Do You Have the Time Composition and Linking in Timebased Hypermedia

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Do You Have the Time? Composition and Linking in
Time-based Hypermedia

• Lynda Hardman, Jacco van Ossenbruggen, K. Sjoerd
  Mullender, Lloyd Rutledge, and Dick C.S. Bulterman

Presented By Ananda Man Shrestha
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Introduction

• Time is dominant characteristic of multimedia
  presentations.
• Need of support for temporal (presentation time)
  and linking aspects in hypermedia.
• This paper reports new insights in the temporal
  and link activation aspects of a hypermedia
  presentation.

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Presentation Time

• Presentation artifact the reader experiences
  during the course of playing a document.
• Document underlying storage representation.
  May be single or multiple file, or stored in
  database.
• Presentation Time The timing from the
  perspective of the presentation.

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Presentation Time

• Media Element Time (intrinsic time of media
  elems.)
• The time it would take to play the media item on
  an ideal system.
• Document Time (authors perspective)
• The time the author can assign and manipulate
  within the presentation and can be stored in the
  document.
• Rendered Time (system perspective)
• Overall timing of document based upon users
  preference and system capabilities
• RunTime (readers perspective)
• Real time to play the presentation (network
  delay, reader interactions come into play)

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Media Element Time

• Has own intrinsic duration.
• E.g. Video clip, audio fragment
• SMIL Attributes clip-begin, clip-end
• (synchronized multimedia integration language)

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Document Time

• Single Media Element Object

• Author assigned duration
• E.g. Looping/stretching, cutting/ shrinking etc
• Transition information face in/out, special
  effects.
• SMIL attributes repeat, begin, end, duration.
• (synchronized multimedia integration language)
• AHM (Amsterdam hypermedia model)
• Supports atomic component duration and anchor
  duration.

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Document Time

• Multiple Media Element Object

• AHM temporal composite (atomic components
  temporal information)
• Synchronization arcs specify start time of
  destination component relative to source
  component.

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Rendered Time

• Presentation adapted to reader preference.
• Different user languages.
• Different system hardware, bandwidth etc
• Provide alternative media elements.
• Grouping of alternative components required.
• No synchronization info required among children
  of the groups.
• AHM
• Atemporal composite.

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Runtime

• 3 types of interaction at runtime.
• Interaction within a single multimedia
  presentation.
• Linking among linear multimedia presentations.
• Linking within and among non-linear multimedia
  presentations.

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Runtime

• Interaction within a single multimedia
  presentation.

• Using controls like pause/play, fast
  forward/backward
• Using predefined links. Destination anchor is in
  the same multimedia presentation.

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Runtime

• Linking among linear multimedia presentations.
• What happens to source presentation?
• Options continue, pause or replace.

• SMIL
• Show attribute replace, new and pause value.
• AHM
• Replace , new, pause option
• Link also contain activation states destination
  presentation to start in play/pause mode.

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Runtime

• Linking within and among non-linear multimedia
  presentations.

• Reading the text while playing music/video on the
  background.
• SMIL This behavior cannot be expressed.
• AHM This behavior can be expressed using
  atemporal composition.

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Discussion Session