start

Summary

Schedules a sound to playback at an exact time, with options.

Method of apis/webaudio/AudioBufferSourceNode apis/webaudio/AudioBufferSourceNode

Syntax

var  = AudioBufferSourceNode.start(when, offset, duration);

Parameters

when

Data-type: Number

Describes at what time (in seconds) the sound should start playing. It is in the same time coordinate system as AudioContext.currentTime. If 0 is passed in for this value or if the value is less than currentTime, then the sound will start playing immediately. start may only be called one time and must be called before stop is called or an exception will be thrown.

offset

Data-type: Number

(Optional)

Describes the offset time in the buffer (in seconds) where playback will begin. This parameter is optional with a default value of 0 (playing back from the beginning of the buffer).

duration

Data-type: Number

(Optional)

Describes the duration of the portion (in seconds) to be played. This parameter is optional, with the default value equal to the total duration of the AudioBuffer minus the offset parameter. Thus if neither offset nor duration are specified then the implied duration is the total duration of the AudioBuffer.

Return Value

Returns an object of type

Examples

Play the entire sound from the beginning.

var source = audioCtx.createBufferSource();
source.start();

Play, after a 1 second delay, starting at second 3, the next 10 seconds of the sound (seconds 3 through 12).

var source = audioCtx.createBufferSource();
source.start(1,3,10);

Related specifications

Web Audio API: W3C Editor’s Draft