diff options
Diffstat (limited to 'containerchan/matroska.php')
| -rw-r--r-- | containerchan/matroska.php | 524 |
1 files changed, 0 insertions, 524 deletions
diff --git a/containerchan/matroska.php b/containerchan/matroska.php deleted file mode 100644 index 5f1c38ee..00000000 --- a/containerchan/matroska.php +++ /dev/null @@ -1,524 +0,0 @@ -<?php -/* This file is dedicated to the public domain; you may do as you wish with it. */ - -// Information needed to parse an element type -class EBMLElementType { - public $name; - public $datatype; - public $validParents; -} - -// Information needed to parse all possible element types in a document -class EBMLElementTypeList { - private $_els; - private $_ids; - - public function __construct($filename) { - $lines = file($filename); - foreach($lines as $line) { - $fields = explode(' ', trim($line)); - $t = new EBMLElementType; - $id = hexdec($fields[0]); - $t->datatype = $fields[1]; - $t->name = $fields[2]; - $t->validParents = array(); - for ($i = 0; $i + 3 < count($fields); $i++) { - if ($fields[$i+3] == '*' || $fields[$i+3] == 'root') { - $t->validParents[$i] = $fields[$i+3]; - } else { - $t->validParents[$i] = hexdec($fields[$i+3]); - } - } - $this->_els[$id] = $t; - $this->_ids[strtoupper($t->name)] = $id; - } - } - - public function exists($id) { - return isset($this->_els[$id]); - } - - public function name($id) { - if (!isset($this->_els[$id])) return NULL; - return $this->_els[$id]->name; - } - - public function id($name) { - $name = strtoupper($name); - if (!isset($this->_ids[$name])) return NULL; - return $this->_ids[$name]; - } - - public function datatype($id) { - if ($id == 'root') return 'container'; - if (!isset($this->_els[$id])) return 'binary'; - return $this->_els[$id]->datatype; - } - - public function validChild($id1, $id2) { - if (!isset($this->_els[$id2])) return TRUE; - $parents = $this->_els[$id2]->validParents; - return in_array('*', $parents) || in_array($id1, $parents); - } -} - -// Matroska element types -global $EBML_ELEMENTS; -$EBML_ELEMENTS = new EBMLElementTypeList(dirname(__FILE__) . '/matroska-elements.txt'); - -// Decode big-endian integer -function ebmlDecodeInt($data, $signed=FALSE, $carryIn=0) { - $n = $carryIn; - if (strlen($data) > 8) throw new Exception('not supported: integer too long'); - for ($i = 0; $i < strlen($data); $i++) { - if ($n > (PHP_INT_MAX >> 8) || $n < ((-PHP_INT_MAX-1) >> 8)) { - $n = floatval($n); - } - $n = $n * 0x100 + ord($data[$i]); - if ($i == 0 && $signed && ($n & 0x80) != 0) { - $n -= 0x100; - } - } - return $n; -} - -// Decode big-endian IEEE float -function ebmlDecodeFloat($data) { - switch (strlen($data)) { - case 0: - return 0; - case 4: - switch(pack('f', 1e9)) { - case '(knN': - $arr = unpack('f', strrev($data)); - return $arr[1]; - case 'Nnk(': - $arr = unpack('f', $data); - return $arr[1]; - default: - error_log('cannot decode floats'); - return NULL; - } - case 8: - switch(pack('d', 1e9)) { - case "\x00\x00\x00\x00\x65\xcd\xcd\x41": - $arr = unpack('d', strrev($data)); - return $arr[1]; - case "\x41\xcd\xcd\x65\x00\x00\x00\x00": - $arr = unpack('d', $data); - return $arr[1]; - default: - error_log('cannot decode floats'); - return NULL; - } - default: - error_log('unsupported float length'); - return NULL; - } -} - -// Decode big-endian signed offset from Jan 01, 2000 in nanoseconds -// Convert to offset from Jan 01, 1970 in seconds -function ebmlDecodeDate($data) { - return ebmlDecodeInt($data, TRUE) * 1e-9 + 946684800; -} - -// Decode data of specified datatype -function ebmlDecode($data, $datatype) { - switch ($datatype) { - case 'int': return ebmlDecodeInt($data, TRUE); - case 'uint': return ebmlDecodeInt($data, FALSE); - case 'float': return ebmlDecodeFloat($data); - case 'string': return chop($data, "\0"); - case 'date': return ebmlDecodeDate($data); - case 'binary': return $data; - default: throw new Exception('unknown datatype'); - } -} - -// Methods for reading data from section of EBML file -class EBMLReader { - private $_fileHandle; - private $_offset; - private $_size; - private $_position; - - public function __construct($fileHandle, $offset=0, $size=NULL) { - $this->_fileHandle = $fileHandle; - $this->_offset = $offset; - $this->_size = $size; - $this->_position = 0; - } - - // Tell position within data section - public function position() { - return $this->_position; - } - - // Set position within data section - public function setPosition($position) { - $this->_position = $position; - } - - // Total size of data section (NULL if unknown) - public function size() { - return $this->_size; - } - - // Set end of data section - public function setSize($size) { - if ($this->_size === NULL) { - $this->_size = $size; - } else { - throw new Exception('size already set'); - } - } - - // Determine whether we are at end of data - public function endOfData() { - if ($this->_size === NULL) { - fseek($this->_fileHandle, $this->_offset + $this->_position); - fread($this->_fileHandle, 1); - if (feof($this->_fileHandle)) { - $this->_size = $this->_position; - return TRUE; - } else { - return FALSE; - } - } else { - return $this->_position >= $this->_size; - } - } - - // Create EBMLReader containing $size bytes and advance - public function nextSlice($size) { - $slice = new EBMLReader($this->_fileHandle, $this->_offset + $this->_position, $size); - if ($size !== NULL) { - $this->_position += $size; - if ($this->_size !== NULL && $this->_position > $this->_size) { - throw new Exception('unexpected end of data'); - } - } - return $slice; - } - - // Read entire region - public function readAll() { - if ($this->_size == 0) return ''; - if ($this->_size === NULL) throw new Exception('unknown length'); - fseek($this->_fileHandle, $this->_offset); - $data = fread($this->_fileHandle, $this->_size); - if ($data === FALSE || strlen($data) != $this->_size) { - throw new Exception('error reading from file'); - } - return $data; - } - - // Read $size bytes - public function read($size) { - return $this->nextSlice($size)->readAll(); - } - - // Read variable-length integer - public function readVarInt($signed=FALSE) { - // Read size and remove flag - $n = ord($this->read(1)); - $size = 0; - if ($n == 0) { - throw new Exception('not supported: variable-length integer too long'); - } - $flag = 0x80; - while (($n & $flag) == 0) { - $flag = $flag >> 1; - $size++; - } - $n -= $flag; - - // Read remaining data - $rawInt = $this->read($size); - - // Check for all ones - if ($n == $flag - 1 && $rawInt == str_repeat("\xFF", $size)) { - return NULL; - } - - // Range shift for signed integers - if ($signed) { - if ($flag == 0x01) { - $n = ord($rawInt[0]) - 0x80; - $rawInt = $rawInt.substr(1); - } else { - $n -= ($flag >> 1); - } - } - - // Convert to integer - $n = ebmlDecodeInt($rawInt, FALSE, $n); - - // Range shift for signed integers - if ($signed) { - if ($n == PHP_INT_MAX) { - $n = floatval($n); - } - $n++; - } - - return $n; - } -} - -// EBML element -class EBMLElement { - private $_id; - private $_name; - private $_datatype; - private $_content; - private $_headSize; - - public function __construct($id, $content, $headSize) { - global $EBML_ELEMENTS; - $this->_id = $id; - $this->_name = $EBML_ELEMENTS->name($this->_id); - $this->_datatype = $EBML_ELEMENTS->datatype($this->_id); - $this->_content = $content; - $this->_headSize = $headSize; - } - - public function id() {return $this->_id;} - public function name() {return $this->_name;} - public function datatype() {return $this->_datatype;} - public function content() {return $this->_content;} - public function headSize() {return $this->_headSize;} - - // Total size of element (including ID and datasize) - public function size() { - return $this->_headSize + $this->_content->size(); - } - - // Read and interpret content - public function value() { - if ($this->_datatype == 'binary') { - return $this->_content; - } else { - return ebmlDecode($this->_content->readAll(), $this->_datatype); - } - } -} - -// Iterate over EBML elements in data -class EBMLElementList extends EBMLElement implements Iterator { - private $_cache; - private $_position; - private static $MAX_ELEMENTS = 10000; - - public function __construct($id, $content, $headSize) { - parent::__construct($id, $content, $headSize); - $this->_cache = array(); - $this->_position = 0; - } - - public function rewind() { - $this->_position = 0; - } - - public function current() { - if ($this->valid()) { - return $this->_cache[$this->_position]; - } else { - return NULL; - } - } - - public function key() { - return $this->_position; - } - - public function next() { - $this->_position += $this->current()->size(); - if ($this->content()->size() !== NULL && $this->_position > $this->content()->size()) { - throw new Exception('unexpected end of data'); - } - } - - public function valid() { - global $EBML_ELEMENTS; - if (isset($this->_cache[$this->_position])) return TRUE; - $this->content()->setPosition($this->_position); - if ($this->content()->endOfData()) return FALSE; - $id = $this->content()->readVarInt(); - if ($id === NULL) throw new Exception('invalid ID'); - if ($this->content()->size() === NULL && !$EBML_ELEMENTS->validChild($this->id(), $id)) { - $this->content()->setSize($this->_position); - return FALSE; - } - $size = $this->content()->readVarInt(); - $headSize = $this->content()->position() - $this->_position; - $content = $this->content()->nextSlice($size); - if ($EBML_ELEMENTS->datatype($id) == 'container') { - $element = new EBMLElementList($id, $content, $headSize); - } else { - if ($size === NULL) { - throw new Exception('non-container element of unknown size'); - } - $element = new EBMLElement($id, $content, $headSize); - } - $this->_cache[$this->_position] = $element; - return TRUE; - } - - // Total size of element (including ID and size) - public function size() { - if ($this->content()->size() === NULL) { - $iElement = 0; - foreach ($this as $element) { // iterate over elements to find end - $iElement++; - if ($iElement > self::$MAX_ELEMENTS) throw new Exception('not supported: too many elements'); - } - } - return $this->headSize() + $this->content()->size(); - } - - // Read and interpret content - public function value() { - return $this; - } - - // Get element value by name - public function get($name, $defaultValue=NULL) { - $iElement = 0; - foreach ($this as $element) { - $iElement++; - if ($iElement > self::$MAX_ELEMENTS) throw new Exception('not supported: too many elements'); - if (strtoupper($element->name()) == strtoupper($name)) { - return $element->value(); - } - } - return $defaultValue; - } -} - -// Parse block -class MatroskaBlock { - const LACING_NONE = 0; - const LACING_XIPH = 1; - const LACING_EBML = 3; - const LACING_FIXED = 2; - public $trackNumber; - public $timecode; - public $keyframe; - public $invisible; - public $lacing; - public $discardable; - public $frames; - - public function __construct($reader) { - # Header - $this->trackNumber = $reader->readVarInt(); - $this->timecode = ebmlDecodeInt($reader->read(2), TRUE); - $flags = ord($reader->read(1)); - if (($flags & 0x70) != 0) { - throw new Exception('reserved flags set'); - } - $this->keyframe = (($flags & 0x80) != 0); - $this->invisible = (($flags & 0x08) != 0); - $this->lacing = ($flags >> 1) & 0x03; - $this->discardable = (($flags & 0x01) != 0); - - # Lacing sizes - if ($this->lacing == self::LACING_NONE) { - $nsizes = 0; - } else { - $nsizes = ord($reader->read(1)); - } - $sizes = array(); - switch ($this->lacing) { - case self::LACING_XIPH: - for ($i = 0; $i < $nsizes; $i++) { - $size = 0; - $x = 255; - while ($x == 255) { - $x = ord($reader->read(1)); - $size += $x; - if ($size > 65536) throw new Exception('not supported: laced frame too long'); - } - $sizes[$i] = $size; - } - break; - case self::LACING_EBML: - $size = 0; - for ($i = 0; $i < $nsizes; $i++) { - $dsize = $reader->readVarInt($i != 0); - if ($dsize === NULL || $size + $dsize < 0) { - throw new Exception('invalid frame size'); - } - $size += $dsize; - $sizes[$i] = $size; - } - break; - case self::LACING_FIXED: - $lenRemaining = $reader->size() - $reader->position(); - if ($lenRemaining % ($nsizes + 1) != 0) { - throw new Exception('data size not divisible by frame count'); - } - $size = (int) ($lenRemaining / ($nsizes + 1)); - for ($i = 0; $i < $nsizes; $i++) { - $sizes[$i] = $size; - } - break; - } - - # Frames - $this->frames = array(); - for ($i = 0; $i < $nsizes; $i++) { - $this->frames[$i] = $reader->nextSlice($sizes[$i]); - } - $this->frames[$nsizes] = $reader->nextSlice($reader->size() - $reader->position()); - } -} - -// Create element list from $fileHandle -function readMatroska($fileHandle) { - $reader = new EBMLReader($fileHandle); - if ($reader->read(4) != "\x1a\x45\xdf\xa3") { - throw new Exception('not an EBML file'); - } - $root = new EBMLElementList('root', $reader, 0); - $header = $root->get('EBML'); - $ebmlVersion = $header->get('EBMLReadVersion', 1); - $docType = $header->get('DocType'); - $docTypeVersion = $header->get('DocTypeReadVersion', 1); - if ($ebmlVersion != 1) { - throw new Exception('unsupported EBML version'); - } - if ($docType != 'matroska' && $docType != 'webm') { - throw new Exception ('unsupported document type'); - } - if ($docTypeVersion < 1 || $docTypeVersion > 4) { - throw new Exception ('unsupported document type version'); - } - return $root; -} - -function ebmlEncodeVarInt($n) { - $data = ''; - $flag = 0x80; - while ($n >= $flag) { - if ($flag == 0) { - throw new Exception('not supported: number too large'); - } - $data = chr($n & 0xFF) . $data; - $n = $n >> 8; - $flag = $flag >> 1; - } - $data = chr($n | $flag) . $data; - return $data; -} - -function ebmlEncodeElementName($name) { - global $EBML_ELEMENTS; - return ebmlEncodeVarInt($EBML_ELEMENTS->id($name)); -} - -function ebmlEncodeElement($name, $content) { - return ebmlEncodeElementName($name) . ebmlEncodeVarInt(strlen($content)) . $content; -} |