導入 HTML5 音訊標記的快速指南

Ernest Delgado
Ernest Delgado

步驟 1:使用音訊標記包裝 Flash 物件

無法辨識音訊標記的瀏覽器會改為載入 Flash 內容。

 <audio>
    <object class="playerpreview" type="application/x-shockwave-flash"
            data="player_mp3_mini.swf" width="200" height="20">
      <param name="movie" value="player_mp3_mini.swf" />
      <param name="bgcolor" value="#085c68" />
      <param name="FlashVars" value="mp3=test.mp3" />
      <embed href="player_mp3_mini.swf" bgcolor="#085c68" width="200"
             height="20" name="movie" align=""
             type="application/x-shockwave-flash" flashvars="mp3=test.mp3">
      </embed>
    </object>
</audio>

步驟 2:新增來源參考資料

我們可以視需要新增任意數量的「來源」行和格式。如果瀏覽器不支援某種特定格式,就會改用下一個格式,以此類推。

 <audio>
  <source src="test.mp3" type="audio/mpeg" />
  <source src="test.ogg" type="audio/ogg" />

  <object class="playerpreview" type="application/x-shockwave-flash"
          data="player_mp3_mini.swf" width="200" height="20">
    <param name="movie" value="player_mp3_mini.swf" />
    <param name="bgcolor" value="#085c68" />
    <param name="FlashVars" value="mp3=test.mp3" />
    <embed href="player_mp3_mini.swf" bgcolor="#085c68" width="200"
           height="20" name="movie" align=""
           type="application/x-shockwave-flash" flashvars="mp3=test.mp3">
    </embed>
  </object>
</audio>

步驟 3:在 Flash 中新增備用方案

為求安全起見,我們需要為 Flash 音訊播放器新增備用方案,以防瀏覽器不支援我們指定的任何格式。舉例來說,Firefox 3.5 只支援 Ogg 格式的音訊標記,但我們可能只有 mp3 檔案。

<audio>
  <source src="test.mp3" type="audio/mpeg" />
  <object class="playerpreview" type="application/x-shockwave-flash"
          data="player_mp3_mini.swf" width="200" height="20">
    <param name="movie" value="player_mp3_mini.swf" />
    <param name="bgcolor" value="#085c68" />
    <param name="FlashVars" value="mp3=test.mp3" />
    <embed href="player_mp3_mini.swf" bgcolor="#085c68" width="200"
           height="20" name="movie" align=""
           type="application/x-shockwave-flash" flashvars="mp3=test.mp3">
    </embed>
  </object>
</audio>

<div id="player_fallback"></div>
<script type="application/javascript">
  if (document.createElement('audio').canPlayType) {
    if (!document.createElement('audio').canPlayType('audio/mpeg')) {
      swfobject.embedSWF(
        "player_mp3_mini.swf",
        "player_fallback",
        "200",
        "20",
        "9.0.0",
        "",
        {"mp3":"test.mp3"},
        {"bgcolor":"#085c68"});
    }
  }
</script>

為簡化操作,我們使用 SWFObject 程式庫,透過 JavaScript 插入 Flash 播放器。如要加入這個程式庫,只要使用 Google AJAX Libraries API,並在標頭中插入這兩行程式碼即可:

<script src="http://www.google.com/jsapi" type="application/javascript"></script>
<script type="application/javascript">google.load("swfobject", "2.2");</script>

步驟 4:新增預設控制項以顯示播放器

這些控制項無法自訂 (請參閱結尾的範例)。由於這些預設控制項會無論支援的格式為何都顯示,因此我們需要使用先前建立的條件來處理其顯示權限。

<audio id="audio_with_controls" controls="controls">
  <source src="test.mp3" type="audio/mpeg" />
  <object class="playerpreview" type="application/x-shockwave-flash"
          data="player_mp3_mini.swf" width="200" height="20">
    <param name="movie" value="player_mp3_mini.swf" />
    <param name="bgcolor" value="#085c68" />
    <param name="FlashVars" value="mp3=test.mp3" />
    <embed href="player_mp3_mini.swf" bgcolor="#085c68" width="200"
           height="20" name="movie" align=""
           type="application/x-shockwave-flash" flashvars="mp3=test.mp3">
    </embed>
  </object>
</audio>

<div id="player_fallback"></div>
<script type="application/javascript">
  if (document.createElement('audio').canPlayType) {
    if (!document.createElement('audio').canPlayType('audio/mpeg')) {
      ... SWFObject script line here ...
      document.getElementsById('audio_with_controls').style.display = 'none';
    }
  }
</script>

或者,您也可以使用 JavaScript 和 CSS 建立自己的播放器。

<audio id="audio">
  <source src="test.mp3" type="audio/mpeg" />
  <object class="playerpreview" type="application/x-shockwave-flash"
          data="player_mp3_mini.swf" width="200" height="20">
    <param name="movie" value="player_mp3_mini.swf" />
    <param name="bgcolor" value="#085c68" />
    <param name="FlashVars" value="mp3=test.mp3" />
    <embed href="player_mp3_mini.swf" bgcolor="#085c68" width="200"
           height="20" name="movie" align=""
           type="application/x-shockwave-flash" flashvars="mp3=test.mp3">
    </embed>
  </object>
</audio>

<div id="player_fallback"></div>
<div id="player" style="display: none">
  <button onClick="document.getElementById('audio').play()">Play</button>
  <button onClick="document.getElementById('audio').pause()">Pause</button>
</div>

<script type="application/javascript">
  if (document.createElement('audio').canPlayType) {
    if (!document.createElement('audio').canPlayType('audio/mpeg')) {
      ... SWFObject script lines here ...
    } else { // HTML5 audio + mp3 support
      document.getElementById('player').style.display = 'block';
    }
  }
</script>