ScriptProcessorNode: audioprocess event
Deprecated: This feature is no longer recommended. Though some browsers might still support it, it may have already been removed from the relevant web standards, may be in the process of being dropped, or may only be kept for compatibility purposes. Avoid using it, and update existing code if possible; see the compatibility table at the bottom of this page to guide your decision. Be aware that this feature may cease to work at any time.
The audioprocess event of the ScriptProcessorNode interface is fired when an input buffer of a script processor is ready to be processed.
Note:
This feature was replaced by AudioWorklets and the AudioWorkletNode interface.
This event is not cancelable and does not bubble.
Syntax
Use the event name in methods like addEventListener(), or set an event handler property.
addEventListener("audioprocess", (event) => { })
onaudioprocess = (event) => { }
Event type
An AudioProcessingEvent. Inherits from Event.
Event properties
Also implements the properties inherited from its parent, Event.
playbackTimeRead only-
A double representing the time when the audio will be played, as defined by the time of
AudioContext.currentTime. inputBufferRead only-
An
AudioBufferthat is the buffer containing the input audio data to be processed. The number of channels is defined as a parameternumberOfInputChannels, of the factory methodAudioContext.createScriptProcessor(). Note that the returnedAudioBufferis only valid in the scope of the event handler. outputBufferRead only-
An
AudioBufferthat is the buffer where the output audio data should be written. The number of channels is defined as a parameter,numberOfOutputChannels, of the factory methodAudioContext.createScriptProcessor(). Note that the returnedAudioBufferis only valid in the scope of the event handler.
Examples
scriptNode.addEventListener("audioprocess", (audioProcessingEvent) => {
// The input buffer is a song we loaded earlier
const inputBuffer = audioProcessingEvent.inputBuffer;
// The output buffer contains the samples that will be modified and played
const outputBuffer = audioProcessingEvent.outputBuffer;
// Loop through the output channels (in this case there is only one)
for (let channel = 0; channel < outputBuffer.numberOfChannels; channel++) {
const inputData = inputBuffer.getChannelData(channel);
const outputData = outputBuffer.getChannelData(channel);
// Loop through the 4096 samples
for (let sample = 0; sample < inputBuffer.length; sample++) {
// make output equal to the same as the input
outputData[sample] = inputData[sample];
// add noise to each output sample
outputData[sample] += (Math.random() * 2 - 1) * 0.2;
}
}
});
You could also set up the event handler using the onaudioprocess property:
scriptNode.onaudioprocess = (audioProcessingEvent) => {
// …
};
Specifications
This feature does not appear to be defined in any specification.Browser compatibility
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audioprocess event
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Legend
Tip: you can click/tap on a cell for more information.
- Full support
- Full support
- Deprecated. Not for use in new websites.