlateDecode($data) {
|
|
// initialize string to return
|
|
$decoded = @gzuncompress($data);
|
|
if ($decoded === false) {
|
|
self::Error('decodeFilterFlateDecode: invalid code');
|
|
}
|
|
return $decoded;
|
|
}
|
|
|
|
/**
|
|
* RunLengthDecode
|
|
* Decompresses data encoded using a byte-oriented run-length encoding algorithm.
|
|
* @param string $data Data to decode.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterRunLengthDecode($data) {
|
|
// initialize string to return
|
|
$decoded = '';
|
|
// data length
|
|
$data_length = strlen($data);
|
|
$i = 0;
|
|
while($i < $data_length) {
|
|
// get current byte value
|
|
$byte = ord($data[$i]);
|
|
if ($byte == 128) {
|
|
// a length value of 128 denote EOD
|
|
break;
|
|
} elseif ($byte < 128) {
|
|
// if the length byte is in the range 0 to 127
|
|
// the following length + 1 (1 to 128) bytes shall be copied literally during decompression
|
|
$decoded .= substr($data, ($i + 1), ($byte + 1));
|
|
// move to next block
|
|
$i += ($byte + 2);
|
|
} else {
|
|
// if length is in the range 129 to 255,
|
|
// the following single byte shall be copied 257 - length (2 to 128) times during decompression
|
|
$decoded .= str_repeat($data[($i + 1)], (257 - $byte));
|
|
// move to next block
|
|
$i += 2;
|
|
}
|
|
}
|
|
return $decoded;
|
|
}
|
|
|
|
/**
|
|
* CCITTFaxDecode (NOT IMPLEMETED - RETURN AN EXCEPTION)
|
|
* Decompresses data encoded using the CCITT facsimile standard, reproducing the original data (typically monochrome image data at 1 bit per pixel).
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterCCITTFaxDecode($data) {
|
|
self::Error('~decodeFilterCCITTFaxDecode: this method has not been yet implemented');
|
|
//return $data;
|
|
}
|
|
|
|
/**
|
|
* JBIG2Decode (NOT IMPLEMETED - RETURN AN EXCEPTION)
|
|
* Decompresses data encoded using the JBIG2 standard, reproducing the original monochrome (1 bit per pixel) image data (or an approximation of that data).
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterJBIG2Decode($data) {
|
|
self::Error('~decodeFilterJBIG2Decode: this method has not been yet implemented');
|
|
//return $data;
|
|
}
|
|
|
|
/**
|
|
* DCTDecode (NOT IMPLEMETED - RETURN AN EXCEPTION)
|
|
* Decompresses data encoded using a DCT (discrete cosine transform) technique based on the JPEG standard, reproducing image sample data that approximates the original data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterDCTDecode($data) {
|
|
self::Error('~decodeFilterDCTDecode: this method has not been yet implemented');
|
|
//return $data;
|
|
}
|
|
|
|
/**
|
|
* JPXDecode (NOT IMPLEMETED - RETURN AN EXCEPTION)
|
|
* Decompresses data encoded using the wavelet-based JPEG2000 standard, reproducing the original image data.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterJPXDecode($data) {
|
|
self::Error('~decodeFilterJPXDecode: this method has not been yet implemented');
|
|
//return $data;
|
|
}
|
|
|
|
/**
|
|
* Crypt (NOT IMPLEMETED - RETURN AN EXCEPTION)
|
|
* Decrypts data encrypted by a security handler, reproducing the data as it was before encryption.
|
|
* @param string $data Data to decode.
|
|
* @return string Decoded data string.
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function decodeFilterCrypt($data) {
|
|
self::Error('~decodeFilterCrypt: this method has not been yet implemented');
|
|
//return $data;
|
|
}
|
|
|
|
// --- END FILTERS SECTION -------------------------------------------------
|
|
|
|
/**
|
|
* Throw an exception.
|
|
* @param string $msg The error message
|
|
* @since 1.0.000 (2011-05-23)
|
|
* @public static
|
|
*/
|
|
public static function Error($msg) {
|
|
throw new Exception('TCPDF_PARSER ERROR: '.$msg);
|
|
}
|
|
|
|
} // END OF TCPDF_FILTERS CLASS
|
|
|
|
//============================================================+
|
|
// END OF FILE
|
|
//============================================================+
|