Advanced User Interface Software 2000 Benchmark
Jack Zaientz
This Document: http://www.puddledock.com/cmu/auis/benchmark.html
Proposal Slides: http://www.puddledock.com/cmu/auis/proposal1.html

SMIL User Agent

Introduction

This benchmark is a simple multimedia player, or user agent, that loads and plays SMIL files and allows users to have simple control of playback. SMIL is an XML based language created by the W3C organization to allow TV-like multimedia presentations to be delivered via the WWW. SMIL’s TV-like capacities include the ability to present captions or audio over-dubs when requested by users. SMIL supports multiple concurrent video and audio files.

While there are few SMIL user agents on the market at the present time, this player resembles other multimedia players such as the RealMedia RealPlayer and Windows Multimedia Player. It will be implemented as a direct manipulation interface. As a benchmark, the SMIL User Agent will test a toolkit’s ability to parse XML documents; to display and control various media types, including images (.GIF, .JPG), text, audio (.AU, .WAV, .MP3), and video (.MPEG,.AVI); create, control and interact with objects at runtime..

Description

The SMIL User Agent may be implemented as either an applet or a stand-alone application. It should, at minimum, present a mechanism for selecting captioning and overdub preferences, a mechanism for selecting and loading a file, a multimedia content display screen, a button to play the multimedia file and a button to stop the multimedia file.

The SMIL file defines a set of screen regions and content to place in those regions and specified times to place and remove that content.  This benchmark will create and co-ordiante each screen regions seperately.  It will not use a media player (Windows Media Player, Real Player) widget to host the SMIL display, only to display relevant media types. The SMIL player will support multiple concurrent instances of each media type. 

Functional Controls

Note: Controls should exist that perform these functions. They are not required to have these names or be presented using any particular interface element.

• LOAD FILE: When a user selects and loads a SMIL file, the user agent should load file, parse out and load content files, establish sequence information and enable “Play” control.
• PLAY: When user presses the “Play” button, the user agent should begin playback of multimedia content.
• STOP: When user presses the “Stop” button, the user agent should stop playback of multimedia content.
• OPTIONS: When selected, a user is presented with a set of choices for application customization. (see below) 
• QUIT: Exits program

Preferences

• DISPLAY CAPTIONS: If text captions are available, display them.
• PLAY OVERDUBS: If audio overdubs in preferred language are available, play them.
• PREFERRED LANGUAGE: Preferred language for overdubs.
• PREFER CAPTIONS OR OVERDUBS: If both captions and overdubs are available, and user has selected both, which would the user prefer.

SMIL

SMIL, Synchronized Multimedia Integration Language, is a XML based language defined by the W3C (see http://www.w3.org/TR/REC-smil/) for the presentation of multimedia information. While SMIL is a simple language, this benchmark will only require implementation of a subset of it.

Features to be implimented include:

• Media Types: .JPG and .GIF images, .AU, .WAV, and .MP3 audio files, .AVI and .MPEG video files
• Sequential and Parallel display of regions
• Support for SWITCHing content based on preferences

• support for Cascading Style Sheets
• the Region element attribute “Fit” (it will default to hidden)
• the "A" and "Anchor" tags
• Media Types: SMIL files, Text streams
• Media Object Clip-Begin and Clip-End values

Currently there are few exiting SMIL user agents, and fewer still that implement the entire language. Existing user agents include RealPlayer, Internet Explorer 5.5, and by Soja’s Cherbourg.