Native Video - HTML5 - page 115

Note that providing fallback content is not the same as ensuring acces-
sibility or providing accessible content.
Fallback content is content that displays on browsers that don't support
video . It does two things: informs the user that her browser doesn't
support HTML5 video and provides a link to download the video.
For a good overview of the state of HTML5 video accessibility, see http:
//john.foliot.ca/accessibility-and-html5-today/ .
Along with different video formats, Flash video can be inserted as a fallback alternative.
In fact, you can nest fallback content for lack of support for both the object and
video elements:
<video src="video.ogv" controls>
<object type="application/x-shockwave-flash"
data="player.swf?file="video.mp4">
<param name="movie" value="player.swf?file="video.mp4">
<a href="video.mp4">Download the Learning to Love HTML5
introductory video</a>
</object>
</video>
Discussion
Unfortunately, video is not as straightforward to implement as it might seem, because
not all browsers support the same set of video file formats.
Multiple video codecs
As with audio (see Recipe 4.1 ), the HTML5 specification doesn't specify which video
codecs should be supported.
Instead, the browser makers decide which format to support (see Table 5-1 ). This is
fine, but getting browser vendors to agree on any one thing is nearly impossible. Getting
them to agree on which video formats—much less a single video format—to support
is going to be next to impossible. To work around this situation, video needs to be
encoded and published in multiple formats in order to display across the broadest range
of browsers.
While the blink element is almost universally disliked, it's still suppor-
ted in browsers. Go figure.