getID3::ChannelsBitratePlaytimeCalculations()

Compatibility

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

Performance profile

How much work a call to getID3::ChannelsBitratePlaytimeCalculations() 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

43–142

Executed per call on PHP 8.5, depending on the branch taken. The body compiles to 250.

Plugin surface

None

Nothing here hands control to plugin code.

Called by

1

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

What one call costs · 4 distinct outcomes

One number would be a lie: the work depends on which branch runs. These are every distinct cost getID3::ChannelsBitratePlaytimeCalculations() can have, taken from its control-flow graph on PHP 8.5.

This body has more branch combinations than are worth enumerating, so the table covers the outcomes found first rather than every one that exists.

Uses · 3

• getid3_lib::PlaytimeString()
• getID3::include_module()
• getid3_riff::fourccLookup()

Used by · 1

• getID3::analyze()analyze file

Source code

View on Trac ↗View on GitHub ↗

1892	public function ChannelsBitratePlaytimeCalculations() {1893 1894		// set channelmode on audio1895		if (!empty($this->info['audio']['channelmode']) || !isset($this->info['audio']['channels'])) {1896			// ignore1897		} elseif ($this->info['audio']['channels'] == 1) {1898			$this->info['audio']['channelmode'] = 'mono';1899		} elseif ($this->info['audio']['channels'] == 2) {1900			$this->info['audio']['channelmode'] = 'stereo';1901		}1902 1903		// Calculate combined bitrate - audio + video1904		$CombinedBitrate  = 0;1905		$CombinedBitrate += (isset($this->info['audio']['bitrate']) && ($this->info['audio']['bitrate'] != 'free') ? $this->info['audio']['bitrate'] : 0);1906		$CombinedBitrate += (isset($this->info['video']['bitrate'])                                                ? $this->info['video']['bitrate'] : 0);1907		if (($CombinedBitrate > 0) && empty($this->info['bitrate'])) {1908			$this->info['bitrate'] = $CombinedBitrate;1909		}1910		//if ((isset($this->info['video']) && !isset($this->info['video']['bitrate'])) || (isset($this->info['audio']) && !isset($this->info['audio']['bitrate']))) {1911		//	// for example, VBR MPEG video files cannot determine video bitrate:1912		//	// should not set overall bitrate and playtime from audio bitrate only1913		//	unset($this->info['bitrate']);1914		//}1915 1916		// video bitrate undetermined, but calculable1917		if (isset($this->info['video']['dataformat']) && $this->info['video']['dataformat'] && (!isset($this->info['video']['bitrate']) || ($this->info['video']['bitrate'] == 0))) {1918			// if video bitrate not set1919			if (isset($this->info['audio']['bitrate']) && ($this->info['audio']['bitrate'] > 0) && ($this->info['audio']['bitrate'] == $this->info['bitrate'])) {1920				// AND if audio bitrate is set to same as overall bitrate1921				if (isset($this->info['playtime_seconds']) && ($this->info['playtime_seconds'] > 0)) {1922					// AND if playtime is set1923					if (isset($this->info['avdataend']) && isset($this->info['avdataoffset'])) {1924						// AND if AV data offset start/end is known1925						// THEN we can calculate the video bitrate1926						$this->info['bitrate'] = round((($this->info['avdataend'] - $this->info['avdataoffset']) * 8) / $this->info['playtime_seconds']);1927						$this->info['video']['bitrate'] = $this->info['bitrate'] - $this->info['audio']['bitrate'];1928					}1929				}1930			}1931		}1932 1933		if ((!isset($this->info['playtime_seconds']) || ($this->info['playtime_seconds'] <= 0)) && !empty($this->info['bitrate'])) {1934			$this->info['playtime_seconds'] = (($this->info['avdataend'] - $this->info['avdataoffset']) * 8) / $this->info['bitrate'];1935		}1936 1937		if (!isset($this->info['bitrate']) && !empty($this->info['playtime_seconds'])) {1938			$this->info['bitrate'] = (($this->info['avdataend'] - $this->info['avdataoffset']) * 8) / $this->info['playtime_seconds'];1939		}1940		if (isset($this->info['bitrate']) && empty($this->info['audio']['bitrate']) && empty($this->info['video']['bitrate'])) {1941			if (isset($this->info['audio']['dataformat']) && empty($this->info['video']['resolution_x'])) {1942				// audio only1943				$this->info['audio']['bitrate'] = $this->info['bitrate'];1944			} elseif (isset($this->info['video']['resolution_x']) && empty($this->info['audio']['dataformat'])) {1945				// video only1946				$this->info['video']['bitrate'] = $this->info['bitrate'];1947			}1948		}1949 1950		// Set playtime string1951		if (!empty($this->info['playtime_seconds']) && empty($this->info['playtime_string'])) {1952			$this->info['playtime_string'] = getid3_lib::PlaytimeString($this->info['playtime_seconds']);1953		}1954 1955		// Look up codec name if fourcc is set but codec is not1956		if (!empty($this->info['video']['fourcc']) && !isset($this->info['video']['codec'])) {1957			$this->include_module('audio-video.riff');1958			$this->info['video']['codec'] = getid3_riff::fourccLookup($this->info['video']['fourcc']);1959		}1960	}

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

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