On Thu, Jan 12, 2012 at 12:46 PM, Francis Boumphrey <boumphre...@gmail.com> wrote: > e.g. <video src='myvideo.mp4' controls> > > and my user agent does not support the format, all I get (in my versions of > Opera and Firefox) is a blank screen. No message (as I would get with > <embed>) and as far as I can see there is no way for me as an author to > know that the video is not being played so I cannot code a 'write around'.
Boris answered the rest of your questions, but here's a way to detect errors: data:text/html,<!doctype html> <video src='nonexistent.mp4' controls onerror='alert("error")'></video> If you use <source>, the error event is fired at the source element instead and doesn't bubble (why not?), so you have to put onerror on the source element instead. I don't know why UAs don't provide their own error messages, though. They provide error icons for failed image loads.