HTML and CSS Reference
Each of these (and many other) container formats are capable of supporting multiple codecs . A
codec is a compression/decompression algorithm for creating the highest quality video at the low-
est possible file size. The most frequently used codecs include H.264, often used for high-definition
video; VP8, a relatively new codec released into the public domain by Google; and Theora, created
by Xiph to work with its Ogg container.
To play video on the Web, the video file must be encoded in a particular format and codec.
Numerous desktop tools for encoding video are available, including Adobe CS5 Media Encoder
(Figure 25-1), which is bundled with Flash Professional CS5. As you might expect, the online
video explosion has also brought about a plethora of online video encoding services, like the one
If you're looking to encode your video in the newer formats — Ogg and
WebM — and are a Firefox user, there's a free plug-in available called Firefogg
video and choose from a number of presets with a variety of compression ranges
and configurable options. The length of the actual encoding process depends on
the duration of your video and conversion choices, but the service seems quite
quick in general.