getid3_matroska::parseEBML( array $info )

Compatibility

Present in every tracked release (6.7.7 to 7.1.0), and compiles on PHP 7.4 through 8.6-dev.

Parameters

$infoarray

Performance profile

How much work a call to getid3_matroska::parseEBML() does, and what it touches: the algorithmic scaling, the Zend instruction count per call across PHP versions, the hooks it hands control to, and the core code that calls it. Measured from the compiled opcodes, not a stopwatch, so every number is identical on any machine running the same PHP version, and every function in core is ranked by cost.

Cost class

Light

Touches nothing outside its own arguments.

Scaling

Scales with input

The body loops, so the work grows with what you pass in.

Instructions

13–137

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 1756.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

2

2 places in core call this, so the cost is paid more often than your own code shows.

What one call costs · 3 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost getid3_matroska::parseEBML() can have, taken from its control-flow graph on PHP 8.5.

Uses · 16

• getid3_matroska::getEBMLelement()
• getid3_lib::BigEndian2Int()
• getid3_lib::trimNullByte()
• getid3_matroska::unhandledElement()
• getid3_matroska::EBML2Int()
• getid3_matroska::EBMLidName()
• getid3_matroska::warning()
• getid3_lib::PrintHexBytes()
• getid3_lib::BigEndian2Float()ANSI/IEEE Standard 754-1985, Standard for Binary Floating Point Arithmetic
• getid3_matroska::readEBMLelementData()
• getid3_matroska::EBMLdate2unix()
• getid3_matroska::TargetTypeValue()

Used by · 2

• getid3_matroska::Analyze()
• getid3_matroska::scanStartEndForClusters()Scan start and end of file for cluster information when Duration is missing Only use this if no Duration was found in the Info element and we are not in parse_whole_file mode

Source code

View on Trac ↗View on GitHub ↗

578	private function parseEBML(&$info) {579		// http://www.matroska.org/technical/specs/index.html#EBMLBasics580		$this->current_offset = $info['avdataoffset'];581 582		while ($this->getEBMLelement($top_element, $info['avdataend'])) {583			switch ($top_element['id']) {584 585				case EBML_ID_EBML:586					$info['matroska']['header']['offset'] = $top_element['offset'];587					$info['matroska']['header']['length'] = $top_element['length'];588 589					while ($this->getEBMLelement($element_data, $top_element['end'], true)) {590						switch ($element_data['id']) {591 592							case EBML_ID_EBMLVERSION:593							case EBML_ID_EBMLREADVERSION:594							case EBML_ID_EBMLMAXIDLENGTH:595							case EBML_ID_EBMLMAXSIZELENGTH:596							case EBML_ID_DOCTYPEVERSION:597							case EBML_ID_DOCTYPEREADVERSION:598								$element_data['data'] = getid3_lib::BigEndian2Int($element_data['data']);599								break;600 601							case EBML_ID_DOCTYPE:602								$element_data['data'] = getid3_lib::trimNullByte($element_data['data']);603								$info['matroska']['doctype'] = $element_data['data'];604								$info['fileformat'] = $element_data['data'];605								break;606 607							default:608								$this->unhandledElement('header', __LINE__, $element_data);609								break;610						}611 612						unset($element_data['offset'], $element_data['end']);613						$info['matroska']['header']['elements'][] = $element_data;614					}615					break;616 617				case EBML_ID_SEGMENT:618					$info['matroska']['segment'][0]['offset'] = $top_element['offset'];619					$info['matroska']['segment'][0]['length'] = $top_element['length'];620 621					while ($this->getEBMLelement($element_data, $top_element['end'])) {622						if ($element_data['id'] != EBML_ID_CLUSTER || !$this->hide_clusters) { // collect clusters only if required623							$info['matroska']['segments'][] = $element_data;624						}625						switch ($element_data['id']) {626 627							case EBML_ID_SEEKHEAD: // Contains the position of other level 1 elements.628 629								while ($this->getEBMLelement($seek_entry, $element_data['end'])) {630									switch ($seek_entry['id']) {631 632										case EBML_ID_SEEK: // Contains a single seek entry to an EBML element633											while ($this->getEBMLelement($sub_seek_entry, $seek_entry['end'], true)) {634 635												switch ($sub_seek_entry['id']) {636 637													case EBML_ID_SEEKID:638														$seek_entry['target_id']   = self::EBML2Int($sub_seek_entry['data']);639														$seek_entry['target_name'] = self::EBMLidName($seek_entry['target_id']);640														break;641 642													case EBML_ID_SEEKPOSITION:643														$seek_entry['target_offset'] = $element_data['offset'] + getid3_lib::BigEndian2Int($sub_seek_entry['data']);644														break;645 646													default:647														$this->unhandledElement('seekhead.seek', __LINE__, $sub_seek_entry);												}648														break;649											}650											if (!isset($seek_entry['target_id'])) {651												$this->warning('seek_entry[target_id] unexpectedly not set at '.$seek_entry['offset']);652												break;653											}654											if (($seek_entry['target_id'] != EBML_ID_CLUSTER) || !$this->hide_clusters) { // collect clusters only if required655												$info['matroska']['seek'][] = $seek_entry;656											}657											break;

Changelog

Unchanged from 6.7.7 through 7.1.0.

1. 6.7.7
2. 6.8.8
3. 6.9.7
4. 7.0.4
5. 7.1.0

Signature, return type and hooks compared across 5 parsed releases.

About this page

Parsed data

Generated from the wordpress-develop 7.1.0 tag, from src/wp-includes/ID3/module.audio-video.matroska.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

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