Audio or Video podcasting involves creating the audio or video media you are offering, and then updating an RSS (or Atom) feed with information about your media file. RSS (version 1.0 and 2.0) and Atom are XML-based formats that are used to syndicate content as it is updated. The content could be articles, media files, video files or something completely different. Audio files should almost always be compressed in .mp3 format. If you are not targeting a specific media player, your video files should be encoded in Flash format, because nearly all players support Flash video. If you have a very specific target audience, you may choose another video format: if the iPod is your target player, the video files could be in either Quicktime or MPEG4 format, or if Microsoft Zune is your target player, you could encode them as Windows Media files. Make sure to render video to the appropriate aspect ration for your target media player).
Most RSS feeds are generated using an application, but there is no reason you couldn't update your XML file manually as you add content. If you do update the file manually, just remember that illegal XML characters need to be escaped:
& ---> &
< ---> <
> ---> >
If you have descriptive blocks of text that could contain illegal characters, you should wrap the content in
![CDATA[ ]]
indicating that it contains character data that should not be processed by the XML parser.
Here is a portion of a sample RSS file that could be used to syndicate a podcast feed. It would be linked from the page <head> region much like a CSS include:
<link href="[path-to-your-RSS-file.xml]" rel="alternate" type="application/rss+xml" title="[title-of-you-podcast]" />
The top section contains information about the feed, and the <item>...</item> sections represent each podcast. I have included example meta data for iTunes using the iTunes namespace--so any elements listed as <itunes:[tag]> represent information used specifically by iTunes and iPods.
<?xml version="1.0"?>
<rss version="2.0" xmlns:itunes="http://www.itunes.com/dtds/podcast-1.0.dtd">
<channel>
<title>My Podcasts Title</title>
<link>http://www.mysite.com/</link>
<description>A great site for ....</description>
<language>en-us</language>
<itunes:summary><![CDATA[Here is a description
that will be utilized exclusive by iTunes or and iPod]]></itunes:summary>
<itunes:subtitle>My Short Site Description</itunes:subtitle>
<itunes:keywords>Best podcasts,
[comma-separated list of relevant keywords]...</itunes:keywords>
<itunes:author>Me</itunes:author>
<itunes:owner>
<itunes:email>podcasts@mysite.com</itunes:email>
<itunes:name/>
</itunes:owner>
<itunes:category text="[Content Category]">
<itunes:category text="[Content Sub-Category]"/>
</itunes:category>
<itunes:image href="http://www.mysite.com/images/my_podcast_image.jpg"/>
<itunes:explicit>no</itunes:explicit>
<image>
<url>http://www.mysite.com/thumbnails/my_podcast_thumbnail.jpg</url>
<title>My Podcasts Title</title>
<link>http://www.mysite.com/</link>
</image>
<pubDate>Tue, 29 Aug 2008 04:00:00 GMT</pubDate>
<lastBuildDate>Tue, 29 Jul 2008 09:41:01 GMT</lastBuildDate>
<managingEditor>editor@mysite.com</managingEditor>
<webMaster>webmaster@mysite.com</webMaster>
<ttl>5</ttl>
<item>
<title>My Latest Podcast</title>
<link>http://www.mysite.com/podcasts/podcasts.html</link>
<description>Lorem ipsum dolor sit amet, consectetur
adipisicing elit, sed do eiusmod tempor incididunt ut labore
et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud
exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat.</description>
<pubDate>Tue, 29 Aug 2008 04:00:00 GMT</pubDate>
<guid>http://www.mysite.com/my_new_podcast.mp3</guid>
<itunes:summary><![CDATA[>Lorem ipsum: dolor sit amet
Consectetur adipisicing elit, sed do eiusmod tempor incididunt
ut labore et dolore magna aliqua. Ut enim ad minim veniam,
quis nostrud exercitation ullamco laboris nisi ut aliquip
ex ea commodo consequat.]]></itunes:summary>
<itunes:keywords>
[comma-separated list of relevant keywords]
</itunes:keywords>
<itunes:explicit>no</itunes:explicit>
<enclosure url="http://www.mysite.com/my_new_podcast.mp3"
length="100000" type="audio/mpeg"/>
</item>
<item>
<title>My Old Podcast</title>
<link>http://www.mysite.com/podcasts/old_podcasts.html</link>
<description>Lorem ipsum dolor sit amet, consectetur
adipisicing elit, sed do eiusmod tempor incididunt ut labore et
dolore magna aliqua. Ut enim ad minim veniam, quis nostrud
exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat.</description>
<pubDate>Tue, 29 Jul 2008 09:41:01 GMT</pubDate>
<guid>http://www.mysite.com/my_old_podcast.mp3</guid>
<itunes:summary><![CDATA[>Lorem ipsum: dolor sit amet
Consectetur adipisicing elit, sed do eiusmod tempor incididunt
ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis
nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo
consequat.]]></itunes:summary>
<itunes:keywords>
[comma-separated list of relevant keywords]
</itunes:keywords>
<itunes:explicit>no</itunes:explicit>
<enclosure url="http://www.mysite.com/my_old_podcast.mp3"
length="200340" type="audio/mpeg"/>
</item>
<item>
.
.
.
.
</channel>
</rss>