--- /dev/null
+<?php
+
+/**
+ * PEL: PHP Exif Library.
+ * A library with support for reading and
+ * writing all Exif headers in JPEG and TIFF images using PHP.
+ *
+ * Copyright (C) 2004, 2005, 2006, 2007 Martin Geisler.
+ *
+ * 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program in the file COPYING; if not, write to the
+ * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
+ * Boston, MA 02110-1301 USA
+ */
+namespace lsolesen\pel;
+
+/**
+ * Classes used to hold ASCII strings.
+ *
+ * The classes defined here are to be used for Exif entries holding
+ * ASCII strings, such as {@link PelTag::MAKE}, {@link
+ * PelTag::SOFTWARE}, and {@link PelTag::DATE_TIME}. For
+ * entries holding normal textual ASCII strings the class {@link
+ * PelEntryAscii} should be used, but for entries holding
+ * timestamps the class {@link PelEntryTime} would be more
+ * convenient instead. Copyright information is handled by the {@link
+ * PelEntryCopyright} class.
+ *
+ * @author Martin Geisler <mgeisler@users.sourceforge.net>
+ * @license http://www.gnu.org/licenses/gpl.html GNU General Public
+ * License (GPL)
+ * @package PEL
+ */
+
+/**
+ * Class for holding a date and time.
+ *
+ * This class can hold a timestamp, and it will be used as
+ * in this example where the time is advanced by one week:
+ * <code>
+ * $entry = $ifd->getEntry(PelTag::DATE_TIME_ORIGINAL);
+ * $time = $entry->getValue();
+ * print('The image was taken on the ' . date('jS', $time));
+ * $entry->setValue($time + 7 * 24 * 3600);
+ * </code>
+ *
+ * The example used a standard UNIX timestamp, which is the default
+ * for this class.
+ *
+ * But the Exif format defines dates outside the range of a UNIX
+ * timestamp (about 1970 to 2038) and so you can also get access to
+ * the timestamp in two other formats: a simple string or a Julian Day
+ * Count. Please see the Calendar extension in the PHP Manual for more
+ * information about the Julian Day Count.
+ *
+ * @author Martin Geisler <mgeisler@users.sourceforge.net>
+ * @package PEL
+ */
+class PelEntryTime extends PelEntryAscii
+{
+
+ /**
+ * Constant denoting a UNIX timestamp.
+ */
+ const UNIX_TIMESTAMP = 1;
+
+ /**
+ * Constant denoting a Exif string.
+ */
+ const EXIF_STRING = 2;
+
+ /**
+ * Constant denoting a Julian Day Count.
+ */
+ const JULIAN_DAY_COUNT = 3;
+
+ /**
+ * The Julian Day Count of the timestamp held by this entry.
+ *
+ * This is an integer counting the number of whole days since
+ * January 1st, 4713 B.C. The fractional part of the timestamp held
+ * by this entry is stored in {@link $seconds}.
+ *
+ * @var int
+ */
+ private $day_count;
+
+ /**
+ * The number of seconds into the day of the timestamp held by this
+ * entry.
+ *
+ * The number of whole days is stored in {@link $day_count} and the
+ * number of seconds left-over is stored here.
+ *
+ * @var int
+ */
+ private $seconds;
+
+ /**
+ * Make a new entry for holding a timestamp.
+ *
+ * @param integer $tag
+ * the Exif tag which this entry represents. There are
+ * only three standard tags which hold timestamp, so this should be
+ * one of the constants {@link PelTag::DATE_TIME}, {@link
+ * PelTag::DATE_TIME_ORIGINAL}, or {@link
+ * PelTag::DATE_TIME_DIGITIZED}.
+ *
+ * @param integer $timestamp
+ * the timestamp held by this entry in the correct form
+ * as indicated by the third argument. For {@link UNIX_TIMESTAMP}
+ * this is an integer counting the number of seconds since January
+ * 1st 1970, for {@link EXIF_STRING} this is a string of the form
+ * 'YYYY:MM:DD hh:mm:ss', and for {@link JULIAN_DAY_COUNT} this is a
+ * floating point number where the integer part denotes the day
+ * count and the fractional part denotes the time of day (0.25 means
+ * 6:00, 0.75 means 18:00).
+ *
+ * @param integer $type
+ * the type of the timestamp. This must be one of
+ * {@link UNIX_TIMESTAMP}, {@link EXIF_STRING}, or
+ * {@link JULIAN_DAY_COUNT}.
+ */
+ public function __construct($tag, $timestamp, $type = self::UNIX_TIMESTAMP)
+ {
+ parent::__construct($tag);
+ $this->setValue($timestamp, $type);
+ }
+
+ /**
+ * Return the timestamp of the entry.
+ *
+ * The timestamp held by this entry is returned in one of three
+ * formats: as a standard UNIX timestamp (default), as a fractional
+ * Julian Day Count, or as a string.
+ *
+ * @param integer $type
+ * the type of the timestamp. This must be one of
+ * {@link UNIX_TIMESTAMP}, {@link EXIF_STRING}, or
+ * {@link JULIAN_DAY_COUNT}.
+ *
+ * @return integer the timestamp held by this entry in the correct form
+ * as indicated by the type argument. For {@link UNIX_TIMESTAMP}
+ * this is an integer counting the number of seconds since January
+ * 1st 1970, for {@link EXIF_STRING} this is a string of the form
+ * 'YYYY:MM:DD hh:mm:ss', and for {@link JULIAN_DAY_COUNT} this is a
+ * floating point number where the integer part denotes the day
+ * count and the fractional part denotes the time of day (0.25 means
+ * 6:00, 0.75 means 18:00).
+ */
+ public function getValue($type = self::UNIX_TIMESTAMP)
+ {
+ switch ($type) {
+ case self::UNIX_TIMESTAMP:
+ $seconds = $this->convertJdToUnix($this->day_count);
+ if ($seconds === false) {
+ /*
+ * We get false if the Julian Day Count is outside the range
+ * of a UNIX timestamp.
+ */
+ return false;
+ } else {
+ return $seconds + $this->seconds;
+ }
+ break;
+ case self::EXIF_STRING:
+ list ($year, $month, $day) = $this->convertJdToGregorian($this->day_count);
+ $hours = (int) ($this->seconds / 3600);
+ $minutes = (int) ($this->seconds % 3600 / 60);
+ $seconds = $this->seconds % 60;
+ return sprintf('%04d:%02d:%02d %02d:%02d:%02d', $year, $month, $day, $hours, $minutes, $seconds);
+ case self::JULIAN_DAY_COUNT:
+ return $this->day_count + $this->seconds / 86400;
+ default:
+ throw new PelInvalidArgumentException(
+ 'Expected UNIX_TIMESTAMP (%d), ' . 'EXIF_STRING (%d), or ' . 'JULIAN_DAY_COUNT (%d) for $type, ' .
+ 'got %d.',
+ self::UNIX_TIMESTAMP,
+ self::EXIF_STRING,
+ self::JULIAN_DAY_COUNT,
+ $type);
+ }
+ }
+
+ /**
+ * Update the timestamp held by this entry.
+ *
+ * @param integer $timestamp
+ * the timestamp held by this entry in the correct form
+ * as indicated by the third argument. For {@link UNIX_TIMESTAMP}
+ * this is an integer counting the number of seconds since January
+ * 1st 1970, for {@link EXIF_STRING} this is a string of the form
+ * 'YYYY:MM:DD hh:mm:ss', and for {@link JULIAN_DAY_COUNT} this is a
+ * floating point number where the integer part denotes the day
+ * count and the fractional part denotes the time of day (0.25 means
+ * 6:00, 0.75 means 18:00).
+ *
+ * @param integer $type
+ * the type of the timestamp. This must be one of
+ * {@link UNIX_TIMESTAMP}, {@link EXIF_STRING}, or
+ * {@link JULIAN_DAY_COUNT}.
+ */
+ public function setValue($timestamp, $type = self::UNIX_TIMESTAMP)
+ {
+ switch ($type) {
+ case self::UNIX_TIMESTAMP:
+ $this->day_count = $this->convertUnixToJd($timestamp);
+ $this->seconds = $timestamp % 86400;
+ break;
+
+ case self::EXIF_STRING:
+ /* Clean the timestamp: some timestamps are broken other
+ * separators than ':' and ' '. */
+ $d = preg_split('/[^0-9]+/', $timestamp);
+ for ($i = 0; $i < 6; $i ++) {
+ if (empty($d[$i])) {
+ $d[$i] = 0;
+ }
+ }
+ $this->day_count = $this->convertGregorianToJd($d[0], $d[1], $d[2]);
+ $this->seconds = $d[3] * 3600 + $d[4] * 60 + $d[5];
+ break;
+
+ case self::JULIAN_DAY_COUNT:
+ $this->day_count = (int) floor($timestamp);
+ $this->seconds = (int) (86400 * ($timestamp - floor($timestamp)));
+ break;
+
+ default:
+ throw new PelInvalidArgumentException(
+ 'Expected UNIX_TIMESTAMP (%d), ' . 'EXIF_STRING (%d), or ' . 'JULIAN_DAY_COUNT (%d) for $type, ' .
+ 'got %d.',
+ self::UNIX_TIMESTAMP,
+ self::EXIF_STRING,
+ self::JULIAN_DAY_COUNT,
+ $type);
+ }
+
+ /*
+ * Now finally update the string which will be used when this is
+ * turned into bytes.
+ */
+ parent::setValue($this->getValue(self::EXIF_STRING));
+ }
+
+ // The following four functions are used for converting back and
+ // forth between the date formats. They are used in preference to
+ // the ones from the PHP calendar extension to avoid having to
+ // fiddle with timezones and to avoid depending on the extension.
+ //
+ // See http://www.hermetic.ch/cal_stud/jdn.htm#comp for a reference.
+
+ /**
+ * Converts a date in year/month/day format to a Julian Day count.
+ *
+ * @param integer $year
+ * the year.
+ * @param integer $month
+ * the month, 1 to 12.
+ * @param integer $day
+ * the day in the month.
+ * @return integer the Julian Day count.
+ */
+ public function convertGregorianToJd($year, $month, $day)
+ {
+ // Special case mapping 0/0/0 -> 0
+ if ($year == 0 || $month == 0 || $day == 0) {
+ return 0;
+ }
+
+ $m1412 = ($month <= 2) ? - 1 : 0;
+ return floor((1461 * ($year + 4800 + $m1412)) / 4) + floor((367 * ($month - 2 - 12 * $m1412)) / 12) -
+ floor((3 * floor(($year + 4900 + $m1412) / 100)) / 4) + $day - 32075;
+ }
+
+ /**
+ * Converts a Julian Day count to a year/month/day triple.
+ *
+ * @param
+ * int the Julian Day count.
+ * @return array an array with three entries: year, month, day.
+ */
+ public function convertJdToGregorian($jd)
+ {
+ // Special case mapping 0 -> 0/0/0
+ if ($jd == 0) {
+ return array(
+ 0,
+ 0,
+ 0
+ );
+ }
+
+ $l = $jd + 68569;
+ $n = floor((4 * $l) / 146097);
+ $l = $l - floor((146097 * $n + 3) / 4);
+ $i = floor((4000 * ($l + 1)) / 1461001);
+ $l = $l - floor((1461 * $i) / 4) + 31;
+ $j = floor((80 * $l) / 2447);
+ $d = $l - floor((2447 * $j) / 80);
+ $l = floor($j / 11);
+ $m = $j + 2 - (12 * $l);
+ $y = 100 * ($n - 49) + $i + $l;
+ return array(
+ $y,
+ $m,
+ $d
+ );
+ }
+
+ /**
+ * Converts a UNIX timestamp to a Julian Day count.
+ *
+ * @param integer $timestamp
+ * the timestamp.
+ * @return integer the Julian Day count.
+ */
+ public function convertUnixToJd($timestamp)
+ {
+ return (int) (floor($timestamp / 86400) + 2440588);
+ }
+
+ /**
+ * Converts a Julian Day count to a UNIX timestamp.
+ *
+ * @param integer $jd
+ * the Julian Day count.
+ *
+ * @return mixed $timestamp the integer timestamp or false if the
+ * day count cannot be represented as a UNIX timestamp.
+ */
+ public function convertJdToUnix($jd)
+ {
+ if ($jd > 0) {
+ $timestamp = ($jd - 2440588) * 86400;
+ if ($timestamp >= 0) {
+ return $timestamp;
+ }
+ }
+ return false;
+ }
+}
projects / yaffs-website / blobdiff