---
title: MediaSource.readyState
slug: Web/API/MediaSource/readyState
tags:
- API
- Audio
- Experimental
- MSE
- Media Source Extensions
- MediaSource
- Property
- Reference
- Video
- readyState
translation_of: Web/API/MediaSource/readyState
---
<div>{{APIRef("Media Source Extensions")}}{{SeeCompatTable}}</div>
<p><span class="seoSummary">{{domxref("MediaSource")}} インターフェイスの <strong><code>readyState</code></strong> 読み取り専用プロパティは、現在の <code>MediaSource</code> の状態を表す列挙を返します。</span> 3つの可能な値は次のとおりです。</p>
<ul>
<li><code>closed</code>: ソースは現在メディア要素にアタッチされていません。</li>
<li><code>open</code>: ソースはメディア要素にアタッチされ、{{domxref("SourceBuffer")}} オブジェクトを受信する準備ができています。</li>
<li><code>ended</code>: ソースはメディア要素にアタッチされていますが、{{domxref("MediaSource.endOfStream()")}} の呼び出しを介してストリームが終了しています。</li>
</ul>
<h2 id="Syntax" name="Syntax">構文</h2>
<pre class="syntaxbox">var <em>myReadyState</em> = <em>mediaSource</em>.readyState;</pre>
<h3 id="Value" name="Value">値</h3>
<p>{{domxref("DOMString")}}。</p>
<h2 id="Example" name="Example">例</h2>
<p>次のスニペットは、Nick Desaulniers によって書かれた簡単な例からのものです（<a href="http://nickdesaulniers.github.io/netfix/demo/bufferAll.html">ライブで完全なデモを見る</a>か、<a href="https://github.com/nickdesaulniers/netfix/blob/gh-pages/demo/bufferAll.html">ソースをダウンロード</a>してさらに調査してください）。</p>
<pre class="brush: js language-js"><code class="language-js"><span class="keyword token">if</span> <span class="punctuation token">(</span><span class="string token">'MediaSource'</span> <span class="keyword token">in</span> window <span class="operator token">&&</span> MediaSource<span class="punctuation token">.</span><span class="function token">isTypeSupported<span class="punctuation token">(</span></span>mimeCodec<span class="punctuation token">)</span><span class="punctuation token">)</span> <span class="punctuation token">{</span>
<span class="keyword token">var</span> mediaSource <span class="operator token">=</span> <span class="keyword token">new</span> <span class="class-name token">MediaSource</span><span class="punctuation token">;</span>
<span class="comment token"> //console.log(mediaSource.readyState); // closed
</span> video<span class="punctuation token">.</span>src <span class="operator token">=</span> URL<span class="punctuation token">.</span><span class="function token">createObjectURL<span class="punctuation token">(</span></span>mediaSource<span class="punctuation token">)</span><span class="punctuation token">;</span>
mediaSource<span class="punctuation token">.</span><span class="function token">addEventListener<span class="punctuation token">(</span></span><span class="string token">'sourceopen'</span><span class="punctuation token">,</span> sourceOpen<span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="punctuation token">}</span> <span class="keyword token">else</span> <span class="punctuation token">{</span>
console<span class="punctuation token">.</span><span class="function token">error<span class="punctuation token">(</span></span><span class="string token">'サポートされていない MIME タイプまたはコーデック: '</span><span class="punctuation token">,</span> mimeCodec<span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="punctuation token">}</span>
<span class="keyword token">function</span> sourceOpen <span class="punctuation token">(</span>_<span class="punctuation token">)</span> <span class="punctuation token">{</span>
<span class="comment token"> //console.log(this.readyState); // open
</span> <span class="keyword token">var</span> mediaSource <span class="operator token">=</span> <span class="keyword token">this</span><span class="punctuation token">;</span>
<span class="keyword token">var</span> sourceBuffer <span class="operator token">=</span> mediaSource<span class="punctuation token">.</span><span class="function token">addSourceBuffer<span class="punctuation token">(</span></span>mimeCodec<span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="function token">fetchAB<span class="punctuation token">(</span></span>assetURL<span class="punctuation token">,</span> <span class="keyword token">function</span> <span class="punctuation token">(</span>buf<span class="punctuation token">)</span> <span class="punctuation token">{</span>
sourceBuffer<span class="punctuation token">.</span><span class="function token">addEventListener<span class="punctuation token">(</span></span><span class="string token">'updateend'</span><span class="punctuation token">,</span> <span class="keyword token">function</span> <span class="punctuation token">(</span>_<span class="punctuation token">)</span> <span class="punctuation token">{</span>
mediaSource<span class="punctuation token">.</span><span class="function token">endOfStream<span class="punctuation token">(</span></span><span class="punctuation token">)</span><span class="punctuation token">;</span>
video<span class="punctuation token">.</span><span class="function token">play<span class="punctuation token">(</span></span><span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="comment token"> //console.log(mediaSource.readyState); // ended
</span> <span class="punctuation token">}</span><span class="punctuation token">)</span><span class="punctuation token">;</span>
sourceBuffer<span class="punctuation token">.</span><span class="function token">appendBuffer<span class="punctuation token">(</span></span>buf<span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="punctuation token">}</span><span class="punctuation token">)</span><span class="punctuation token">;</span>
<span class="punctuation token">}</span><span class="punctuation token">;</span></code></pre>
<h2 id="Specifications" name="Specifications">仕様</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">仕様</th>
<th scope="col">状態</th>
<th scope="col">コメント</th>
</tr>
<tr>
<td>{{SpecName('Media Source Extensions', '#idl-def-mediasource-readystate', 'readyState')}}</td>
<td>{{Spec2('Media Source Extensions')}}</td>
<td>初期定義</td>
</tr>
</tbody>
</table>
<h2 id="Browser_compatibility" name="Browser_compatibility">ブラウザーの互換性</h2>
<div>
<p>{{Compat("api.MediaSource.readyState")}}</p>
</div>
<h2 id="See_also" name="See_also">関連情報</h2>
<ul>
<li>{{domxref("SourceBuffer")}}</li>
<li>{{domxref("SourceBufferList")}}</li>
</ul>