Actually the feed made available for videos and photos have a different structure. For photos, the feed item includes also information about the enclosure, that is the photo itself is attached to the feed item, via the enclosure tag. This way, for a photo, the file link could be converted in a link appended to the end of the item description, when the feed is processed in some feed pipe. This is not for videos: here information about the video link is in the summary tag and content tag, but it's not precessable.
The following is an example of video feed item:
span class="start-tag">entry>
span class="start-tag">title>Il punto di vista di Lawrence Lessig sulla giornata di oggi e sul nostro Paese</
title>
span class="start-tag">link
rel=
"alternate" href="http://ecosistema20.ning.com/xn/detail/2951950:Video:5228"/>
span class="start-tag">id>tag:ecosistema20.ning.com,2010-03-12:2951950:Video:5228</
id>
span class="start-tag">updated>2010-03-12T09:50:20.228Z</
updated>
span class="start-tag">author>span class="start-tag">name>Ecosistema 2.0</
name></
author>
span class="start-tag">summary
type=
"html">&
lt;a href=&
quot;http://ecosistema20.ning.com/video/il-punto-di-vista-di-lawrence&;
quot;&
gt;&
lt;br /&
gt; &
lt;img src=&
quot;http://api.ning.com:80/files/TQDVvdVztQK*ErpNpOy2V4ZbFbkcuryWovQ-EGf*q8BrZDZJgovUR9ADnesHXjR8Cxm3K15-7tHqU*pOfzL4NYyGrFZpbJMC/857194876.jpeg?width=240&
amp;amp;height=180&
quot; width=&
quot;240&
quot; height=&
quot;180&
quot; alt=&
quot;Anteprima&
quot; /&
gt;&
lt;br /&
gt; &
lt;/a&
gt;&
lt;br /&
gt;Internet e&
#039; liberta&
#039;, 11 mar 2010 -&
lt;br /&
gt;Roma, Palazzo di Montecitorio, Sala della Regina - CapitaleDigitale</
summary>
span class="start-tag">content
type=
"html">&
lt;a href=&
quot;http://ecosistema20.ning.com/video/il-punto-di-vista-di-lawrence&;
quot;&
gt;&
lt;br /&
gt; &
lt;img src=&
quot;http://api.ning.com:80/files/TQDVvdVztQK*ErpNpOy2V4ZbFbkcuryWovQ-EGf*q8BrZDZJgovUR9ADnesHXjR8Cxm3K15-7tHqU*pOfzL4NYyGrFZpbJMC/857194876.jpeg?width=240&
amp;amp;height=180&
quot; width=&
quot;240&
quot; height=&
quot;180&
quot; alt=&
quot;Anteprima&
quot; /&
gt;&
lt;br /&
gt; &
lt;/a&
gt;&
lt;br /&
gt;Internet e&
#039; liberta&
#039;, 11 mar 2010 -&
lt;br /&
gt;Roma, Palazzo di Montecitorio, Sala della Regina - CapitaleDigitale</
content>
</
entry>
and this is an example of photo feed item:
span class="start-tag">item>
span class="start-tag">guid>2951950:Photo:5162</
guid>
span class="start-tag">title>venezia2020_250X100a</
title>
span class="start-tag">link>
http://ecosistema20.ning.com/photo/venezia2020250x100a-1</link>
span class="start-tag">description>...</
description>
span class="start-tag">pubDate>Thu, 11 Mar 2010 19:13:37 +0000</
pubDate>
span class="start-tag">enclosure
url=
"http://api.ning.com:80/files/Ww5Jn9Xw6RZHo-G3kofd2f7g33FABu-ZEkS6Aw...*V3eI0QoOQv3D6YjKyf9mzwYr*p-BT/venezia2020_250X100a.jpg?width=250&height=100" type=
"image/jpeg" length=
"1" />
span class="start-tag">media:content
url=
"http://api.ning.com:80/files/Ww5Jn9Xw6RZHo-G3kofd2f7g33FABu-ZEkS6Aw...*V3eI0QoOQv3D6YjKyf9mzwYr*p-BT/venezia2020_250X100a.jpg?width=250&height=100" type=
"image/jpeg" height=
"" width=
""/>
span class="start-tag">media:description>Olimpiadi Venezia 2020</
media:description>
span class="start-tag">media:thumbnail
url=
"http://api.ning.com:80/files/Ww5Jn9Xw6RZHo-G3kofd2f7g33FABu-ZEkS6Aw...*V3eI0QoOQv3D6YjKyf9mzwYr*p-BT/venezia2020_250X100a.jpg?width=240&height=96" width=
"240" height=
"96" />
span class="start-tag">media:keywords></
media:keywords>
span class="start-tag">media:credit
role=
"photographer">Ecosistema 2.0</
media:credit>
</
item>
To see a consequence, look how the two feed items are imported in twitter, via twitterfeed:
<item>
<title>ecosistema20: [Video] Il punto di vista di Lawrence Lessig sulla giornata di oggi e sul nostro Paese</title>
<description>ecosistema20: [Video] Il punto di vista di Lawrence Lessig sulla giornata di oggi e sul nostro Paese</description>
<pubDate>Fri, 12 Mar 2010 10:39:24 +0000</pubDate>
<guid>
http://twitter.com/ecosistema20/statuses/10366509786</guid>;
<link>
http://twitter.com/ecosistema20/statuses/10366509786</link>;
</item>
and
<item>
<title>ecosistema20: [Photo] venezia2020_250X100a
http://bit.ly/cSKC4I</title>
<description>ecosistema20: [Photo] venezia2020_250X100a
http://bit.ly/cSKC4I</description>;
<pubDate>Thu, 11 Mar 2010 19:35:20 +0000</pubDate>
<guid>
http://twitter.com/ecosistema20/statuses/10336394563</guid>;
<link>
http://twitter.com/ecosistema20/statuses/10336394563</link>;
</item>
In the photo example, you can see the photo link:
http://bit.ly/cSKC4Ihas been appended to the title and description. This is not done for the video entry, so people who reads the twitter message cannot access the video clicking somewhere in the twitter message itself.