AudioScheduledSourceNode: start() method
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.
The start()
method on AudioScheduledSourceNode
schedules a sound to begin playback at the specified time.
If no time is specified, then the sound begins playing immediately.
Syntax
start()
start(when)
Parameters
when
Optional-
The time, in seconds, at which the sound should begin to play. This value is specified in the same time coordinate system as the
AudioContext
is using for itscurrentTime
attribute. A value of 0 (or omitting thewhen
parameter entirely) causes the sound to start playback immediately.
Return value
None (undefined
).
Exceptions
InvalidStateNode
DOMException
-
Thrown if the node has already been started. This error occurs even if the node is no longer running because of a prior call to
stop()
. RangeError
-
Thrown if the value specified for
when
is negative.
Examples
This example demonstrates how to create an OscillatorNode
which is
scheduled to start playing in 2 seconds and stop playing 1 second after that. The times
are calculated by adding the desired number of seconds to the context's current time
stamp returned by AudioContext.currentTime
.
context = new AudioContext();
osc = context.createOscillator();
osc.connect(context.destination);
/* Schedule the start and stop times for the oscillator */
osc.start(context.currentTime + 2);
osc.stop(context.currentTime + 3);
Specifications
Specification |
---|
Web Audio API # dom-audioscheduledsourcenode-start |
Browser compatibility
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