比方说下面这段代码：
const navigator = window.navigator
navigator.getUserMedia = navigator.getUserMedia ||
navigator.webkitGetUserMedia ||
navigator.mozGetUserMedia ||
navigator.msGetUserMedia
const AudioContext = window.AudioContext ||
window.webkitAudioContext
const isSupport = !!(navigator.getUserMedia && AudioContext)
const context = isSupport && new AudioContext()
export default {
isSupport,
start () {
// https://developer.mozilla.org/zh-CN/docs/Web/API/AudioContext AudioContent API
return new Promise((resolve, reject) => {
navigator.getUserMedia({audio: true}, stream => {
const source = context.createMediaStreamSource(stream)
const analyser = context.createAnalyser()
source.connect(analyser)
analyser.fftSize = 2048
resolve(analyser)
}, () => {
reject()
})
})
},
getVoiceSize (analyser) {
const dataArray = new Uint8Array(analyser.frequencyBinCount)
analyser.getByteFrequencyData(dataArray)
const data = dataArray.slice(100, 1000)
const sum = data.reduce((a, b) => a + b)
return sum
}
}
)
)
)
)
