<?php
//============================================================+
// File name   : tcpdf_parser.php
// Version     : 1.0.014
// Begin       : 2011-05-23
// Last Update : 2014-02-18
// Author      : Nicola Asuni - Tecnick.com LTD - www.tecnick.com - info@tecnick.com
// License     : http://www.tecnick.com/pagefiles/tcpdf/LICENSE.TXT GNU-LGPLv3
// -------------------------------------------------------------------
// Copyright (C) 2011-2014 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 parsing PDF documents.
//
//============================================================+

/**
 * @file
 * This is a PHP class for parsing PDF documents.<br>
 * @package com.tecnick.tcpdf
 * @author Nicola Asuni
 * @version 1.0.014
 */

// include class for decoding filters
require_once(dirname(__FILE__) . '/include/tcpdf_filters.php');

/**
 * @class TCPDF_PARSER
 * This is a PHP class for parsing PDF documents.<br>
 * @package com.tecnick.tcpdf
 * @brief This is a PHP class for parsing PDF documents..
 * @version 1.0.010
 * @author Nicola Asuni - info@tecnick.com
 */
class TCPDF_PARSER
{

    /**
     * Raw content of the PDF document.
     * @private
     */
    private $pdfdata = '';

    /**
     * XREF data.
     * @protected
     */
    protected $xref = array();

    /**
     * Array of PDF objects.
     * @protected
     */
    protected $objects = array();

    /**
     * Class object for decoding filters.
     * @private
     */
    private $FilterDecoders;

    /**
     * Array of configuration parameters.
     * @private
     */
    private $cfg = array(
        'die_for_errors' => false,
        'ignore_filter_decoding_errors' => true,
        'ignore_missing_filter_decoders' => true,
    );

// -----------------------------------------------------------------------------

    /**
     * Parse a PDF document an return an array of objects.
     * @param $data (string) PDF data to parse.
     * @param $cfg (array) Array of configuration parameters:
     *            'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
     *            'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
     *            'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
     * @public
     * @since 1.0.000 (2011-05-24)
     */
    public function __construct($data, $cfg = array())
    {
        if (empty($data)) {
            $this->Error('Empty PDF data.');
        }
        // find the pdf header starting position
        if (($trimpos = strpos($data, '%PDF-')) === FALSE) {
            $this->Error('Invalid PDF data: missing %PDF header.');
        }
        // get PDF content string
        $this->pdfdata = substr($data, $trimpos);
        // get length
        $pdflen = strlen($this->pdfdata);
        // set configuration parameters
        $this->setConfig($cfg);
        // get xref and trailer data
        $this->xref = $this->getXrefData();
        // parse all document objects
        $this->objects = array();
        foreach ($this->xref['xref'] as $obj => $offset) {
            if (!isset($this->objects[$obj]) AND ($offset > 0)) {
                // decode objects with positive offset
                $this->objects[$obj] = $this->getIndirectObject($obj, $offset, true);
            }
        }
        // release some memory
        unset($this->pdfdata);
        $this->pdfdata = '';
    }

    /**
     * Set the configuration parameters.
     * @param $cfg (array) Array of configuration parameters:
     *            'die_for_errors' : if true termitate the program execution in case of error, otherwise thows an exception;
     *            'ignore_filter_decoding_errors' : if true ignore filter decoding errors;
     *            'ignore_missing_filter_decoders' : if true ignore missing filter decoding errors.
     * @public
     */
    protected function setConfig($cfg)
    {
        if (isset($cfg['die_for_errors'])) {
            $this->cfg['die_for_errors'] = !!$cfg['die_for_errors'];
        }
        if (isset($cfg['ignore_filter_decoding_errors'])) {
            $this->cfg['ignore_filter_decoding_errors'] = !!$cfg['ignore_filter_decoding_errors'];
        }
        if (isset($cfg['ignore_missing_filter_decoders'])) {
            $this->cfg['ignore_missing_filter_decoders'] = !!$cfg['ignore_missing_filter_decoders'];
        }
    }

    /**
     * Return an array of parsed PDF document objects.
     * @return (array) Array of parsed PDF document objects.
     * @public
     * @since 1.0.000 (2011-06-26)
     */
    public function getParsedData()
    {
        return array($this->xref, $this->objects);
    }

    /**
     * Get Cross-Reference (xref) table and trailer data from PDF document data.
     * @param $offset (int) xref offset (if know).
     * @param $xref (array) previous xref array (if any).
     * @return Array containing xref and trailer data.
     * @protected
     * @since 1.0.000 (2011-05-24)
     */
    protected function getXrefData($offset = 0, $xref = array())
    {
        if ($offset == 0) {
            // find last startxref
            if (preg_match_all('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_SET_ORDER, $offset) == 0) {
                $this->Error('Unable to find startxref');
            }
            $matches = array_pop($matches);
            $startxref = $matches[1];
        } elseif (strpos($this->pdfdata, 'xref', $offset) == $offset) {
            // Already pointing at the xref table
            $startxref = $offset;
        } elseif (preg_match('/([0-9]+[\s][0-9]+[\s]obj)/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
            // Cross-Reference Stream object
            $startxref = $offset;
        } elseif (preg_match('/[\r\n]startxref[\s]*[\r\n]+([0-9]+)[\s]*[\r\n]+%%EOF/i', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset)) {
            // startxref found
            $startxref = $matches[1][0];
        } else {
            $this->Error('Unable to find startxref');
        }
        // check xref position
        if (strpos($this->pdfdata, 'xref', $startxref) == $startxref) {
            // Cross-Reference
            $xref = $this->decodeXref($startxref, $xref);
        } else {
            // Cross-Reference Stream
            $xref = $this->decodeXrefStream($startxref, $xref);
        }
        if (empty($xref)) {
            $this->Error('Unable to find xref');
        }
        return $xref;
    }

    /**
     * Decode the Cross-Reference section
     * @param $startxref (int) Offset at which the xref section starts (position of the 'xref' keyword).
     * @param $xref (array) Previous xref array (if any).
     * @return Array containing xref and trailer data.
     * @protected
     * @since 1.0.000 (2011-06-20)
     */
    protected function decodeXref($startxref, $xref = array())
    {
        $startxref += 4; // 4 is the lenght of the word 'xref'
        // skip initial white space chars: \x00 null (NUL), \x09 horizontal tab (HT), \x0A line feed (LF), \x0C form feed (FF), \x0D carriage return (CR), \x20 space (SP)
        $offset = $startxref + strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $startxref);
        // initialize object number
        $obj_num = 0;
        // search for cross-reference entries or subsection
        while (preg_match('/([0-9]+)[\x20]([0-9]+)[\x20]?([nf]?)(\r\n|[\x20]?[\r\n])/', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
            if ($matches[0][1] != $offset) {
                // we are on another section
                break;
            }
            $offset += strlen($matches[0][0]);
            if ($matches[3][0] == 'n') {
                // create unique object index: [object number]_[generation number]
                $index = $obj_num . '_' . intval($matches[2][0]);
                // check if object already exist
                if (!isset($xref['xref'][$index])) {
                    // store object offset position
                    $xref['xref'][$index] = intval($matches[1][0]);
                }
                ++$obj_num;
            } elseif ($matches[3][0] == 'f') {
                ++$obj_num;
            } else {
                // object number (index)
                $obj_num = intval($matches[1][0]);
            }
        }
        // get trailer data
        if (preg_match('/trailer[\s]*<<(.*)>>/isU', $this->pdfdata, $matches, PREG_OFFSET_CAPTURE, $offset) > 0) {
            $trailer_data = $matches[1][0];
            if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
                // get only the last updated version
                $xref['trailer'] = array();
                // parse trailer_data
                if (preg_match('/Size[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
                    $xref['trailer']['size'] = intval($matches[1]);
                }
                if (preg_match('/Root[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
                    $xref['trailer']['root'] = intval($matches[1]) . '_' . intval($matches[2]);
                }
                if (preg_match('/Encrypt[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
                    $xref['trailer']['encrypt'] = intval($matches[1]) . '_' . intval($matches[2]);
                }
                if (preg_match('/Info[\s]+([0-9]+)[\s]+([0-9]+)[\s]+R/i', $trailer_data, $matches) > 0) {
                    $xref['trailer']['info'] = intval($matches[1]) . '_' . intval($matches[2]);
                }
                if (preg_match('/ID[\s]*[\[][\s]*[<]([^>]*)[>][\s]*[<]([^>]*)[>]/i', $trailer_data, $matches) > 0) {
                    $xref['trailer']['id'] = array();
                    $xref['trailer']['id'][0] = $matches[1];
                    $xref['trailer']['id'][1] = $matches[2];
                }
            }
            if (preg_match('/Prev[\s]+([0-9]+)/i', $trailer_data, $matches) > 0) {
                // get previous xref
                $xref = $this->getXrefData(intval($matches[1]), $xref);
            }
        } else {
            $this->Error('Unable to find trailer');
        }
        return $xref;
    }

    /**
     * Decode the Cross-Reference Stream section
     * @param $startxref (int) Offset at which the xref section starts.
     * @param $xref (array) Previous xref array (if any).
     * @return Array containing xref and trailer data.
     * @protected
     * @since 1.0.003 (2013-03-16)
     */
    protected function decodeXrefStream($startxref, $xref = array())
    {
        // try to read Cross-Reference Stream
        $xrefobj = $this->getRawObject($startxref);
        $xrefcrs = $this->getIndirectObject($xrefobj[1], $startxref, true);
        if (!isset($xref['trailer']) OR empty($xref['trailer'])) {
            // get only the last updated version
            $xref['trailer'] = array();
            $filltrailer = true;
        } else {
            $filltrailer = false;
        }
        if (!isset($xref['xref'])) {
            $xref['xref'] = array();
        }
        $valid_crs = false;
        $columns = 0;
        $sarr = $xrefcrs[0][1];
        foreach ($sarr as $k => $v) {
            if (($v[0] == '/') AND ($v[1] == 'Type') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == '/') AND ($sarr[($k + 1)][1] == 'XRef'))) {
                $valid_crs = true;
            } elseif (($v[0] == '/') AND ($v[1] == 'Index') AND (isset($sarr[($k + 1)]))) {
                // first object number in the subsection
                $index_first = intval($sarr[($k + 1)][1][0][1]);
                // number of entries in the subsection
                $index_entries = intval($sarr[($k + 1)][1][1][1]);
            } elseif (($v[0] == '/') AND ($v[1] == 'Prev') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == 'numeric'))) {
                // get previous xref offset
                $prevxref = intval($sarr[($k + 1)][1]);
            } elseif (($v[0] == '/') AND ($v[1] == 'W') AND (isset($sarr[($k + 1)]))) {
                // number of bytes (in the decoded stream) of the corresponding field
                $wb = array();
                $wb[0] = intval($sarr[($k + 1)][1][0][1]);
                $wb[1] = intval($sarr[($k + 1)][1][1][1]);
                $wb[2] = intval($sarr[($k + 1)][1][2][1]);
            } elseif (($v[0] == '/') AND ($v[1] == 'DecodeParms') AND (isset($sarr[($k + 1)][1]))) {
                $decpar = $sarr[($k + 1)][1];
                foreach ($decpar as $kdc => $vdc) {
                    if (($vdc[0] == '/') AND ($vdc[1] == 'Columns') AND (isset($decpar[($kdc + 1)]) AND ($decpar[($kdc + 1)][0] == 'numeric'))) {
                        $columns = intval($decpar[($kdc + 1)][1]);
                    } elseif (($vdc[0] == '/') AND ($vdc[1] == 'Predictor') AND (isset($decpar[($kdc + 1)]) AND ($decpar[($kdc + 1)][0] == 'numeric'))) {
                        $predictor = intval($decpar[($kdc + 1)][1]);
                    }
                }
            } elseif ($filltrailer) {
                if (($v[0] == '/') AND ($v[1] == 'Size') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == 'numeric'))) {
                    $xref['trailer']['size'] = $sarr[($k + 1)][1];
                } elseif (($v[0] == '/') AND ($v[1] == 'Root') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == 'objref'))) {
                    $xref['trailer']['root'] = $sarr[($k + 1)][1];
                } elseif (($v[0] == '/') AND ($v[1] == 'Info') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == 'objref'))) {
                    $xref['trailer']['info'] = $sarr[($k + 1)][1];
                } elseif (($v[0] == '/') AND ($v[1] == 'Encrypt') AND (isset($sarr[($k + 1)]) AND ($sarr[($k + 1)][0] == 'objref'))) {
                    $xref['trailer']['encrypt'] = $sarr[($k + 1)][1];
                } elseif (($v[0] == '/') AND ($v[1] == 'ID') AND (isset($sarr[($k + 1)]))) {
                    $xref['trailer']['id'] = array();
                    $xref['trailer']['id'][0] = $sarr[($k + 1)][1][0][1];
                    $xref['trailer']['id'][1] = $sarr[($k + 1)][1][1][1];
                }
            }
        }
        // decode data
        if ($valid_crs AND isset($xrefcrs[1][3][0])) {
            // number of bytes in a row
            $rowlen = ($columns + 1);
            // convert the stream into an array of integers
            $sdata = unpack('C*', $xrefcrs[1][3][0]);
            // split the rows
            $sdata = array_chunk($sdata, $rowlen);
            // initialize decoded array
            $ddata = array();
            // initialize first row with zeros
            $prev_row = array_fill(0, $rowlen, 0);
            // for each row apply PNG unpredictor
            foreach ($sdata as $k => $row) {
                // initialize new row
                $ddata[$k] = array();
                // get PNG predictor value
                $predictor = (10 + $row[0]);
                // for each byte on the row
                for ($i = 1; $i <= $columns; ++$i) {
                    // new index
                    $j = ($i - 1);
                    $row_up = $prev_row[$j];
                    if ($i == 1) {
                        $row_left = 0;
                        $row_upleft = 0;
                    } else {
                        $row_left = $row[($i - 1)];
                        $row_upleft = $prev_row[($j - 1)];
                    }
                    switch ($predictor) {
                        case 10:
                        { // PNG prediction (on encoding, PNG None on all rows)
                            $ddata[$k][$j] = $row[$i];
                            break;
                        }
                        case 11:
                        { // PNG prediction (on encoding, PNG Sub on all rows)
                            $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
                            break;
                        }
                        case 12:
                        { // PNG prediction (on encoding, PNG Up on all rows)
                            $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
                            break;
                        }
                        case 13:
                        { // PNG prediction (on encoding, PNG Average on all rows)
                            $ddata[$k][$j] = (($row[$i] + (($row_left + $row_up) / 2)) & 0xff);
                            break;
                        }
                        case 14:
                        { // PNG prediction (on encoding, PNG Paeth on all rows)
                            // initial estimate
                            $p = ($row_left + $row_up - $row_upleft);
                            // distances
                            $pa = abs($p - $row_left);
                            $pb = abs($p - $row_up);
                            $pc = abs($p - $row_upleft);
                            $pmin = min($pa, $pb, $pc);
                            // return minumum distance
                            switch ($pmin) {
                                case $pa:
                                {
                                    $ddata[$k][$j] = (($row[$i] + $row_left) & 0xff);
                                    break;
                                }
                                case $pb:
                                {
                                    $ddata[$k][$j] = (($row[$i] + $row_up) & 0xff);
                                    break;
                                }
                                case $pc:
                                {
                                    $ddata[$k][$j] = (($row[$i] + $row_upleft) & 0xff);
                                    break;
                                }
                            }
                            break;
                        }
                        default:
                            { // PNG prediction (on encoding, PNG optimum)
                            $this->Error('Unknown PNG predictor');
                            break;
                            }
                    }
                }
                $prev_row = $ddata[$k];
            } // end for each row
            // complete decoding
            $sdata = array();
            // for every row
            foreach ($ddata as $k => $row) {
                // initialize new row
                $sdata[$k] = array(0, 0, 0);
                if ($wb[0] == 0) {
                    // default type field
                    $sdata[$k][0] = 1;
                }
                $i = 0; // count bytes in the row
                // for every column
                for ($c = 0; $c < 3; ++$c) {
                    // for every byte on the column
                    for ($b = 0; $b < $wb[$c]; ++$b) {
                        if (isset($row[$i])) {
                            $sdata[$k][$c] += ($row[$i] << (($wb[$c] - 1 - $b) * 8));
                        }
                        ++$i;
                    }
                }
            }
            $ddata = array();
            // fill xref
            if (isset($index_first)) {
                $obj_num = $index_first;
            } else {
                $obj_num = 0;
            }
            foreach ($sdata as $k => $row) {
                switch ($row[0]) {
                    case 0:
                    { // (f) linked list of free objects
                        break;
                    }
                    case 1:
                    { // (n) objects that are in use but are not compressed
                        // create unique object index: [object number]_[generation number]
                        $index = $obj_num . '_' . $row[2];
                        // check if object already exist
                        if (!isset($xref['xref'][$index])) {
                            // store object offset position
                            $xref['xref'][$index] = $row[1];
                        }
                        break;
                    }
                    case 2:
                    { // compressed objects
                        // $row[1] = object number of the object stream in which this object is stored
                        // $row[2] = index of this object within the object stream
                        $index = $row[1] . '_0_' . $row[2];
                        $xref['xref'][$index] = -1;
                        break;
                    }
                    default:
                        { // null objects
                        break;
                        }
                }
                ++$obj_num;
            }
        } // end decoding data
        if (isset($prevxref)) {
            // get previous xref
            $xref = $this->getXrefData($prevxref, $xref);
        }
        return $xref;
    }

    /**
     * Get object type, raw value and offset to next object
     * @param $offset (int) Object offset.
     * @return array containing object type, raw value and offset to next object
     * @protected
     * @since 1.0.000 (2011-06-20)
     */
    protected function getRawObject($offset = 0)
    {
        $objtype = ''; // object type to be returned
        $objval = ''; // object value to be returned
        // skip initial white space chars: \x00 null (NUL), \x09 horizontal tab (HT), \x0A line feed (LF), \x0C form feed (FF), \x0D carriage return (CR), \x20 space (SP)
        $offset += strspn($this->pdfdata, "\x00\x09\x0a\x0c\x0d\x20", $offset);
        // get first char
        $char = $this->pdfdata[$offset];
        // get object type
        switch ($char) {
            case '%':
            { // \x25 PERCENT SIGN
                // skip comment and search for next token
                $next = strcspn($this->pdfdata, "\r\n", $offset);
                if ($next > 0) {
                    $offset += $next;
                    return $this->getRawObject($offset);
                }
                break;
            }
            case '/':
            { // \x2F SOLIDUS
                // name object
                $objtype = $char;
                ++$offset;
                if (preg_match('/^([^\x00\x09\x0a\x0c\x0d\x20\s\x28\x29\x3c\x3e\x5b\x5d\x7b\x7d\x2f\x25]+)/', substr($this->pdfdata, $offset, 256), $matches) == 1) {
                    $objval = $matches[1]; // unescaped value
                    $offset += strlen($objval);
                }
                break;
            }
            case '(': // \x28 LEFT PARENTHESIS
            case ')':
            { // \x29 RIGHT PARENTHESIS
                // literal string object
                $objtype = $char;
                ++$offset;
                $strpos = $offset;
                if ($char == '(') {
                    $open_bracket = 1;
                    while ($open_bracket > 0) {
                        if (!isset($this->pdfdata{$strpos})) {
                            break;
                        }
                        $ch = $this->pdfdata{$strpos};
                        switch ($ch) {
                            case '\\':
                            { // REVERSE SOLIDUS (5Ch) (Backslash)
                                // skip next character
                                ++$strpos;
                                break;
                            }
                            case '(':
                            { // LEFT PARENHESIS (28h)
                                ++$open_bracket;
                                break;
                            }
                            case ')':
                            { // RIGHT PARENTHESIS (29h)
                                --$open_bracket;
                                break;
                            }
                        }
                        ++$strpos;
                    }
                    $objval = substr($this->pdfdata, $offset, ($strpos - $offset - 1));
                    $offset = $strpos;
                }
                break;
            }
            case '[': // \x5B LEFT SQUARE BRACKET
            case ']':
            { // \x5D RIGHT SQUARE BRACKET
                // array object
                $objtype = $char;
                ++$offset;
                if ($char == '[') {
                    // get array content
                    $objval = array();
                    do {
                        // get element
                        $element = $this->getRawObject($offset);
                        $offset = $element[2];
                        $objval[] = $element;
                    } while ($element[0] != ']');
                    // remove closing delimiter
                    array_pop($objval);
                }
                break;
            }
            case '<': // \x3C LESS-THAN SIGN
            case '>':
            { // \x3E GREATER-THAN SIGN
                if (isset($this->pdfdata{($offset + 1)}) AND ($this->pdfdata{($offset + 1)} == $char)) {
                    // dictionary object
                    $objtype = $char . $char;
                    $offset += 2;
                    if ($char == '<') {
                        // get array content
                        $objval = array();
                        do {
                            // get element
                            $element = $this->getRawObject($offset);
                            $offset = $element[2];
                            $objval[] = $element;
                        } while ($element[0] != '>>');
                        // remove closing delimiter
                        array_pop($objval);
                    }
                } else {
                    // hexadecimal string object
                    $objtype = $char;
                    ++$offset;
                    if (($char == '<') AND (preg_match('/^([0-9A-Fa-f\x09\x0a\x0c\x0d\x20]+)>/iU', substr($this->pdfdata, $offset), $matches) == 1)) {
                        // remove white space characters
                        $objval = strtr($matches[1], "\x09\x0a\x0c\x0d\x20", '');
                        $offset += strlen($matches[0]);
                    } elseif (($endpos = strpos($this->pdfdata, '>', $offset)) !== FALSE) {
                        $offset = $endpos + 1;
                    }
                }
                break;
            }
            default:
                {
                if (substr($this->pdfdata, $offset, 6) == 'endobj') {
                    // indirect object
                    $objtype = 'endobj';
                    $offset += 6;
                } elseif (substr($this->pdfdata, $offset, 4) == 'null') {
                    // null object
                    $objtype = 'null';
                    $offset += 4;
                    $objval = 'null';
                } elseif (substr($this->pdfdata, $offset, 4) == 'true') {
                    // boolean true object
                    $objtype = 'boolean';
                    $offset += 4;
                    $objval = 'true';
                } elseif (substr($this->pdfdata, $offset, 5) == 'false') {
                    // boolean false object
                    $objtype = 'boolean';
                    $offset += 5;
                    $objval = 'false';
                } elseif (substr($this->pdfdata, $offset, 6) == 'stream') {
                    // start stream object
                    $objtype = 'stream';
                    $offset += 6;
                    if (preg_match('/^([\r]?[\n])/isU', substr($this->pdfdata, $offset), $matches) == 1) {
                        $offset += strlen($matches[0]);
                        if (preg_match('/(endstream)[\x09\x0a\x0c\x0d\x20]/isU', substr($this->pdfdata, $offset), $matches, PREG_OFFSET_CAPTURE) == 1) {
                            $objval = substr($this->pdfdata, $offset, $matches[0][1]);
                            $offset += $matches[1][1];
                        }
                    }
                } elseif (substr($this->pdfdata, $offset, 9) == 'endstream') {
                    // end stream object
                    $objtype = 'endstream';
                    $offset += 9;
                } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+R/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
                    // indirect object reference
                    $objtype = 'objref';
                    $offset += strlen($matches[0]);
                    $objval = intval($matches[1]) . '_' . intval($matches[2]);
                } elseif (preg_match('/^([0-9]+)[\s]+([0-9]+)[\s]+obj/iU', substr($this->pdfdata, $offset, 33), $matches) == 1) {
                    // object start
                    $objtype = 'obj';
                    $objval = intval($matches[1]) . '_' . intval($matches[2]);
                    $offset += strlen($matches[0]);
                } elseif (($numlen = strspn($this->pdfdata, '+-.0123456789', $offset)) > 0) {
                    // numeric object
                    $objtype = 'numeric';
                    $objval = substr($this->pdfdata, $offset, $numlen);
                    $offset += $numlen;
                }
                break;
                }
        }
        return array($objtype, $objval, $offset);
    }

    /**
     * Get content of indirect object.
     * @param $obj_ref (string) Object number and generation number separated by underscore character.
     * @param $offset (int) Object offset.
     * @param $decoding (boolean) If true decode streams.
     * @return array containing object data.
     * @protected
     * @since 1.0.000 (2011-05-24)
     */
    protected function getIndirectObject($obj_ref, $offset = 0, $decoding = true)
    {
        $obj = explode('_', $obj_ref);
        if (($obj === false) OR (count($obj) != 2)) {
            $this->Error('Invalid object reference: ' . $obj);
            return;
        }
        $objref = $obj[0] . ' ' . $obj[1] . ' obj';
        // ignore leading zeros
        $offset += strspn($this->pdfdata, '0', $offset);
        if (strpos($this->pdfdata, $objref, $offset) != $offset) {
            // an indirect reference to an undefined object shall be considered a reference to the null object
            return array('null', 'null', $offset);
        }
        // starting position of object content
        $offset += strlen($objref);
        // get array of object content
        $objdata = array();
        $i = 0; // object main index
        do {
            // get element
            $element = $this->getRawObject($offset);
            $offset = $element[2];
            // decode stream using stream's dictionary information
            if ($decoding AND ($element[0] == 'stream') AND (isset($objdata[($i - 1)][0])) AND ($objdata[($i - 1)][0] == '<<')) {
                $element[3] = $this->decodeStream($objdata[($i - 1)][1], $element[1]);
            }
            $objdata[$i] = $element;
            ++$i;
        } while ($element[0] != 'endobj');
        // remove closing delimiter
        array_pop($objdata);
        // return raw object content
        return $objdata;
    }

    /**
     * Get the content of object, resolving indect object reference if necessary.
     * @param $obj (string) Object value.
     * @return array containing object data.
     * @protected
     * @since 1.0.000 (2011-06-26)
     */
    protected function getObjectVal($obj)
    {
        if ($obj[0] == 'objref') {
            // reference to indirect object
            if (isset($this->objects[$obj[1]])) {
                // this object has been already parsed
                return $this->objects[$obj[1]];
            } elseif (isset($this->xref[$obj[1]])) {
                // parse new object
                $this->objects[$obj[1]] = $this->getIndirectObject($obj[1], $this->xref[$obj[1]], false);
                return $this->objects[$obj[1]];
            }
        }
        return $obj;
    }

    /**
     * Decode the specified stream.
     * @param $sdic (array) Stream's dictionary array.
     * @param $stream (string) Stream to decode.
     * @return array containing decoded stream data and remaining filters.
     * @protected
     * @since 1.0.000 (2011-06-22)
     */
    protected function decodeStream($sdic, $stream)
    {
        // get stream lenght and filters
        $slength = strlen($stream);
        if ($slength <= 0) {
            return array('', array());
        }
        $filters = array();
        foreach ($sdic as $k => $v) {
            if ($v[0] == '/') {
                if (($v[1] == 'Length') AND (isset($sdic[($k + 1)])) AND ($sdic[($k + 1)][0] == 'numeric')) {
                    // get declared stream lenght
                    $declength = intval($sdic[($k + 1)][1]);
                    if ($declength < $slength) {
                        $stream = substr($stream, 0, $declength);
                        $slength = $declength;
                    }
                } elseif (($v[1] == 'Filter') AND (isset($sdic[($k + 1)]))) {
                    // resolve indirect object
                    $objval = $this->getObjectVal($sdic[($k + 1)]);
                    if ($objval[0] == '/') {
                        // single filter
                        $filters[] = $objval[1];
                    } elseif ($objval[0] == '[') {
                        // array of filters
                        foreach ($objval[1] as $flt) {
                            if ($flt[0] == '/') {
                                $filters[] = $flt[1];
                            }
                        }
                    }
                }
            }
        }
        // decode the stream
        $remaining_filters = array();
        foreach ($filters as $filter) {
            if (in_array($filter, TCPDF_FILTERS::getAvailableFilters())) {
                try {
                    $stream = TCPDF_FILTERS::decodeFilter($filter, $stream);
                } catch (Exception $e) {
                    $emsg = $e->getMessage();
                    if ((($emsg[0] == '~') AND !$this->cfg['ignore_missing_filter_decoders'])
                        OR (($emsg[0] != '~') AND !$this->cfg['ignore_filter_decoding_errors'])
                    ) {
                        $this->Error($e->getMessage());
                    }
                }
            } else {
                // add missing filter to array
                $remaining_filters[] = $filter;
            }
        }
        return array($stream, $remaining_filters);
    }

    /**
     * Throw an exception or print an error message and die if the K_TCPDF_PARSER_THROW_EXCEPTION_ERROR constant is set to true.
     * @param $msg (string) The error message
     * @public
     * @since 1.0.000 (2011-05-23)
     */
    public function Error($msg)
    {
        if ($this->cfg['die_for_errors']) {
            die('<strong>TCPDF_PARSER ERROR: </strong>' . $msg);
        } else {
            throw new Exception('TCPDF_PARSER ERROR: ' . $msg);
        }
    }

} // END OF TCPDF_PARSER CLASS

//============================================================+
// END OF FILE
//============================================================+
