Calculate measure and beat durations in seconds
PhpTabs provides some useful methods to calculate durations.
Below, 2 examples of use:
Measure duration
To calculate duration in seconds, the formula is
(Number of beats) * 60 / Tempo
The following code prints duration for the first measure of the first track.
<?php
require __DIR__ . '/vendor/autoload.php';
use PhpTabs\PhpTabs;
// Instanciate a tablature
$song = new PhpTabs('myTab.gp5');
// Take a measure
$measure = $song->getTrack(0)->getMeasure(0);
// Calculate duration in seconds
$duration = 60
* $measure->getTimeSignature()->getNumerator()
/ $measure->getTempo()->getValue();
// Print duration
echo sprintf("Duration=%ss", $duration);
With a 4/4 time signature and a tempo of 120, this example will ouput:
Duration=2s
Beat duration
Calculating beat duration in seconds is quite more complex. It depends on:
- tempo
- time signature
- non dotted, dotted or double dotted beat
- division type
PhpTabs (>=0.6.0) provides a shortcut method to easily get this value.
The getTime() method is provided by the \PhpTabs\Music\Voice model.
The following code prints duration for the first beat of the first measure of the first track.
<?php
require __DIR__ . '/vendor/autoload.php';
use PhpTabs\PhpTabs;
// Instanciate a tablature
$song = new PhpTabs('myTab.gp5');
// Take a beat
$beat = $song->getTrack(0)->getMeasure(0)->getBeat(0);
// Get duration in seconds for the first voice
$duration = $beat->getVoice(0)->getTime();
// Print duration
echo sprintf("Duration=%ss", $duration);
With a 4/4 time signature, a tempo of 120 and for a quarter beat, this example will ouput:
Duration=0.5s