AudioNode.md

AudioNode

Namespace: SpawnDev.SpawnJS.JSObjects
Inheritance: SpawnJSObject -> EventTarget -> AudioNode
MDN Reference: AudioNode

The AudioNode class is the base interface for all audio processing modules in the Web Audio API. An audio node can be a source (e.g., OscillatorNode, AudioBufferSourceNode), a processing node (e.g., GainNode, BiquadFilterNode, AnalyserNode), or a destination (AudioDestinationNode). Nodes are connected together to form an audio processing graph where audio flows from sources through processors to the destination.

Constructors

Signature	Description
AudioNode(SpawnJSObjectReference _ref)	Deserialization constructor.

Properties

Property	Type	Description
Context	BaseAudioContext	The associated BaseAudioContext (the audio graph this node belongs to).
NumberOfInputs	int	The number of inputs feeding the node. Source nodes have 0 inputs.
NumberOfOutputs	int	The number of outputs coming out of the node. Destination nodes have 0 outputs.
ChannelCount	int	The number of channels used when up-mixing and down-mixing connections to any inputs.
ChannelCountMode	string	How channels are matched between inputs and outputs: "max", "clamped-max", or "explicit".
ChannelInterpretation	string	The meaning of the channels: "speakers" (positional audio) or "discrete" (individual channels).

Methods

Method	Return Type	Description
Connect(AudioNode audioNode)	AudioNode	Connects this node's output to another AudioNode's input. Returns the destination node for chaining.
Connect(AudioParam audioParam)	void	Connects this node's output to an AudioParam, allowing the node's output to automate the parameter value.
Disconnect()	void	Disconnects this node from all nodes it is connected to.
Disconnect(AudioNode audioNode)	void	Disconnects this node from a specific AudioNode.
Disconnect(AudioParam audioParam)	void	Disconnects this node from a specific AudioParam.

AudioNode Subclasses

The Web Audio API provides many specialized nodes, all inheriting from AudioNode:

Node	Category	Description
OscillatorNode	Source	Generates periodic waveforms (sine, square, sawtooth, triangle).
AudioBufferSourceNode	Source	Plays audio from an AudioBuffer.
MediaElementAudioSourceNode	Source	Receives audio from an HTML <audio> or <video> element.
MediaStreamAudioSourceNode	Source	Receives audio from a MediaStream (e.g., microphone).
GainNode	Processing	Controls volume (gain).
BiquadFilterNode	Processing	Configurable filter (low-pass, high-pass, band-pass, etc.).
AnalyserNode	Processing	Provides frequency and time-domain analysis data for visualizations.
DelayNode	Processing	Delays audio by a specified time.
ConvolverNode	Processing	Applies convolution (reverb, spatial effects).
DynamicsCompressorNode	Processing	Applies dynamic range compression.
WaveShaperNode	Processing	Applies non-linear distortion.
StereoPannerNode	Processing	Stereo left/right panning.
PannerNode	Processing	3D spatial audio panning.
ChannelSplitterNode	Processing	Splits a multi-channel stream into individual channels.
ChannelMergerNode	Processing	Merges multiple channels into one stream.
AudioDestinationNode	Destination	The final output (speakers/headphones).
MediaStreamAudioDestinationNode	Destination	Outputs to a MediaStream.

Example

using var audioCtx = new AudioContext();

// Build an audio processing graph:
// Oscillator -> Gain -> Filter -> Analyser -> Destination

using var oscillator = audioCtx.CreateOscillator();
using var gain = audioCtx.CreateGain();
using var filter = audioCtx.CreateBiquadFilter();
using var analyser = audioCtx.CreateAnalyser();

// Connect nodes to form the graph (chaining with return value)
oscillator.Connect(gain);
gain.Connect(filter);
filter.Connect(analyser);
analyser.Connect(audioCtx.Destination);

// Inspect node properties
Console.WriteLine($"Gain inputs: {gain.NumberOfInputs}");     // 1
Console.WriteLine($"Gain outputs: {gain.NumberOfOutputs}");    // 1
Console.WriteLine($"Channel count: {gain.ChannelCount}");      // 2

// Change channel configuration
gain.ChannelCountMode = "explicit";
gain.ChannelInterpretation = "speakers";

// Connect a node's output to an AudioParam (modulation)
// This makes the oscillator's output control the gain value
using var lfo = audioCtx.CreateOscillator();
lfo.Frequency.Value = 5; // 5 Hz tremolo
lfo.Connect(gain.Gain);   // Connect to the Gain AudioParam
lfo.Start();

// Disconnect and reconnect
gain.Disconnect(filter);   // Disconnect from filter specifically
gain.Connect(analyser);    // Bypass the filter

// Disconnect everything
oscillator.Disconnect();   // Disconnects from all destinations