AudioScheduledSourceNode: start() method
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
js
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
.
js
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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