More information about SMIL

“Although MPEG (Moving Picture Experts Group) also looks at content and coding, SMIL is more web-centric unlike MPEG, which is more media centric and involves more than just content and coding. A close comparison would be D-HTML (dynamic hypertext markup language). However, D-HTML uses scripted definitions of local behaviours, without a notion of the presentation’s context. Actions such as timed events are therefore difficult to co-ordinate.

Then there are W3C technologies such as cascading style sheets (CSS) which are compatible with SMIL, which means CSS can be created for media-based SMIL, with CSS code complementing SMIL layout. So why not simply use CSS?

There is a difference between CSS’s text-flow and SMIL’s time-flow documents. Although the XML nesting tells a lot about text layout, it tells very little about temporal layout, which is what SMIL is good for. The non-modularised nature of CSS also induces too much overhead and there are conceptual limitations to CSS for time-based presentations.

SMIL, on the other hand, is basically an XML document with defined XML DTD (document type definition) and schema. It is a declarative, integration language with the media elements referred to and not included. This allows SMIL documents to be hand-authored, though probably few would try since there are already many tools available, such as an SMIL authoring tool known as Fluition and RealNetwork’s RealProducer G2 Authoring Kit.”

Read the full article from Deaf Today.