We're looking for a user researcher to understand the needs of developers and designers. Is this you or someone you know? Check out the post: https://mzl.la/2IGzdXS

BiquadFilterNode

这篇翻译不完整。请帮忙从英语翻译这篇文章

这是一个实验中的功能
此功能某些浏览器尚在开发中,请参考浏览器兼容性表格以得到在不同浏览器中适合使用的前缀。由于该功能对应的标准文档可能被重新修订,所以在未来版本的浏览器中该功能的语法和行为可能随之改变。

BiquadFilterNode() 构造函数创建一个新的BiquadFilterNode对象, 这个对象通过AudioContext.createBiquadFilter()方法创建,表示一个简单的低阶滤波器.

语法

var biquadFilterNode = new BiquadFilterNode(context, options)

参数

context
AudioContext 的一个引用.
options可选
可选配置项如下:
  • type: 值为其中之一"lowpass", "highpass", "bandpass", "lowshelf", "highshelf", "peaking", "notch", "allpass". 其他选项的含义取决于此选项的值.

低通滤波器: 允许低于截止频率的频率通过, and attenuates frequencies above the cutoff. This is a standard second-order resonant lowpass filter with 12dB/octave rolloff.

  • Q: Controls how peaked the response will be at the cutoff frequency. A large value makes the response more peaked. Please note that for this filter type, this value is not a traditional Q, but is a resonance value in decibels.
  • frequency: The cutoff frequency.
  • gain: Not used.

highpass: A highpass filter is the opposite of a lowpass filter. Frequencies above the cutoff frequency are passed through, but frequencies below the cutoff are attenuated. It implements a standard second-order resonant highpass filter with 12dB/octave rolloff.

  • Q: Controls how peaked the response will be at the cutoff frequency. A large value makes the response more peaked. Please note that for this filter type, this value is not a traditional Q, but is a resonance value in decibels.
  • frequency: The cutoff frequency.
  • gain: Not used.

bandpass: A bandpass filter allows a range of frequencies to pass through and attenuates the frequencies below and above this frequency range. It implements a second-order bandpass filter.

  • Q: Controls the width of the band. The width becomes narrower as the Q value increases.
  • frequency: The center of the frequency band.
  • gain: Not used.

lowshelf: The lowshelf filter allows all frequencies through, but adds a boost (or attenuation) to the lower frequencies. It implements a second-order lowshelf filter.

  • Q: Not used.
  • frequency: The upper limit of the frequences where the boost, or attenuation, is applied.
  • gain: The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

highshelf: The highshelf filter is the opposite of the lowshelf filter and allows all frequencies through, but adds a boost to the higher frequencies. It implements a second-order highshelf filter.

  • Q: Not used.
  • frequency: The lower limit of the frequences where the boost, or attenuation, is applied.
  • gain: The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

peaking: The peaking filter allows all frequencies through, adding a boost, or attenuation, to a range of frequencies.

  • Q: The width of the band of frequencies that are boosted. A large value implies a narrow width.
  • frequency: The center frequency of the boost range.
  • gain: The boost, in dB, to be applied. If the value is negative, the frequencies are attenuated.

notch: The notch filter (also known as a band-stop, or band-rejection filter) is the opposite of a bandpass filter. It allows all frequencies through, except for a set of frequencies.

  • Q: The width of the band of frequencies that are attenuated. A large value implies a narrow width.
  • frequency: The center frequency of the attenuation range.
  • gain: Not used.

allpass: An allpass filter allows all frequencies through, but changes the phase relationship between the various frequencies. It implements a second-order allpass filter.

  • Q: The sharpness of the phase transition at the center frequency. A larger value implies a sharper transition and a larger group delay.
  • frequency: The frequency where the center of the phase transition occurs. Viewed another way, this is the frequency with maximal group delay.
  • gain: Not used.

Specifications

Specification Status Comment
Web Audio API
BiquadFilterNode()
Working Draft Initial definition.

Browser Compatibility

We're converting our compatibility data into a machine-readable JSON format. This compatibility table still uses the old format, because we haven't yet converted the data it contains. Find out how you can help!

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 55.0 ? ? 42 ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support 未实现 55.0 ? ? ? 42 ? 55.0

文档标签和贡献者

此页面的贡献者: huangxok
最后编辑者: huangxok,