/**
* Parses the buffer stream for a meta event
*
* @since 1.0
* @uses read()
* @uses Util::unpack()
* @uses getDelta()
* @uses getMetaEvent()
*
* @return MetaEvent
*/
protected function parseMetaEvent()
{
$metaEventType = Util::unpack($this->read(1, true));
$metaEventType = $metaEventType[0];
$length = $this->getDelta();
$data = $this->read($length, true);
return $this->getMetaEvent($metaEventType, $data);
}
/**
* @since 1.0
* @uses getChunkClass()
* @uses formatOffset()
* @uses Delta::toBinary()
* @uses Util::binaryToHex()
* @uses Event::toBinary()
* @uses Event::getLength()
* @uses Delta::getLength()
*
* @param Event $event
* @return string
*/
public function beforeEvent(Event $event)
{
if ($this->delta === null) {
return '';
}
$class = $this->getChunkClass($event);
$text = "<tr class=\"{$class}\">" . $this->formatOffset($this->offset);
$deltaHex = Util::binaryToHex($this->delta->toBinary());
$delta = '<span class="delta">' . wordwrap(implode(' ', $deltaHex), 23, '<br />') . '</span>';
$eventHex = Util::binaryToHex($event->toBinary());
$lineLength = 23 - strlen(implode(' ', $deltaHex)) % 23;
$eventSegment = wordwrap(implode(' ', $eventHex), $lineLength, '|');
$bar = strpos($eventSegment, '|');
if ($bar !== false) {
$eventSegment = substr($eventSegment, 0, $bar) . '<br />' . wordwrap(substr($eventSegment, $bar + 1), 23, '<br />');
}
$text .= '<td><tt>' . $delta . ' ' . $eventSegment . '</tt></td>';
$this->offset += $event->getLength() + $this->delta->getLength();
return $text;
}
/**
* Gets a binary representation of this event
*
* @since 1.0
* @uses Util::pack()
*
* @return binary
*/
public function toBinary()
{
$binary = $this->isContinuation() ? '' : Util::pack($this->getType() | $this->channel);
if ($this->param2 !== null) {
$binary .= Util::pack($this->param1, $this->param2);
} else {
$binary .= Util::pack($this->param1);
}
return $binary;
}
/**
* Reads a delta time from the buffer stream
*
* @since 1.0
* @uses read()
* @uses Util::unpack()
* @uses Util::getTicksFromDeltaByteSequence()
*
* @return int The number of clock ticks in the delta time
*/
protected function getDelta()
{
$byte = $this->read(1, true);
$value = Util::unpack($byte);
$delta = '';
while ($this->file->valid() && $value[0] > 0x7f) {
$delta .= $byte;
$byte = $this->read(1);
$value = Util::unpack($byte);
}
if ($byte !== null) {
$delta .= $byte;
}
return Util::getTicksFromDeltaByteSequence($delta);
}
/**
* Gets whether this is a normal system exclusive event
*
* Normal sysex events are signified by the last byte of data
* being 0xF7.
*
* @since 1.0
* @uses Util::pack()
* @see isDivided()
*
* @return bool
*/
public function isNormal()
{
$byte = end($this->data);
reset($this->data);
return $byte === Util::pack(0xf7);
}
/**
* Gets the binary representation of this meta event
*
* @since 1.0
* @uses Util::pack()
* @uses Util::getDeltaByteSequence()
* @uses getSubtype()
*
* @return binary
*/
public function toBinary()
{
if (is_array($this->data)) {
$data = '';
foreach ($this->data as $datum) {
$data .= Util::pack($datum);
}
} else {
$data = $this->data;
}
return Util::pack($this->getType(), $this->getSubtype()) . Util::getDeltaByteSequence($this->length) . $data;
}
/**
* Parses the given track header
*
* @since 1.0
* @uses TrackHeader::LENGTH
* @uses Util::unpack()
*
* @param binary $header
* @throws InvalidArgumentException
* @throws {@link ParseException} if the header is invalid
* @return TrackHeader
*/
public function parseTrackHeader($header)
{
/*if (strlen($header) !== TrackHeader::LENGTH) {
throw new \InvalidArgumentException('Track header must be ' . \Midi\TrackHeader::LENGTH . ' bytes');
}*/
$id = Util::unpack(substr($header, 0, 4));
$size = array_reverse(Util::unpack(substr($header, 4)));
if ($id !== array(0x4d, 0x54, 0x72, 0x6b)) {
throw new ParseException('Invalid track header, expected [4D 54 72 6B]');
}
$shift = 0;
$trackSize = 0;
foreach ($size as $byte) {
$trackSize |= $byte << $shift;
$shift += 8;
}
return new TrackHeader($trackSize);
}
/**
* Parses the given file header
*
* @since 1.0
* @uses FileHeader::LENGTH
* @uses Util::unpack()
*
* @param binary $header
* @throws InvalidArgumentException
* @throws {@link ParseException} if the file header is not a valid MIDI file header
* @return FileHeader
*/
public function parseFileHeader($header)
{
if (strlen($header) !== FileHeader::LENGTH) {
throw new \InvalidArgumentException('MIDI file header must be ' . FileHeader::LENGTH . ' bytes');
}
$id = Util::unpack(substr($header, 0, 4));
$chunkSize = Util::unpack(substr($header, 4, 4));
$format = Util::unpack(substr($header, 8, 2));
$tracks = Util::unpack(substr($header, 10, 2));
$timeDivision = Util::unpack(substr($header, 12, 2));
if ($id !== array(0x4d, 0x54, 0x68, 0x64)) {
throw new ParseException('Invalid file header, expected byte sequence [4D 54 68 64]');
}
if ($chunkSize !== array(0x0, 0x0, 0x0, 0x6)) {
throw new ParseException('File header chunk size must be [00 00 00 06]');
}
$format = $format[0] << 8 | $format[1];
$timeDivision = $timeDivision[0] << 8 | $timeDivision[1];
$tracks = $tracks[0] << 8 | $tracks[1];
if ($format !== 0 && $format !== 1 && $format !== 2) {
throw new ParseException('MIDI file format must be 0, 1 or 2 (got ' . $format . ')');
}
return new FileHeader($format, $tracks, $timeDivision);
}
