--- title: AudioBuffer.duration slug: Web/API/AudioBuffer/duration translation_of: Web/API/AudioBuffer/duration ---
{{ APIRef("Web Audio API") }}
{{domxref("AudioBuffer")}}接口的duration属性返回一个双精度数,表示缓冲区中存储的PCM数据的持续时间(以秒为单位)
var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate); myArrayBuffer.duration;
双精度值
// Stereo var channels = 2; // Create an empty two second stereo buffer at the // sample rate of the AudioContext var frameCount = audioCtx.sampleRate * 2.0; var myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate); button.onclick = function() { // Fill the buffer with white noise; // just random values between -1.0 and 1.0 for (var channel = 0; channel < channels; channel++) { // This gives us the actual ArrayBuffer that contains the data var nowBuffering = myArrayBuffer.getChannelData(channel); for (var i = 0; i < frameCount; i++) { // Math.random() is in [0; 1.0] // audio needs to be in [-1.0; 1.0] nowBuffering[i] = Math.random() * 2 - 1; } } console.log(myArrayBuffer.duration); }
Specification | Status | Comment |
---|---|---|
{{SpecName('Web Audio API', '#widl-AudioBuffer-duration', 'duration')}} | {{Spec2('Web Audio API')}} |
Feature | Chrome | Edge | Firefox (Gecko) | Internet Explorer | Opera | Safari (WebKit) |
---|---|---|---|---|---|---|
Basic support | 14 {{property_prefix("webkit")}} | {{CompatVersionUnknown}} | 23 | {{CompatNo}} | 15 {{property_prefix("webkit")}} 22 (unprefixed) |
6 {{property_prefix("webkit")}} |
Feature | Android | Chrome | Edge | Firefox Mobile (Gecko) | Firefox OS | IE Phone | Opera Mobile | Safari Mobile |
---|---|---|---|---|---|---|---|---|
Basic support | {{CompatNo}} | 28 {{property_prefix("webkit")}} | {{CompatVersionUnknown}} | 25 | 1.2 | {{CompatNo}} | {{CompatNo}} | 6 {{property_prefix("webkit")}} |