<?php
/**
 * Exifer
 * Extracts EXIF information from digital photos.
 *
 * Copyright © 2003 Jake Olefsky
 * http://www.offsky.com/software/exif/index.php
 * jake@olefsky.com
 *
 * Please see exif.php for the complete information about this software.
 *
 * This program is free software; you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details. http://www.gnu.org/copyleft/gpl.html
 */

/**
 * Looks up the name of the tag for the MakerNote (Depends on Manufacturer)
 *
 * @param type $tag
 * @return string
 */
function lookup_Olympus_tag($tag) {
	switch($tag) {
		case "0200": $tag = "SpecialMode";break;
		case "0201": $tag = "JpegQual";break;
		case "0202": $tag = "Macro";break;
		case "0203": $tag = "Unknown1";break;
		case "0204": $tag = "DigiZoom";break;
		case "0205": $tag = "Unknown2";break;
		case "0206": $tag = "Unknown3";break;
		case "0207": $tag = "SoftwareRelease";break;
		case "0208": $tag = "PictInfo";break;
		case "0209": $tag = "CameraID";break;
		case "0f00": $tag = "DataDump";break;

		default: $tag = "unknown:".$tag;break;
	}

	return $tag;
}

/**
 * Formats Data for the data type
 *
 * @param type $type
 * @param type $tag
 * @param type $intel
 * @param type $data
 * @return type
 */
function formatOlympusData($type,$tag,$intel,$data) {
	if($type=="ASCII") {

	} else if($type=="URATIONAL" || $type=="SRATIONAL") {
		$data = unRational($data,$type,$intel);
		if($intel==1) $data = intel2Moto($data);

		if($tag=="0204") { //DigitalZoom
			$data=$data."x";
		}
		if($tag=="0205") { //Unknown2

		}
	} else if($type=="USHORT" || $type=="SSHORT" || $type=="ULONG" || $type=="SLONG" || $type=="FLOAT" || $type=="DOUBLE") {
		$data = rational($data,$type,$intel);

		if($tag=="0201") { //JPEGQuality
			if($data == 1) $data = "SQ";
			else if($data == 2) $data = "HQ";
			else if($data == 3) $data = "SHQ";
			else $data = gettext("Unknown").": ".$data;
		}
		if($tag=="0202") { //Macro
			if($data == 0) $data = "Normal";
			else if($data == 1) $data = "Macro";
			else $data = gettext("Unknown").": ".$data;
		}
	} else if($type=="UNDEFINED") {

	} else {
		$data = bin2hex($data);
		if($intel==1) $data = intel2Moto($data);
	}

	return $data;
}

/**
 * Olympus Special data section
// - Updated by Zenphoto for new header tag in E-410/E-510/E-3 cameras. 2/24/2008
 *
 * @param type $block
 * @param type $result
 * @param type $seek
 * @param type $globalOffset
 * @return boolean
 */
function parseOlympus($block, &$result, $seek, $globalOffset) {

	if($result['Endien']=="Intel") $intel = 1;
	else $intel = 0;

	$model = $result['IFD0']['Model'];

	// New header for new DSLRs - Check for it because the
	// number of bytes that count the IFD fields differ in each case.
	// Fixed by Zenphoto 2/24/08
	$new = false;
	if (substr($block, 0, 8) == "OLYMPUS\x00") {
		$new = true;
	} else if (substr($block, 0, 7) == "OLYMP\x00\x01"
		|| substr($block, 0, 7) == "OLYMP\x00\x02") {
		$new = false;
	} else {
		// Header does not match known Olympus headers.
		// This is not a valid OLYMPUS Makernote.
		return false;
	}

	// Offset of IFD entry after Olympus header.
	$place = 8;
	$offset = 8;

	// Get number of tags (1 or 2 bytes, depending on New or Old makernote)
	$countfieldbits = $new ? 1 : 2;
	// New makernote repeats 1-byte value twice, so increment $place by 2 in either case.
	$num = bin2hex(substr($block, $place, $countfieldbits)); $place += 2;
	if ($intel == 1) $num = intel2Moto($num);
	$ntags = hexdec($num);
	$result['SubIFD']['MakerNote']['MakerNoteNumTags'] = $ntags;

	//loop thru all tags  Each field is 12 bytes
	for($i=0; $i < $ntags; $i++) {
		//2 byte tag
		$tag = bin2hex(substr($block, $place,2));
		$place += 2;
		if ($intel == 1) $tag = intel2Moto($tag);
		$tag_name = lookup_Olympus_tag($tag);

		//2 byte type
		$type = bin2hex(substr($block, $place,2));
		$place += 2;
		if ($intel == 1) $type = intel2Moto($type);
		lookup_type($type,$size);

		//4 byte count of number of data units
		$count = bin2hex(substr($block, $place,4));
		$place+=4;
		if ($intel == 1) $count = intel2Moto($count);
		$bytesofdata = $size * hexdec($count);

		//4 byte value of data or pointer to data
		$value = substr($block, $place,4);
		$place += 4;


		if ($bytesofdata <= 4) {
			$data = substr($value,0,$bytesofdata);
		} else {
			$value = bin2hex($value);
			if($intel==1) $value = intel2Moto($value);
			$v = fseek($seek,$globalOffset+hexdec($value));  //offsets are from TIFF header which is 12 bytes from the start of the file
			if(isset($GLOBALS['exiferFileSize']) && $v == 0 && $bytesofdata < $GLOBALS['exiferFileSize']) {
				$data = fread($seek, $bytesofdata);
			} else {
				$result['Errors'] = $result['Errors']++;
				$data = '';
			}
		}
		$formated_data = formatOlympusData($type,$tag,$intel,$data);

		if($result['VerboseOutput']==1) {
			$result['SubIFD']['MakerNote'][$tag_name] = $formated_data;
			if($type=="URATIONAL" || $type=="SRATIONAL" || $type=="USHORT" || $type=="SSHORT" || $type=="ULONG" || $type=="SLONG" || $type=="FLOAT" || $type=="DOUBLE") {
				$data = bin2hex($data);
				if($intel==1) $data = intel2Moto($data);
			}
			$result['SubIFD']['MakerNote'][$tag_name."_Verbose"]['RawData'] = $data;
			$result['SubIFD']['MakerNote'][$tag_name."_Verbose"]['Type'] = $type;
			$result['SubIFD']['MakerNote'][$tag_name."_Verbose"]['Bytes'] = $bytesofdata;
		} else {
			$result['SubIFD']['MakerNote'][$tag_name] = $formated_data;
		}
	}
}