CELF Audio Video Graphics specification v2.0
The AVGWG charter includes interface standardization: "No single default/standard interfaces exist for AVG. Having a well defined, well supported interface for AVG devices will reduce fragmentation of solutions and encourage the CE community to develop solutions that apply to conforming interfaces, so that they can be deployed across a wider range of systems." The CELF 1.0 specification contained recommendations on graphics, but hardly any on audio/video. So version 2.0 should improve on this!
Process & Planning
The specification is being defined by the AVG core group, i.e. people actively contributing to one or more of the group activities. We started with gathering requirements and proposals. Based on these inputs the draft CELF AVG specification was created. The AVG working group has reviewed and reworked the specification, and finally the specification has been ratificatied by the CELF Architecture Group and Board of Directors. Feedback on this specification is appreciated, e.g. via the CELF developers mailing list email@example.com. This version of the CELF AVG specification is mostly targetted at the DTV/STB domain, extensions for the mobile phone domain are being worked on as a next step.
Since there are already many APIs for Audio/Video/Graphics we did not create new APIs. Instead, we reference a number of (already well known) APIs. In a single picture, the specification looks like this:
The DirectFB specification at http://www.directfb.org
The OpenGL ES specification at http://www.khronos.org/opengles/spec/
The official site of the UHAPI specifications, at http://www.uhapi.org
UHAPI specification version 1.1 version, donated by the UHAPI Forum to CELF at http://tree.celinuxforum.org/pubwiki/moin.cgi/UHAPI
UHAPI4Linux open source implementation of UHAPI interfaces: http://sourceforge.net/projects/uhapi4linux/