Codec Roundup

Perhaps the most confusing aspect of online video is the formats to use.

Here is a quick roundup of those currently available:

H.264 - also called 'MPEG4 and 'MP4'. This is a very long standing standard that has recently become de facto for the delivery of on demand content over the internet. It is a codec (MP4 is a 'wrapper' or 'format' and can also be played in other formats such as .FLV, MOV and even .WMV), and has good encoding, especially at high data rates. There are other advantages: this is the only format Google currently indexes (although they have recently announced that they will not play this format in future releases of their Chrome browser in order to favour their own 'WebM' codec). This format plays on iPads and iPhones and can be made to play on Android devices. It is also now largely supported by IPTV devices such as set top boxes. Overall, it is by far and away the best codec to use if you want widespread distribution. The downside is that it is 'owned' by a consortium of very large companies, although they recently agreed to make it freely available to all but the largest commercial users.

H.263, also called 3GP, is a codec that was developed for mobile devices. It is still used on older phones and on platforms supported by Blackberry and Nokia.

Ogg Theora - is a very old and largely unloved codec that is 'open source'. The quality is poor and support is patchy at best.

WebM - In 2009 Google purchased a company called On2, who were responsible for the codec at the core of the delivery of most Flash video (FLV). These codecs carry the VPx lable and VP6 and VP7 are what you will largely find as the formats of most current videos on the web. However, these are quickly being deprecated to H.264 (see above) and to VP8, or WebM, which is a codec that Google has ostensibly 'open sourced', but which is almost totally unsupported at the moment by anyone else.

VPx - On2 was the company that developed the core codecs used by Adobe Flash and as such has had a core role in the development of video over the internet. On2 was acquired by Google in 2009 and its codecs are no longer supported, although widely used.

VC1 - this is the core codec developed by Microsoft, and was, for a long time very popular since it was the only codec that came with a digital rights management specification. When Microsoft went on to develop the Silverlight development platform it deprecated VC1 and now sees H.264 as its core codec.

There are a number of other, largely proprietary, codecs available, for example those from Move Networks, whose assets were recently sold EchoStar, but none have achieved mainstream adoption.