/**
* Make a new entry from a bunch of bytes.
*
* This method will create the proper subclass of {@link PelEntry}
* corresponding to the {@link PelTag} and {@link PelFormat} given.
* The entry will be initialized with the data given.
*
* Please note that the data you pass to this method should come
* from an image, that is, it should be raw bytes. If instead you
* want to create an entry for holding, say, an short integer, then
* create a {@link PelEntryShort} object directly and load the data
* into it.
*
* A {@link PelUnexpectedFormatException} is thrown if a mismatch is
* discovered between the tag and format, and likewise a {@link
* PelWrongComponentCountException} is thrown if the number of
* components does not match the requirements of the tag. The
* requirements for a given tag (if any) can be found in the
* documentation for {@link PelTag}.
*
* @param PelTag the tag of the entry.
*
* @param PelFormat the format of the entry.
*
* @param int the components in the entry.
*
* @param PelDataWindow the data which will be used to construct the
* entry.
*
* @return PelEntry a newly created entry, holding the data given.
*/
function newEntryFromData($tag, $format, $components, PelDataWindow $data)
{
/* First handle tags for which we have a specific PelEntryXXX
* class. */
switch ($this->type) {
case self::IFD0:
case self::IFD1:
case self::EXIF:
case self::INTEROPERABILITY:
switch ($tag) {
case PelTag::DATE_TIME:
case PelTag::DATE_TIME_ORIGINAL:
case PelTag::DATE_TIME_DIGITIZED:
if ($format != PelFormat::ASCII) {
throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::ASCII);
}
if ($components != 20) {
throw new PelWrongComponentCountException($this->type, $tag, $components, 20);
}
// TODO: handle timezones.
return new PelEntryTime($tag, $data->getBytes(0, -1), PelEntryTime::EXIF_STRING);
case PelTag::COPYRIGHT:
if ($format != PelFormat::ASCII) {
throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::ASCII);
}
$v = explode("", trim($data->getBytes(), ' '));
return new PelEntryCopyright($v[0], $v[1]);
case PelTag::EXIF_VERSION:
case PelTag::FLASH_PIX_VERSION:
case PelTag::INTEROPERABILITY_VERSION:
if ($format != PelFormat::UNDEFINED) {
throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::UNDEFINED);
}
return new PelEntryVersion($tag, $data->getBytes() / 100);
case PelTag::USER_COMMENT:
if ($format != PelFormat::UNDEFINED) {
throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::UNDEFINED);
}
if ($data->getSize() < 8) {
return new PelEntryUserComment();
} else {
return new PelEntryUserComment($data->getBytes(8), rtrim($data->getBytes(0, 8)));
}
case PelTag::XP_TITLE:
case PelTag::XP_COMMENT:
case PelTag::XP_AUTHOR:
case PelTag::XP_KEYWORDS:
case PelTag::XP_SUBJECT:
if ($format != PelFormat::BYTE) {
throw new PelUnexpectedFormatException($this->type, $tag, $format, PelFormat::BYTE);
}
$v = '';
for ($i = 0; $i < $components; $i++) {
$b = $data->getByte($i);
/* Convert the byte to a character if it is non-null ---
* information about the character encoding of these entries
* would be very nice to have! So far my tests have shown
* that characters in the Latin-1 character set are stored in
* a single byte followed by a NULL byte. */
if ($b != 0) {
$v .= chr($b);
}
}
return new PelEntryWindowsString($tag, $v);
}
case self::GPS:
default:
/* Then handle the basic formats. */
switch ($format) {
case PelFormat::BYTE:
$v = new PelEntryByte($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getByte($i));
}
return $v;
case PelFormat::SBYTE:
$v = new PelEntrySByte($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getSByte($i));
}
return $v;
case PelFormat::ASCII:
return new PelEntryAscii($tag, $data->getBytes(0, -1));
case PelFormat::SHORT:
$v = new PelEntryShort($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getShort($i * 2));
}
return $v;
case PelFormat::SSHORT:
$v = new PelEntrySShort($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getSShort($i * 2));
}
return $v;
case PelFormat::LONG:
$v = new PelEntryLong($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getLong($i * 4));
}
return $v;
case PelFormat::SLONG:
$v = new PelEntrySLong($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getSLong($i * 4));
}
return $v;
case PelFormat::RATIONAL:
$v = new PelEntryRational($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getRational($i * 8));
}
return $v;
case PelFormat::SRATIONAL:
$v = new PelEntrySRational($tag);
for ($i = 0; $i < $components; $i++) {
$v->addNumber($data->getSRational($i * 8));
}
return $v;
case PelFormat::UNDEFINED:
return new PelEntryUndefined($tag, $data->getBytes());
default:
throw new PelException('Unsupported format: %s', PelFormat::getName($format));
}
}
}
/**
* Load data into a JPEG object.
*
* The data supplied will be parsed and turned into an object
* structure representing the image. This structure can then be
* manipulated and later turned back into an string of bytes.
*
* This methods can be called at any time after a JPEG object has
* been constructed, also after the {@link appendSection()} has been
* called to append custom sections. Loading several JPEG images
* into one object will accumulate the sections, but there will only
* be one {@link PelJpegMarker::SOS} section at any given time.
*
* @param PelDataWindow the data that will be turned into JPEG
* sections.
*/
function load(PelDataWindow $d)
{
Pel::debug('Parsing %d bytes...', $d->getSize());
/* JPEG data is stored in big-endian format. */
$d->setByteOrder(PelConvert::BIG_ENDIAN);
/* Run through the data to read the sections in the image. After
* each section is read, the start of the data window will be
* moved forward, and after the last section we'll terminate with
* no data left in the window. */
while ($d->getSize() > 0) {
/* JPEG sections start with 0xFF. The first byte that is not
* 0xFF is a marker (hopefully).
*/
for ($i = 0; $i < 7; $i++) {
if ($d->getByte($i) != 0xff) {
break;
}
}
$marker = $d->getByte($i);
if (!PelJpegMarker::isValid($marker)) {
throw new PelJpegInvalidMarkerException($marker, $i);
}
/* Move window so first byte becomes first byte in this
* section. */
$d->setWindowStart($i + 1);
if ($marker == PelJpegMarker::SOI || $marker == PelJpegMarker::EOI) {
$content = new PelJpegContent(new PelDataWindow());
$this->appendSection($marker, $content);
} else {
/* Read the length of the section. The length includes the
* two bytes used to store the length. */
$len = $d->getShort(0) - 2;
Pel::debug('Found %s section of length %d', PelJpegMarker::getName($marker), $len);
/* Skip past the length. */
$d->setWindowStart(2);
if ($marker == PelJpegMarker::APP1) {
try {
$content = new PelExif();
$content->load($d->getClone(0, $len));
} catch (PelInvalidDataException $e) {
/* We store the data as normal JPEG content if it could
* not be parsed as Exif data. */
$content = new PelJpegContent($d->getClone(0, $len));
}
$this->appendSection($marker, $content);
/* Skip past the data. */
$d->setWindowStart($len);
} elseif ($marker == PelJpegMarker::COM) {
$content = new PelJpegComment();
$content->load($d->getClone(0, $len));
$this->appendSection($marker, $content);
$d->setWindowStart($len);
} else {
$content = new PelJpegContent($d->getClone(0, $len));
$this->appendSection($marker, $content);
/* Skip past the data. */
$d->setWindowStart($len);
/* In case of SOS, image data will follow. */
if ($marker == PelJpegMarker::SOS) {
/* Some images have some trailing (garbage?) following the
* EOI marker. To handle this we seek backwards until we
* find the EOI marker. Any trailing content is stored as
* a PelJpegContent object. */
$length = $d->getSize();
while ($d->getByte($length - 2) != 0xff || $d->getByte($length - 1) != PelJpegMarker::EOI) {
$length--;
}
$this->jpeg_data = $d->getClone(0, $length - 2);
Pel::debug('JPEG data: ' . $this->jpeg_data->__toString());
/* Append the EOI. */
$this->appendSection(PelJpegMarker::EOI, new PelJpegContent(new PelDataWindow()));
/* Now check to see if there are any trailing data. */
if ($length != $d->getSize()) {
Pel::maybeThrow(new PelException('Found trailing content ' . 'after EOI: %d bytes', $d->getSize() - $length));
$content = new PelJpegContent($d->getClone($length));
/* We don't have a proper JPEG marker for trailing
* garbage, so we just use 0x00... */
$this->appendSection(0x0, $content);
}
/* Done with the loop. */
break;
}
}
}
}
/* while ($d->getSize() > 0) */
}
/**
* Check if data is valid TIFF data.
*
* This will read just enough data from the data window to determine
* if the data could be a valid TIFF data. This means that the
* check is more like a heuristic than a rigorous check.
*
* @param PelDataWindow $d
* the bytes that will be examined.
*
* @return boolean true if the data looks like valid TIFF data,
* false otherwise.
*
* @see PelJpeg::isValid()
*/
public static function isValid(PelDataWindow $d)
{
/* First check that we have enough data. */
if ($d->getSize() < 8) {
return false;
}
/* Byte order */
if ($d->strcmp(0, 'II')) {
$d->setByteOrder(PelConvert::LITTLE_ENDIAN);
} elseif ($d->strcmp(0, 'MM')) {
Pel::debug('Found Motorola byte order');
$d->setByteOrder(PelConvert::BIG_ENDIAN);
} else {
return false;
}
/* Verify the TIFF header */
return $d->getShort(2) == self::TIFF_HEADER;
}
function testReadBigIntegers()
{
$window = new PelDataWindow("‰«Íï", PelConvert::BIG_ENDIAN);
$this->assertEqual($window->getSize(), 4);
$this->assertEqual($window->getBytes(), "‰«Íï");
$this->assertEqual($window->getByte(0), 0x89);
$this->assertEqual($window->getByte(1), 0xab);
$this->assertEqual($window->getByte(2), 0xcd);
$this->assertEqual($window->getByte(3), 0xef);
$this->assertEqual($window->getShort(0), 0x89ab);
$this->assertEqual($window->getShort(1), 0xabcd);
$this->assertEqual($window->getShort(2), 0xcdef);
$this->assertEqual($window->getLong(0), 0x89abcdef);
$window->setByteOrder(PelConvert::LITTLE_ENDIAN);
$this->assertEqual($window->getSize(), 4);
$this->assertEqual($window->getBytes(), "‰«Íï");
$this->assertEqual($window->getByte(0), 0x89);
$this->assertEqual($window->getByte(1), 0xab);
$this->assertEqual($window->getByte(2), 0xcd);
$this->assertEqual($window->getByte(3), 0xef);
$this->assertEqual($window->getShort(0), 0xab89);
$this->assertEqual($window->getShort(1), 0xcdab);
$this->assertEqual($window->getShort(2), 0xefcd);
$this->assertEqual($window->getLong(0), 0xefcdab89);
}
