From 33058f2b292b3a581333bdfb21b8f671898c5060 Mon Sep 17 00:00:00 2001 From: Peter Bengtsson Date: Tue, 8 Dec 2020 14:40:17 -0500 Subject: initial commit --- files/zh-cn/web/api/baseaudiocontext/index.html | 292 ++++++++++++++++++++++++ 1 file changed, 292 insertions(+) create mode 100644 files/zh-cn/web/api/baseaudiocontext/index.html (limited to 'files/zh-cn/web/api/baseaudiocontext/index.html') diff --git a/files/zh-cn/web/api/baseaudiocontext/index.html b/files/zh-cn/web/api/baseaudiocontext/index.html new file mode 100644 index 0000000000..5d11d7fe82 --- /dev/null +++ b/files/zh-cn/web/api/baseaudiocontext/index.html @@ -0,0 +1,292 @@ +--- +title: BaseAudioContext +slug: Web/API/BaseAudioContext +tags: + - API + - Audio + - BaseAudioContext + - Interface + - NeedsTranslation + - Reference + - TopicStub + - Web Audio API +translation_of: Web/API/BaseAudioContext +--- +
{{APIRef("Web Audio API")}}
+ +

The BaseAudioContext interface acts as a base definition for online and offline audio-processing graphs, as represented by {{domxref("AudioContext")}} and {{domxref("OfflineAudioContext")}} respectively. You wouldn't use BaseAudioContext directly — you'd use its features via one of these two inheriting interfaces.

+ +

A BaseAudioContext can be a target of events, therefore it implements the {{domxref("EventTarget")}} interface.

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{{InheritanceDiagram}}

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Properties

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+
{{domxref("BaseAudioContext.audioWorklet")}} {{experimental_inline}} {{readonlyInline}}
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Returns the {{domxref("AudioWorklet")}} object, used for creating custom AudioNodes with JavaScript processing.
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{{domxref("BaseAudioContext.currentTime")}} {{readonlyInline}}
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Returns a double representing an ever-increasing hardware time in seconds used for scheduling. It starts at 0.
+
{{domxref("BaseAudioContext.destination")}} {{readonlyInline}}
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Returns an {{domxref("AudioDestinationNode")}} representing the final destination of all audio in the context. It can be thought of as the audio-rendering device.
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{{domxref("BaseAudioContext.listener")}} {{readonlyInline}}
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Returns the {{domxref("AudioListener")}} object, used for 3D spatialization.
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{{domxref("BaseAudioContext.sampleRate")}} {{readonlyInline}}
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Returns a float representing the sample rate (in samples per second) used by all nodes in this context. The sample-rate of an {{domxref("AudioContext")}} cannot be changed.
+
{{domxref("BaseAudioContext.state")}} {{readonlyInline}}
+
Returns the current state of the AudioContext.
+
+ +

Event handlers

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{{domxref("BaseAudioContext.onstatechange")}}
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An event handler that runs when an event of type {{event("statechange")}} has fired. This occurs when the AudioContext's state changes, due to the calling of one of the state change methods ({{domxref("AudioContext.suspend")}}, {{domxref("AudioContext.resume")}}, or {{domxref("AudioContext.close")}}).
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+ +

Methods

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Also implements methods from the interface {{domxref("EventTarget")}}.

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{{domxref("BaseAudioContext.createBuffer()")}}
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Creates a new, empty {{ domxref("AudioBuffer") }} object, which can then be populated by data and played via an {{ domxref("AudioBufferSourceNode") }}.
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{{domxref("BaseAudioContext.createConstantSource()")}}
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Creates a {{domxref("ConstantSourceNode")}} object, which is an audio source that continuously outputs a monaural (one-channel) sound signal whose samples all have the same value.
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{{domxref("BaseAudioContext.createBufferSource()")}}
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Creates an {{domxref("AudioBufferSourceNode")}}, which can be used to play and manipulate audio data contained within an {{ domxref("AudioBuffer") }} object. {{ domxref("AudioBuffer") }}s are created using {{domxref("AudioContext.createBuffer")}} or returned by {{domxref("AudioContext.decodeAudioData")}} when it successfully decodes an audio track.
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{{domxref("BaseAudioContext.createScriptProcessor()")}}
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Creates a {{domxref("ScriptProcessorNode")}}, which can be used for direct audio processing via JavaScript.
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{{domxref("BaseAudioContext.createStereoPanner()")}}
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Creates a {{domxref("StereoPannerNode")}}, which can be used to apply stereo panning to an audio source.
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{{domxref("BaseAudioContext.createAnalyser()")}}
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Creates an {{domxref("AnalyserNode")}}, which can be used to expose audio time and frequency data and for example to create data visualisations.
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{{domxref("BaseAudioContext.createBiquadFilter()")}}
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Creates a {{domxref("BiquadFilterNode")}}, which represents a second order filter configurable as several different common filter types: high-pass, low-pass, band-pass, etc.
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{{domxref("BaseAudioContext.createChannelMerger()")}}
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Creates a {{domxref("ChannelMergerNode")}}, which is used to combine channels from multiple audio streams into a single audio stream.
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{{domxref("BaseAudioContext.createChannelSplitter()")}}
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Creates a {{domxref("ChannelSplitterNode")}}, which is used to access the individual channels of an audio stream and process them separately.
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{{domxref("BaseAudioContext.createConvolver()")}}
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Creates a {{domxref("ConvolverNode")}}, which can be used to apply convolution effects to your audio graph, for example a reverberation effect.
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{{domxref("BaseAudioContext.createDelay()")}}
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Creates a {{domxref("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.
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{{domxref("BaseAudioContext.createDynamicsCompressor()")}}
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Creates a {{domxref("DynamicsCompressorNode")}}, which can be used to apply acoustic compression to an audio signal.
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{{domxref("BaseAudioContext.createGain()")}}
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Creates a {{domxref("GainNode")}}, which can be used to control the overall volume of the audio graph.
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{{domxref("BaseAudioContext.createIIRFilter()")}}
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Creates an {{domxref("IIRFilterNode")}}, which represents a second order filter configurable as several different common filter types.
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{{domxref("BaseAudioContext.createOscillator()")}}
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Creates an {{domxref("OscillatorNode")}}, a source representing a periodic waveform. It basically generates a tone.
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{{domxref("BaseAudioContext.createPanner()")}}
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Creates a {{domxref("PannerNode")}}, which is used to spatialise an incoming audio stream in 3D space.
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{{domxref("BaseAudioContext.createPeriodicWave()")}}
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Creates a {{domxref("PeriodicWave")}}, used to define a periodic waveform that can be used to determine the output of an {{ domxref("OscillatorNode") }}.
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{{domxref("BaseAudioContext.createWaveShaper()")}}
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Creates a {{domxref("WaveShaperNode")}}, which is used to implement non-linear distortion effects.
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{{domxref("BaseAudioContext.decodeAudioData()")}}
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Asynchronously decodes audio file data contained in an {{domxref("ArrayBuffer")}}. In this case, the ArrayBuffer is usually loaded from an {{domxref("XMLHttpRequest")}}'s response attribute after setting the responseType to arraybuffer. This method only works on complete files, not fragments of audio files.
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{{domxref("BaseAudioContext.resume()")}}
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Resumes the progression of time in an audio context that has previously been suspended/paused.
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Examples

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Basic audio context declaration:

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var audioCtx = new AudioContext();
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Cross browser variant:

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var AudioContext = window.AudioContext || window.webkitAudioContext;
+var audioCtx = new AudioContext();
+
+var oscillatorNode = audioCtx.createOscillator();
+var gainNode = audioCtx.createGain();
+var finish = audioCtx.destination;
+// etc.
+ +

Specifications

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SpecificationStatusComment
{{SpecName('Web Audio API', '#BaseAudioContext', 'BaseAudioContext')}}{{Spec2('Web Audio API')}} 
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Browser compatibility

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{{CompatibilityTable}}
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FeatureChromeEdgeFirefox (Gecko)Internet ExplorerOperaSafari (WebKit)
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatNo}}15.0{{property_prefix("webkit")}}
+ 22		6.0{{property_prefix("webkit")}}
baseLatency{{CompatChrome(60)}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
createConstantSource(){{CompatChrome(56)}}{{CompatNo}}{{CompatGeckoDesktop(52)}}{{CompatNo}}{{CompatOpera(43)}}{{CompatNo}}
createStereoPanner(){{CompatChrome(42)}}{{CompatVersionUnknown}}{{CompatGeckoDesktop(37.0)}} {{CompatNo}}{{CompatNo}}{{CompatNo}}
onstatechange, state, suspend(), resume(){{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatGeckoDesktop(40.0)}}{{CompatNo}}{{CompatNo}}{{CompatSafari(8.0)}}
Unprefixed{{CompatVersionUnknown}}{{CompatVersionUnknown}}    
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FeatureAndroid WebviewChrome for AndroidEdgeFirefox Mobile (Gecko)Firefox OSIE MobileOpera MobileSafari Mobile
Basic support{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}2.2{{CompatNo}}{{CompatVersionUnknown}}{{CompatNo}}
baseLatency{{CompatChrome(60)}}{{CompatChrome(60)}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}
createConstantSource(){{CompatChrome(56)}}{{CompatChrome(56)}}{{CompatNo}}{{CompatGeckoMobile(52)}}{{CompatNo}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
createStereoPanner(){{CompatChrome(42)}}{{CompatChrome(42)}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
onstatechange, state, suspend(), resume(){{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatNo}}{{CompatNo}}{{CompatNo}}
Unprefixed{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatVersionUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatUnknown}}{{CompatOperaMobile(43)}}{{CompatUnknown}}
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See also

+ + -- cgit v1.2.3-54-g00ecf