JS30 day23 Speech Synthesis

Posted by Anthony Chao on 2019-11-24

JS30 day23 - Speech Synthesis

作業內容

最近做的都跟聲音有關,雖然概念上不複雜但我覺得 Google 能把這個東西實作出來放在瀏覽器真的太猛了吧 = =,這個作業自己覺得比較難的部分是理解整個 google 系統是怎麼把聲音的資訊結合成物件

學到什麼

  • JS

    1. SpeechSynthesisUtterance() 物件為 Web Speech API 中代表一發音的需求,翻成白話文就是一段話的資訊,例如內容,語言、音調、聲音、速率等,我們可以透過 console log 看看這個物件的組成:
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    SpeechSynthesisUtterance {text: "", lang: "", voice: null, volume: -1, rate: -1, …}

    發出聲音的方式是用下面的方式來說:

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    SpeechSynthesis.speak(<SpeechSynthesisUtterance實體>)

    上面這句的 SpeechSynthesis 介面是語音合成伺服器的控制器,可透過其來取得可使用的語音合成資訊,並播放或暫停發音等相關功能

    1. speechSynthesis.addEventListener('voiceschanged', populatVoices)
      voiceschanged 事件是當 SpeechSynthesis.getVoices() 改變時被觸發,它也是 SpeechSynthesis 唯一的一個事件。
      這裡會被觸發,Bos 是說因為 SpeechSynthesis 被讀取所以觸發了這個事件

    2. SpeechSynthesis.getVoices():取得一陣列,其中包含目前所有的 SpeechSynthesisVoice 物件,其裡頭的屬性為當下環境支援的所有發音資訊,晚點必須選擇其中一個給 msg 這個實體才有辦法發出聲音
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    function populateVoices(){
    voices = this.getVoices()
    console.log(voices)
    }

    參考資料:https://ithelp.ithome.com.tw/articles/10196799

    1. 現在要做出在下拉選單選擇不同語言就要發出不同語言的聲音
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    function setVoice(){
    msg.voice = voices.find(voice => voice.name === this.value)
    }
    voicesDropdown.addEventListener('change', setVoice)
    1. 做出切換語言同時直接中段前一個然後發聲音
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    function setVoice(){
    msg.voice = voices.find(voice => voice.name === this.value)
    toggle()
    }

    function toggle(startOver = true){
    speechSynthesis.cancel()
    if (startOver){
    speechSynthesis.speak(msg)
    }
    }
    1. 監聽 scroll bar 跟 text 變化
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    function setOption(){
    console.log(this.name, this.value);
    msg[${this.name}] = this.value;
    toggle();
    }
    options.forEach(option => {
    option.addEventListener('change', setOption)
    })

    1. 綁定 stopButton 事件的時候注意不能這樣寫
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    stopButton.addEventListener('click', toggle(false))

    這樣會只有在一開始的時候觸發一次,按鍵本身沒作用,所以有兩種寫法
    bind() 會生成一個新的綁定函式,第一個值是 this 的值,後面的才是第 1,2,3…個參數

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    stopButton.addEventListener('click', toggle.bind(null, false))  
    // 或者
    stopButton.addEventListener('click', () => toggle(false))
    1. 經過自己分析之後,發出聲音的步驟可以拆解如下如下
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    //1.把瀏覽器可以發出的聲音列出來,放在下拉選單(window 會比 mac 少),這邊的 this 是 speechSynthesis
    voices = this.getVoices()
    //2.根據使用者選的下拉選單,把指定的這個 vioce 物件塞回去給 SpeechSynthesisUtterance 生出來的實體 msg
    msg.voice = voices.find(voice => voice.name === this.value)
    //3.根據 input 不同改變這段 msg 的內容 / 速度 / 音高
    msg[this.name] = this.value
    //4.包裝成 toggle function 發出聲音,如果傳入的參數是 false 就可以不發出聲音
    function toggle(startOver = true){
    speechSynthesis.cancel()
    if (startOver){
    speechSynthesis.speak(msg)
    }
    }

參考資料:
https://github.com/wesbos/JavaScript30

code 內容:

HTML:

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<div class="voiceinator">

<h1>The Voiceinator 5000</h1>

<select name="voice" id="voices">
<option value="">Select A Voice</option>
</select>

<label for="rate">Rate:</label>
<input name="rate" type="range" min="0" max="3" value="1" step="0.1">

<label for="pitch">Pitch:</label>

<input name="pitch" type="range" min="0" max="2" step="0.1">
<textarea name="text">Hello! I love JavaScript 👍</textarea>
<button id="stop">Stop!</button>
<button id="speak">Speak</button>
<option value=""></option>

CSS:

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html {
font-size: 10px;
box-sizing: border-box;
}

*, *:before, *:after {
box-sizing: inherit;
}

body {
margin: 0;
padding: 0;
font-family: sans-serif;
background-color: #3BC1AC;
display: flex;
min-height: 100vh;
align-items: center;

background-image:
radial-gradient(circle at 100% 150%, #3BC1AC 24%, #42D2BB 25%, #42D2BB 28%, #3BC1AC 29%, #3BC1AC 36%, #42D2BB 36%, #42D2BB 40%, transparent 40%, transparent),
radial-gradient(circle at 0 150%, #3BC1AC 24%, #42D2BB 25%, #42D2BB 28%, #3BC1AC 29%, #3BC1AC 36%, #42D2BB 36%, #42D2BB 40%, transparent 40%, transparent),
radial-gradient(circle at 50% 100%, #42D2BB 10%, #3BC1AC 11%, #3BC1AC 23%, #42D2BB 24%, #42D2BB 30%, #3BC1AC 31%, #3BC1AC 43%, #42D2BB 44%, #42D2BB 50%, #3BC1AC 51%, #3BC1AC 63%, #42D2BB 64%, #42D2BB 71%, transparent 71%, transparent),
radial-gradient(circle at 100% 50%, #42D2BB 5%, #3BC1AC 6%, #3BC1AC 15%, #42D2BB 16%, #42D2BB 20%, #3BC1AC 21%, #3BC1AC 30%, #42D2BB 31%, #42D2BB 35%, #3BC1AC 36%, #3BC1AC 45%, #42D2BB 46%, #42D2BB 49%, transparent 50%, transparent),
radial-gradient(circle at 0 50%, #42D2BB 5%, #3BC1AC 6%, #3BC1AC 15%, #42D2BB 16%, #42D2BB 20%, #3BC1AC 21%, #3BC1AC 30%, #42D2BB 31%, #42D2BB 35%, #3BC1AC 36%, #3BC1AC 45%, #42D2BB 46%, #42D2BB 49%, transparent 50%, transparent);
background-size:100px 50px;
}

.voiceinator {
padding: 2rem;
width: 50rem;
margin: 0 auto;
border-radius: 1rem;
position: relative;
background: white;
overflow: hidden;
z-index: 1;
box-shadow: 0 0 5px 5px rgba(0,0,0,0.1);
}

h1 {
width: calc(100% + 4rem);
margin: -2rem 0 2rem -2rem;
padding: .5rem;
background: #ffc600;
border-bottom: 5px solid #F3C010;
text-align: center;
font-size: 5rem;
font-weight: 100;
font-family: 'Pacifico', cursive;
text-shadow: 3px 3px 0 #F3C010;
}

.voiceinator input,
.voiceinator button,
.voiceinator select,
.voiceinator textarea {
width: 100%;
display: block;
margin: 10px 0;
padding: 10px;
border: 0;
font-size: 2rem;
background: #F7F7F7;
outline: 0;
}

textarea {
height: 20rem;
}

input[type="select"] {

}

.voiceinator button {
background: #ffc600;
border: 0;
width: 49%;
float: left;
font-family: 'Pacifico', cursive;
margin-bottom: 0;
font-size: 2rem;
border-bottom: 5px solid #F3C010;
cursor: pointer;
position: relative;
}

.voiceinator button:active {
top: 2px;
}

.voiceinator button:nth-of-type(1) {
margin-right: 2%;
}

JS:

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const msg = new SpeechSynthesisUtterance();
let voices = [];
const voicesDropdown = document.querySelector('[name="voice"]');
const options = document.querySelectorAll('[type="range"], [name="text"]');
const speakButton = document.querySelector('#speak');
const stopButton = document.querySelector('#stop');
msg.text = document.querySelector('[name="text"]').value

function populateVoices(){
voices = this.getVoices()
const voiceOptions = voices
.map( voice => { return `<option value="${voice.name}">${voice.name}(${voice.lang})</option>`})
.join('')
voicesDropdown.innerHTML = voiceOptions
}

function setVoice(){
msg.voice = voices.find(voice => voice.name === this.value)
toggle()
}

function toggle(startOver = true){
speechSynthesis.cancel()
if (startOver){
speechSynthesis.speak(msg)
}
}

function setOption(){
msg[this.name] = this.value;
toggle();
}

speechSynthesis.addEventListener('voiceschanged', populateVoices)
voicesDropdown.addEventListener('change', setVoice)
options.forEach(option => {
option.addEventListener('change', setOption)
})
speakButton.addEventListener('click', toggle.bind(null, false))
stopButton.addEventListener('click', toggle(false))




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