################## Web Audio API ################## .. contents:: :local: API ====================== BaseAudioContext ---------------------- Also implements methods from the interface EventTarget. createBuffer() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a new, empty AudioBuffer object, which can then be populated by data and played via an AudioBufferSourceNode. createConstantSource() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a ConstantSourceNode object, which is an audio source that continuously outputs a monaural (one-channel) sound signal whose samples all have the same value. createBufferSource() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates an AudioBufferSourceNode, which can be used to play and manipulate audio data contained within an AudioBuffer object. AudioBuffers are created using AudioContext.createBuffer or returned by AudioContext.decodeAudioData when it successfully decodes an audio track. createScriptProcessor() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a ScriptProcessorNode, which can be used for direct audio processing via JavaScript. createStereoPanner() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a StereoPannerNode , which can be used to apply stereo panning to an audio source. createAnalyser() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates an AnalyserNode, which can be used to expose audio time and frequency data and for example to create data visualisations. createBiquadFilter() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a BiquadFilterNode, which represents a second order filter configurable as several different common filter types: high-pass, low-pass, band-pass, etc. createChannelMerger() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a ChannelMergerNode, which is used to combine channels from multiple audio streams into a single audio stream. createChannelSplitter() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a ChannelSplitterNode , which is used to access the individual channels of an audio stream and process them separately. createConvolver() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a ConvolverNode, which can be used to apply convolution effects to your audio graph, for example a reverberation effect. createDelay() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a DelayNode , which is used to delay the incoming audio signal by a certain amount. This node is also useful to create feedback loops in a Web Audio API graph. createDynamicsCompressor() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a DynamicsCompressorNode, which can be used to apply acoustic compression to an audio signal. createGain() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a GainNode, which can be used to control the overall volume of the audio graph. createIIRFilter() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates an IIRFilterNode , which represents a second order filter configurable as several different common filter types. createOscillator() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates an OscillatorNode, a source representing a periodic waveform. It basically generates a tone. createPanner() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a PannerNode , which is used to spatialise an incoming audio stream in 3D space. createPeriodicWave() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a PeriodicWave, used to define a periodic waveform that can be used to determine the output of an OscillatorNode. createWaveShaper() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a WaveShaperNode, which is used to implement non-linear distortion effects. decodeAudioData() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Asynchronously decodes audio file data contained in an ArrayBuffer. In this case, the ArrayBuffer is usually loaded from an XMLHttpRequest's response attribute after setting the responseType to arraybuffer. This method only works on complete files, not fragments of audio files. resume() ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Resumes the progression of time in an audio context that has previously been suspended/paused. AudioContext -------------------------- The AudioContext interface represents an audio-processing graph built from audio modules linked together, each represented by an AudioNode. AudioContext 接口是一个音频处理图，它由音频模块连接在一起构成，每个音频模块是一个 AudioNode An audio context controls both the creation of the nodes it contains and the execution of the audio processing, or decoding. You need to create an AudioContext before you do anything else, as everything happens inside a context. It's recommended to create one AudioContext and reuse it instead of initializing a new one each time, and it's OK to use a single AudioContext for several different audio sources and pipeline concurrently. createMediaElementSource ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Creates a MediaElementAudioSourceNode associated with an HTMLMediaElement. This can be used to play and manipulate audio from