- In order to create a podcast from a non-podcast feed, FeedBurner's SmartCast service examines all the links in your feed and looks for links that point to rich media (i.e., audio or video instead of plain or HTML text). The way FeedBurner does this is to make a "HEAD" request on each link. A HEAD request sends back just the information about the link instead of all the content in the link. The idea is that we can read through an entire feed, and make HEAD requests for all the links, and whenever the server sends back a message that a file is an audio or video file instead of a text file, we basically know "this is a file that we should turn into a podcast".
- The second cause of a podcast feed not working is that FeedBurner cannot retrieve the links in your source file in a timely manner, so we can't tell which files are rich media, which means we can't tell which links to put in the enclosure tag used for making podcasts. Because many of the rich media hosting sites have been overwhelmed by the popularity of podcasting, it is now sometimes taking one or two minutes for a request for a link to return the link's content type (as we pointed out in issue #1, we need the content type in order to tell which link to turn into a podcast). FeedBurner gives up if a link doesn't respond after 30 seconds, because we assume that this means the server is either down or too slow.
Nine times out of ten, when you use FeedBurner to create a podcast and we don't create podcasts for your audio links, it is because the server where you host your audio is not correctly responding to HEAD requests with the right file type. For example, the server might say that .mp3 files are "text/plain" or "text/html" instead of "audio/mpeg". This is a server configuration issue and your web server administrator needs to make this change.
Finally, the best way to see if your podcast is encountering any trouble is to regularly visit your PodMedic report, which is located on the Troubleshootize tab when viewing your feed's details within your FeedBurner account. PodMedic can tell you whether your episodes are being turned into enclosure links, and whether there are any problems with your audio or video files that prevent FeedBurner from generating a proper podcast for you.