Responsive HTML5 video and iFrames

We have seen that, as ever, supporting older browsers leads to code bloat. What began with the <video> tag being one or two lines ended up being 10 or more lines (and an extra Flash file) just to make older versions of Internet Explorer happy! For my own part, I'm usually happy to forego the Flash fallback in pursuit of a smaller code footprint but each use-case differs.

Now, the only problem with our lovely HTML5 video implementation is it's not responsive. That's right, an example in a responsive web design with HTML5 and CSS3 book that doesn't 'respond'.

Thankfully, for HTML5 embedded video, the fix is easy. Simply remove any height and width attributes in the markup (for example, remove width="640" height="480") and add the following in the CSS:

video { max-width: 100%; height: auto; }

However, while that works fine for files that we might be hosting locally, it doesn't solve the problem of videos embedded within an iFrame (take a bow YouTube, Vimeo...