The HTML5 Video Tag's Fatal Flaw

Andrew Stephens, Thursday the 28th of May, 2009

Back in the day there was no standard way to publish video on the web This post was automatically imported from my old blog. It may look a little weird since it was not originally written for this format.. You could put any kind of video file you wanted on the server, but there was no guarantee that your readers would have the correct plugin required to view it. Everyone had to have a bunch of plugins installed to have any hope of viewing the majority of video files. This post is hideously out-of-date, but I am keeping it around due to historical interest. It actually garnered some small amount of buzz back in the day and one of the Mozilla devs dropped by my old blog to point out some issues I hadn't thought through.

Flash video solves this problem. Flash was installed on nearly every computer anyway, so once they added a video decoder it seemed obvious to provide video content in Flash, even if it was in many ways not as good as the older plugins. Flash video uses massive amounts of processor time and slows down everything else on your computer. On the other hand, websites like Flash because it is easy to skin the player to fit in with the look of the site, and it makes downloading the raw video file (slightly) more difficult.

The <video> tag is supposed to replace Flash by linking to video files in the same way that the <img> tag links to images. In practice this is more complicated than it sounds because videos typically require the ability to skip and rewind content. This means that the browser must be prepared to download different parts of the file and cache things carefully to maintain performance. But these problems have long been solved.

I have been waiting for the big sites to make announcements, and today seems to be <video> day all over the internet. Both YouTube and Dailymotion have demo pages up showing <video> content:

YouTube's HTML5 Page is designed to show how the <video> tag can replicate the functionality of their famous Flash-based player exactly. Unless you looked at the source (or your OS's process monitor) you would never know you were using a different player.

The Dailymotion HTML5 Demo is even more impressive, using the <video> tag in combination with fancy Javascript to post-process the video and extract frames.

All this is very cool, but the two demos reveal the video tag's fatal flaw : codecs. When the video tag was proposed, all browsers were supposed to support an unencumbered decoder named Ogg Theora (no seriously, that's its name). There were just three problems:

So the requirement to support Ogg Theora was dropped. This means that although all HTML5 browsers will support <video>, there is no guarantee that they will be able to play and particular file. Firefox (at least the 3.5 beta) plays Ogg Theora, but Safari plays H.264 (a superior but expensive to license codec) but not vice versa. For instance, one of the demos above plays in Firefox, the other plays in Safari. This puts us in the farcical situation of having no standard way to publish video, exactly where we started.

There is also the small point that the most widely used browser (IE) does not support the video tag, and probably won't for years. I predict that Flash video will be around for a while yet, and I am not happy about it.