Here is a setup of the captions plugin in combination with a playlist:
Here is a printout of the RSS playlist:
<rss version="2.0"
xmlns:jwplayer="http://developer.longtailvideo.com/trac/wiki/FlashFormats">
<channel>
<title>Example playlist with captions</title>
<item>
<title>Men With Talent</title>
<description>This entry does not have any captions.</description>
<jwplayer:file>/assets/talent.mp4</jwplayer:file>
<jwplayer:image>/assets/talent.jpg</jwplayer:image>
</item>
<item>
<title>Coronation Street</title>
<description>This entry has a single caption track.</description>
<jwplayer:file>/assets/corrie.mp4</jwplayer:file>
<jwplayer:image>/assets/corrie.jpg</jwplayer:image>
<jwplayer:captions.file>/assets/corrie.txt</jwplayer:captions.file>
</item>
<item>
<title>Big Buck Bunny</title>
<description>This entry has two captions tracks.</description>
<jwplayer:file>/assets/bunny.mp4</jwplayer:file>
<jwplayer:image>/assets/bunny.jpg</jwplayer:image>
<jwplayer:captions.files>/assets/bunny_en.txt,/assets/bunny_nl.txt</jwplayer:captions.files>
<jwplayer:captions.labels>English,Nederlands</jwplayer:captions.labels>
</item>
</channel>
</rss>
The playlist is in RSS format and uses the jwplayer: extension to display the captions options.
Note that both the playlist and the captions are subject to crossdomain loading restrictions.