blob: 90777f675c303f34d21c6ef4a7794d1a22e5c1a6 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
|
---
title: MediaSource.activeSourceBuffers
slug: Web/API/MediaSource/activeSourceBuffers
translation_of: Web/API/MediaSource/activeSourceBuffers
---
<div>{{APIRef("Media Source Extensions")}}{{SeeCompatTable}}</div>
<p><code><strong>activeSourceBuffers</strong></code> 是 {{domxref("MediaSource")}} 介面的唯讀屬性，回傳一個 {{domxref("SourceBufferList")}} 物件，含有在 {{domxref("SourceBuffers")}} 之中的 {{domxref("SourceBuffer")}} 物件子集合—物件的串列提供被選擇的影片軌 (video track), 啟用的音軌 (audio tracks), 以及顯示或隱藏的字軌。</p>
<h2 id="語法">語法</h2>
<pre class="brush: js">var myActiveSourceBuffers = mediaSource.activeSourceBuffers;</pre>
<h3 id="回傳值">回傳值</h3>
<p>一個 {{domxref("SourceBufferList")}} 。</p>
<h2 id="範例">範例</h2>
<p>以下的片段基於 Nick Desaulniers 所編纂的簡單範例（<a href="http://nickdesaulniers.github.io/netfix/demo/bufferAll.html">觀看實際演示</a>，或者<a href="https://github.com/nickdesaulniers/netfix/blob/gh-pages/demo/bufferAll.html">下載原始碼</a> 以利更進一步研究。）</p>
<pre class="brush: js language-js"><code class="language-js"><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">;
console.log(mediaSource.activeSourceBuffers);
// will contain the source buffer that was added above,
// as it is selected for playing in the video player</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="規格">規格</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">規格</th>
<th scope="col">狀態</th>
<th scope="col">注釋</th>
</tr>
<tr>
<td>{{SpecName('Media Source Extensions', '#widl-MediaSource-activeSourceBuffers', 'activeSourceBuffers')}}</td>
<td>{{Spec2('Media Source Extensions')}}</td>
<td>Initial definition.</td>
</tr>
</tbody>
</table>
<h2 id="相容性表格">相容性表格</h2>
<div>{{CompatibilityTable}}</div>
<div id="compat-desktop">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Chrome</th>
<th>Edge</th>
<th>Firefox (Gecko)</th>
<th>Internet Explorer</th>
<th>Opera</th>
<th>Safari (WebKit)</th>
</tr>
<tr>
<td>Basic support</td>
<td>23</td>
<td>{{CompatVersionUnknown}}</td>
<td>{{CompatGeckoDesktop("25.0")}}<sup>[1]</sup><br>
{{CompatGeckoDesktop("42.0")}}</td>
<td>11<sup>[2]</sup></td>
<td>15</td>
<td>8</td>
</tr>
</tbody>
</table>
</div>
<div id="compat-mobile">
<table class="compat-table">
<tbody>
<tr>
<th>Feature</th>
<th>Android</th>
<th>Edge</th>
<th>Firefox Mobile (Gecko)</th>
<th>Firefox OS (Gecko)</th>
<th>IE Phone</th>
<th>Opera Mobile</th>
<th>Safari Mobile</th>
</tr>
<tr>
<td>Basic support</td>
<td>4.4.4</td>
<td>{{CompatVersionUnknown}}</td>
<td>
<p>{{CompatNo}}</p>
</td>
<td>{{CompatNo}}</td>
<td>11</td>
<td>30</td>
<td>{{CompatNo}}</td>
</tr>
</tbody>
</table>
</div>
<p>[1] 在切換 about:config 偏好設定 media.mediasource.enabled 為 true 時可以使用。此外，支援只限於白名單內的網站，如：YouTube, Netflix, 以及其他熱門的串流網站。白名單已經被移除且 Media Source Extensions 在 42+ 對所有網站已預設為啟用。</p>
<p>[2] 只在 Windows 8+ 上有效。</p>
<h2 id="相關資料">相關資料</h2>
<ul>
<li>{{domxref("SourceBuffer")}}</li>
<li>{{domxref("SourceBufferList")}}</li>
</ul>
|
