getid3_mp3::MPEGaudioHeaderValid( array $rawarray, bool $echoerrors = false, bool $allowBitrate15 = false ): bool

Compatibility

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

Parameters

$rawarrayarray

$echoerrorsbooloptional

Default: false

$allowBitrate15booloptional

Default: false

Return value

bool

Performance profile

How much work a call to getid3_mp3::MPEGaudioHeaderValid() 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

Trivial

Touches nothing outside its own arguments.

Scaling

Constant

No loop in the body: the same number of instructions runs whatever you pass in.

Instructions

6–87

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 133.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

3

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

What one call costs · 2 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost getid3_mp3::MPEGaudioHeaderValid() can have, taken from its control-flow graph on PHP 8.5.

Uses · 7

• getid3_mp3::MPEGaudioVersionArray()
• getid3_mp3::MPEGaudioLayerArray()
• getid3_mp3::MPEGaudioBitrateArray()
• getid3_mp3::MPEGaudioFrequencyArray()
• getid3_mp3::MPEGaudioChannelModeArray()
• getid3_mp3::MPEGaudioModeExtensionArray()
• getid3_mp3::MPEGaudioEmphasisArray()

Used by · 3

• getid3_mp3::MPEGaudioHeaderBytesValid()
• getid3_mp3::decodeMPEGaudioHeader()
• getid3_mp3::getOnlyMPEGaudioInfoBruteForce()

Source code

View on Trac ↗View on GitHub ↗

1846	public static function MPEGaudioHeaderValid($rawarray, $echoerrors=false, $allowBitrate15=false) {1847		if (!isset($rawarray['synch']) || ($rawarray['synch'] & 0x0FFE) != 0x0FFE) {1848			return false;1849		}1850 1851		static $MPEGaudioVersionLookup;1852		static $MPEGaudioLayerLookup;1853		static $MPEGaudioBitrateLookup;1854		static $MPEGaudioFrequencyLookup;1855		static $MPEGaudioChannelModeLookup;1856		static $MPEGaudioModeExtensionLookup;1857		static $MPEGaudioEmphasisLookup;1858		if (empty($MPEGaudioVersionLookup)) {1859			$MPEGaudioVersionLookup       = self::MPEGaudioVersionArray();1860			$MPEGaudioLayerLookup         = self::MPEGaudioLayerArray();1861			$MPEGaudioBitrateLookup       = self::MPEGaudioBitrateArray();1862			$MPEGaudioFrequencyLookup     = self::MPEGaudioFrequencyArray();1863			$MPEGaudioChannelModeLookup   = self::MPEGaudioChannelModeArray();1864			$MPEGaudioModeExtensionLookup = self::MPEGaudioModeExtensionArray();1865			$MPEGaudioEmphasisLookup      = self::MPEGaudioEmphasisArray();1866		}1867 1868		if (isset($MPEGaudioVersionLookup[$rawarray['version']])) {1869			$decodedVersion = $MPEGaudioVersionLookup[$rawarray['version']];1870		} else {1871			echo ($echoerrors ? "\n".'invalid Version ('.$rawarray['version'].')' : '');1872			return false;1873		}1874		if (isset($MPEGaudioLayerLookup[$rawarray['layer']])) {1875			$decodedLayer = $MPEGaudioLayerLookup[$rawarray['layer']];1876		} else {1877			echo ($echoerrors ? "\n".'invalid Layer ('.$rawarray['layer'].')' : '');1878			return false;1879		}1880		if (!isset($MPEGaudioBitrateLookup[$decodedVersion][$decodedLayer][$rawarray['bitrate']])) {1881			echo ($echoerrors ? "\n".'invalid Bitrate ('.$rawarray['bitrate'].')' : '');1882			if ($rawarray['bitrate'] == 15) {1883				// known issue in LAME 3.90 - 3.93.1 where free-format has bitrate ID of 15 instead of 01884				// let it go through here otherwise file will not be identified1885				if (!$allowBitrate15) {1886					return false;1887				}1888			} else {1889				return false;1890			}1891		}1892		if (!isset($MPEGaudioFrequencyLookup[$decodedVersion][$rawarray['sample_rate']])) {1893			echo ($echoerrors ? "\n".'invalid Frequency ('.$rawarray['sample_rate'].')' : '');1894			return false;1895		}1896		if (!isset($MPEGaudioChannelModeLookup[$rawarray['channelmode']])) {1897			echo ($echoerrors ? "\n".'invalid ChannelMode ('.$rawarray['channelmode'].')' : '');1898			return false;1899		}1900		if (!isset($MPEGaudioModeExtensionLookup[$decodedLayer][$rawarray['modeextension']])) {1901			echo ($echoerrors ? "\n".'invalid Mode Extension ('.$rawarray['modeextension'].')' : '');1902			return false;1903		}1904		if (!isset($MPEGaudioEmphasisLookup[$rawarray['emphasis']])) {1905			echo ($echoerrors ? "\n".'invalid Emphasis ('.$rawarray['emphasis'].')' : '');1906			return false;1907		}1908		// These are just either set or not set, you can't mess that up :)1909		// $rawarray['protection'];1910		// $rawarray['padding'];1911		// $rawarray['private'];1912		// $rawarray['copyright'];1913		// $rawarray['original'];1914 1915		return true;1916	}

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.mp3.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.

Corrections

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