One Problem with HTML Video
July 3rd, 2009
The HTML 5 video element is a move in the right direction, but it currently doesn’t work in Google Reader. Here is how a YouTube video looks in Reader:

This is on a Mac, using Firefox 3.5. Here is a blog containing the new HTML 5 video tag:

When I go to that blog, it works…just not in Reader.
I suppose the Google Reader team will fix this soon. As soon as HTML5 video gets used a lot.
I’d imagine that they have a whitelist of tags that they allow through in reader. Anything else is quite insecure…
That problem probably probably isn’t’ Google reader, its probably that blog. I think they’re using user agent matching and if the user agent doesn’t say Firefox 3.5 or chrome (or safari?) it presents a different page. Google’s server fetches the feed, then in Google reader, you look at the copy of the feed Google got instead of getting a new one. This page shows what Reader’s user agent looks like http://www.google.com/help/reader/publishers.html#faq
Asa is definitely right. That blog is presenting a different version of the feed to reader than it’d give to firefox.