语音识别（Web Speech API）

近期看了一个语音识别的dome—–Web Speech API
本api为js调用云端接口识别
个人测试了一下，响应速度还是比较快的
注意：本API与官网需翻墙使用和访问
展示效果：
页面代码如下：
<!DOCTYPE html>
<meta charset="utf-8">
<title>Web Speech API Demo</title>
<style>
  * {
    font-family: Verdana, Arial, sans-serif;
  }
  a:link {
    color:#000;
    text-decoration: none;
  }
  a:visited {
    color:#000;
  }
  a:hover {
    color:#33F;
  }
  .button {
    background: -webkit-linear-gradient(top,#008dfd 0,#0370ea 100%);
    border: 1px solid #076bd2;
    border-radius: 3px;
    color: #fff;
    display: none;
    font-size: 13px;
    font-weight: bold;
    line-height: 1.3;
    padding: 8px 25px;
    text-align: center;
    text-shadow: 1px 1px 1px #076bd2;
    letter-spacing: normal;
  }
  .center {
    padding: 10px;
    text-align: center;
  }
  .final {
    color: black;
    padding-right: 3px;
  }
  .interim {
    color: gray;
  }
  .info {
    font-size: 14px;
    text-align: center;
    color: #777;
    display: none;
  }
  .right {
    float: right;
  }
  .sidebyside {
    display: inline-block;
    width: 45%;
    min-height: 40px;
    text-align: left;
    vertical-align: top;
  }
  #headline {
    font-size: 40px;
    font-weight: 300;
  }
  #info {
    font-size: 20px;
    text-align: center;
    color: #777;
    visibility: hidden;
  }
  #results {
    font-size: 14px;
    font-weight: bold;
    border: 1px solid #ddd;
    padding: 15px;
    text-align: left;
    min-height: 150px;
  }
  #start_button {
    border: 0;
    background-color:transparent;
    padding: 0;
  }
</style>
<h1 class="center" id="headline">
  <a href="http://dvcs.w3.org/hg/speech-api/raw-file/tip/speechapi.html" rel="external nofollow" >
    Web Speech API</a> 语音识别</h1>
<div id="info">
  <p id="info_start">点击下话筒开始说话</p>
  <p id="info_speak_now">正在讲话。。。</p>
  <p id="info_no_speech">未检测到语音。您可能需要调整
    <a href="//support.google.com/chrome/bin/answer.py?hl=en&amp;answer=1407892" rel="external nofollow"  rel="external nofollow" >
      microphone settings</a>.</p>
  <p id="info_no_microphone" style="display:none">
           找不到麦克风。确保安装了麦克风，
    <a href="//support.google.com/chrome/bin/answer.py?hl=en&amp;answer=1407892" rel="external nofollow"  rel="external nofollow" >
    microphone settings</a> 配置正确</p>
  <p id="info_allow">单击上面的“允许”按钮启用麦克风。</p>
  <p id="info_denied">拒绝使用麦克风。</p>
  <p id="info_blocked">禁止使用麦克风。要改变，
    前往： chrome://settings/contentExceptions#media-stream</p>
  <p id="info_upgrade">此浏览器不支持Web语音API。
     升级到 <a href="//www.google.com/chrome" rel="external nofollow" >Chrome</a>
     版本25或更高</p>
</div>
<div class="right">
  <button id="start_button" onclick="startButton(event)">
    <img id="start_img" src="mic.gif" alt="Start"></button>
</div>
<div id="results">
  <span id="final_span" class="final"></span>
  <span id="interim_span" class="interim"></span>
  <p>
</div>
<div class="center">
  <div class="sidebyside" style="text-align:right">
    <button id="copy_button" class="button" onclick="copyButton()">
      Copy and Paste</button>
    <div id="copy_info" class="info">
      Press Control-C to copy text.<br>(Command-C on Mac.)
    </div>
  </div>
  <div class="sidebyside">
    <button id="email_button" class="button" onclick="emailButton()">
      Create Email</button>
    <div id="email_info" class="info">
      Text sent to default email application.<br>
      (See chrome://settings/handlers to change.)
    </div>
  </div>
  <p>
  <div id="div_language">
    <select id="select_language" onchange="updateCountry()"></select>
    &nbsp;&nbsp;
    <select id="select_dialect"></select>
  </div>
</div>
<script>
var langs =
[['Afrikaans',       ['af-ZA']],
 ['Bahasa Indonesia',['id-ID']],
 ['Bahasa Melayu',   ['ms-MY']],
 ['Català',          ['ca-ES']],
 ['Čeština',         ['cs-CZ']],
 ['Deutsch',         ['de-DE']],
 ['English',         ['en-AU', 'Australia'],
                     ['en-CA', 'Canada'],
                     ['en-IN', 'India'],
                     ['en-NZ', 'New Zealand'],
                     ['en-ZA', 'South Africa'],
                     ['en-GB', 'United Kingdom'],
                     ['en-US', 'United States']],
 ['Español',         ['es-AR', 'Argentina'],
                     ['es-BO', 'Bolivia'],
                     ['es-CL', 'Chile'],
                     ['es-CO', 'Colombia'],
                     ['es-CR', 'Costa Rica'],
                     ['es-EC', 'Ecuador'],
                     ['es-SV', 'El Salvador'],
                     ['es-ES', 'España'],
                     ['es-US', 'Estados Unidos'],
                     ['es-GT', 'Guatemala'],
                     ['es-HN', 'Honduras'],
                     ['es-MX', 'México'],
                     ['es-NI', 'Nicaragua'],
                     ['es-PA', 'Panamá'],
                     ['es-PY', 'Paraguay'],
                     ['es-PE', 'Perú'],
                     ['es-PR', 'Puerto Rico'],
                     ['es-DO', 'República Dominicana'],
                     ['es-UY', 'Uruguay'],
                     ['es-VE', 'Venezuela']],
 ['Euskara',         ['eu-ES']],
 ['Français',        ['fr-FR']],
 ['Galego',          ['gl-ES']],
 ['Hrvatski',        ['hr_HR']],
 ['IsiZulu',         ['zu-ZA']],
 ['Íslenska',        ['is-IS']],
 ['Italiano',        ['it-IT', 'Italia'],
                     ['it-CH', 'Svizzera']],
 ['Magyar',          ['hu-HU']],
 ['Nederlands',      ['nl-NL']],
 ['Norsk bokmål',    ['nb-NO']],
 ['Polski',          ['pl-PL']],
 ['Português',       ['pt-BR', 'Brasil'],
                     ['pt-PT', 'Portugal']],
 ['Română',          ['ro-RO']],
 ['Slovenčina',      ['sk-SK']],
 ['Suomi',           ['fi-FI']],
 ['Svenska',         ['sv-SE']],
 ['Türkçe',          ['tr-TR']],
 ['български',       ['bg-BG']],
 ['Pусский',         ['ru-RU']],
 ['Српски',          ['sr-RS']],
 ['한국어',            ['ko-KR']],
 ['中文',             ['cmn-Hans-CN', '普通话 (中国大陆)'],
                     ['cmn-Hans-HK', '普通话 (香港)'],
                     ['cmn-Hant-TW', '中文 (台灣)'],
                     ['yue-Hant-HK', '粵語 (香港)']],
 ['日本語',           ['ja-JP']],
 ['Lingua latīna',   ['la']]];
for (var i = 0; i < langs.length; i++) {
  select_language.options[i] = new Option(langs[i][0], i);
}
select_language.selectedIndex = 29;
updateCountry();
select_dialect.selectedIndex = 0;
showInfo('info_start');
function updateCountry() {
  for (var i = select_dialect.options.length - 1; i >= 0; i--) {
    select_dialect.remove(i);
  }
  var list = langs[select_language.selectedIndex];
  for (var i = 1; i < list.length; i++) {
    select_dialect.options.add(new Option(list[i][1], list[i][0]));
  }
  select_dialect.style.visibility = list[1].length == 1 ? 'hidden' : 'visible';
}
var create_email = false;
var final_transcript = '';
var recognizing = false;
var ignore_onend;
var start_timestamp;
if (!('webkitSpeechRecognition' in window)) {
  upgrade();
} else {
  start_button.style.display = 'inline-block';
  var recognition = new webkitSpeechRecognition();
  recognition.continuous = true;
  recognition.interimResults = true;
  recognition.onstart = function() {
    recognizing = true;
    showInfo('info_speak_now');
    start_img.src = 'mic-animate.gif';
  };
  recognition.onerror = function(event) {
    if (event.error == 'no-speech') {
      start_img.src = 'mic.gif';
      showInfo('info_no_speech');
      ignore_onend = true;
    }
    if (event.error == 'audio-capture') {
      start_img.src = 'mic.gif';
      showInfo('info_no_microphone');
      ignore_onend = true;
    }
    if (event.error == 'not-allowed') {
      if (event.timeStamp - start_timestamp < 100) {
        showInfo('info_blocked');
      } else {
        showInfo('info_denied');
      }
      ignore_onend = true;
    }
  };
  recognition.onend = function() {
    recognizing = false;
    if (ignore_onend) {
      return;
    }
    start_img.src = 'mic.gif';
    if (!final_transcript) {
      showInfo('info_start');
      return;
    }
    showInfo('');
    if (window.getSelection) {
      window.getSelection().removeAllRanges();
      var range = document.createRange();
      range.selectNode(document.getElementById('final_span'));
      window.getSelection().addRange(range);
    }
    if (create_email) {
      create_email = false;
      createEmail();
    }
  };
  recognition.onresult = function(event) {
    var interim_transcript = '';
    for (var i = event.resultIndex; i < event.results.length; ++i) {
      if (event.results[i].isFinal) {
        final_transcript += event.results[i][0].transcript;
      } else {
        interim_transcript += event.results[i][0].transcript;
      }
    }
    final_transcript = capitalize(final_transcript);
    final_span.innerHTML = linebreak(final_transcript);
    interim_span.innerHTML = linebreak(interim_transcript);
    if (final_transcript || interim_transcript) {
      showButtons('inline-block');
    }
  };
}
function upgrade() {
  start_button.style.visibility = 'hidden';
  showInfo('info_upgrade');
}
var two_line = /\n\n/g;
var one_line = /\n/g;
function linebreak(s) {
  return s.replace(two_line, '<p></p>').replace(one_line, '<br>');
}
var first_char = /\S/;
function capitalize(s) {
  return s.replace(first_char, function(m) { return m.toUpperCase(); });
}
function createEmail() {
  var n = final_transcript.indexOf('\n');
  if (n < 0 || n >= 80) {
    n = 40 + final_transcript.substring(40).indexOf(' ');
  }
  var subject = encodeURI(final_transcript.substring(0, n));
  var body = encodeURI(final_transcript.substring(n + 1));
  window.location.href = 'mailto:?subject=' + subject + '&body=' + body;
}
function copyButton() {
  if (recognizing) {
    recognizing = false;
    recognition.stop();
  }
  copy_button.style.display = 'none';
  copy_info.style.display = 'inline-block';
  showInfo('');
}
function emailButton() {
  if (recognizing) {
    create_email = true;
    recognizing = false;
    recognition.stop();
  } else {
    createEmail();
  }
  email_button.style.display = 'none';
  email_info.style.display = 'inline-block';
  showInfo('');
}
function startButton(event) {
  if (recognizing) {
    recognition.stop();
    return;
  }
  final_transcript = '';
  recognition.lang = select_dialect.value;
  recognition.start();
  ignore_onend = false;
  final_span.innerHTML = '';
  interim_span.innerHTML = '';
  start_img.src = 'mic-slash.gif';
  showInfo('info_allow');
  showButtons('none');
  start_timestamp = event.timeStamp;
}
function showInfo(s) {
  if (s) {
    for (var child = info.firstChild; child; child = child.nextSibling) {
      if (child.style) {
        child.style.display = child.id == s ? 'inline' : 'none';
      }
    }
    info.style.visibility = 'visible';
  } else {
    info.style.visibility = 'hidden';
  }
}
var current_style;
function showButtons(style) {
  if (style == current_style) {
    return;
  }
  current_style = style;
  copy_button.style.display = style;
  email_button.style.display = style;
  copy_info.style.display = 'none';
  email_info.style.display = 'none';
}
</script>