HTML and CSS Reference
In-Depth Information
Theora + Vorbis = .ogg
Theora ( ) is an open source, free video codec developed by Vorbis ( ) is a free, open source audio codec that is used
in conjunction with Theora. Both Theora and Vorbis are stored in an .ogg file. .ogg files
have the broadest support among traditional web browsers, but, unfortunately, not on
handheld devices. Many commercial companies (e.g., Apple) have balked at using
Theora/Vorbis because they are unsure whether somewhere, someplace, someone
might own a patent that covers part of the technology, and thus they might get sued
for using it.
Sometimes technology companies get hit with what is known as a sub-
marine patent . This was a patent tactic—available up until 1995 in the
U.S.—that allowed a filer to delay the publication of a patent. Because
patents were only enforceable for 17 years, if someone filed one but
delayed the publications, he could wait years (even decades) until some-
one else came up with the same idea, then hit that person with a lawsuit.
H.264 + $$$ = .mp4
H.264 is a high-quality video standard that has received the backing of some very big
players, such as Apple, Adobe, and Microsoft. However, despite offering high-quality
video, it only defines a standard—not a video codec. An organization named MPEG
LA owns the intellectual property, and they license it out to software and hardware
vendors. Many companies that have implemented H.264 have done so with their own
proprietary codecs. As a result, the varying codecs are incompatible with one another,
making this a tricky format to use across multiple platforms. H.264 videos have
the .mp4 extension. Most for-profit corporations have implemented support for this
format on their platforms, but the developers of open source browsers like Firefox and
Opera have not. In late 2010, Google dropped H.264 support in Chrome in favor of
VP8 + Vorbis = .webm
WebM is a new open source video standard supported by Google, Adobe, Mozilla, and
Opera. It is based on the VP8 codec and includes Vorbis (just like Theora) as an audio
codec. When announced they had converted many of their videos to be
HTML5-compatible, one of the formats they used was WebM. Currently, only Google
Chrome and Opera support WebM, but broader support should be coming in the
Search WWH ::

Custom Search