Example content: https://support.jwplayer.com/customer/portal/articles/1406722-rss-playlist-embed

When using Video Downloadhelper (Firefox), the detection of all video's within the playlist, is going gradually during playtime.
Is it possible to detect all video's in the XML playlist at once, and download them at start?

Example playlist from other site:

<rss xmlns:media="http://search.yahoo.com/mrss/" xmlns:jwplayer="http://developer.longtailvideo.com/trac/" version="2.0">
<channel>
<title>MRSS Playlist Playlist</title>
<item>
<title>Big Buck Bunny</title>
<media:content url="/members/VIP14febDeel1.mp4"/>
<media:thumbnail url="/members/snapshot14022017.jpg"/>
<description>B.</description>
<jwplayer:duration/>
</item>
<item>
<title>Elephant's Dream</title>
<media:content url="/members/VIP14febDeel2.mp4"/>
<description>E</description>
<jwplayer:duration/>
</item>
<item>
<title>Elephant's Dream</title>
<media:content url="/members/VIP14febDeel3.mp4"/>
<description>E</description>
<jwplayer:duration/>
</item>
<item>
<title>Elephant's Dream</title>
<media:content url="/members/VIP14febDeel4.mp4"/>
<description>E</description>
<jwplayer:duration/>
</item>
</channel>
</rss>

Regards,
Chris