mFeeds

As this Podcasting thing continues to move forward, many of us have decided that we would look forward to solutions that will enable us to enjoy them, but at our leisure. Well one solution to taking a Web page that has Podcasts or other audio content is mFeeds. This service will take your requested page and then generate it into a Podcast friendly RSS feed for you to enjoy!

How does it work?

MFeeds works by scanning the link, description, and content:encoded portions of the RSS searching for links to media files. Any links found are then added as enclosures for that item.

What versions of RSS are supported?

Currently, MFeeds supports RSS versions 0.91, 0.92, 2.0, and 1.0. The Atom format is not supported because it does not have official support for enclosures yet.

Wondering about all those versions? Read Mark Pilgrim’s, The Myth of RSS Compatibility.

How does it work? And I want the technical details!

MFeeds is written in Perl and uses LWP::UserAgent, XML::Twig, and HTML::PullParser for fetching feeds and parsing the RSS and HTML. HTTP::Cache and Cache::FileCache are used to cache the HTTP requests and RSS.

Links with an extension below are pulled from the description, link, and content:encoded tags in each RSS item. An HTTP HEAD request is sent for each link to discover the Content-Length and Content-Type of each file, and using this information, enclosures for each link are generated and added to the document.

Extensions: mp3 ogg mov torrent m4a m4p mp4 mpeg mpg qt avi wav aiff aif mid midi au wmv wma shn flac m3u rm ram

Using the extension of a file as a base is not the most reliable method, but it works nearly all of the time and cuts down significantly the number of links the script has to check (consider how many links weblog posts have!).

Note that if the HTTP HEAD request fails, the link won’t be included in the RSS.

What are the future plans?

Support for adding enclosures to Atom feeds is planned as soon as a standard is found. Another feature to be added will be media feed generation in a number of RSS versions instead of just 0.92.