CS4624 Text - Ch 14

Multimedia Interchange

14

• interchange files or real-time
• needs to reference interobjects, compose, access/present
• evaluation of models

• application contexts: create and edit documents, delivery of final form, delivery in real-time over network, interapplication exchange
• interchange modes: applications use an API (interchange or distributed object), media servers, storage (file or DBMS), network with time constraints
• technical issues: data model, scripting, efficiency (storage, access), portability, extensibility

• Abstract atom model: movie atom (movie time scale and display) - track atom (temporal and spatial composite) - media atom (physical attributes and access methods)- [media header, handle ref. atom (interpreter of data), media info. atom (organization of media storage), user-defined data atom (privately defined data)]
• Track model: movie with several tracks, track with media atoms, mapping of group of atoms to physical media

• movie fragment with: movie atom, track atom, media atom (sound clip of 4K samples at 600/sec)

• Object Media Framework - industry standardization accepted by IMA
• enhances track model: identifies source materials, has compositional objects and class hierarchy
• other features: special track types like Time Code, special effects/transitions allowing overlaps, motion control (time warp subtree) per track relative to that of another (ratio)

• final-form representation allowing real-time and interactive use over networks, with statial and temporal relationships, but with logical model omitted
• composition for space and time (serial, parallel)

• compare QMF, MHEG, OMFI

• track - primary access is temporal, presentation is of sequence of movie segments, accesses only media units, leaves interaction to scripts and apps.
• object - primary access is hierarchical descent of tree, presentation is by links and then inside trees, allows everything to be manipulated as an object, allows attachment of interaction to objects (including scripts and apps.)

• deadlines for object retrieval, presentation, response to user input
• delivery engine along with file and data organization to support it

• object: placement, partial retrieval, sequencing, index, interleaving, progressive access
• separate retrieval of object description and object content
• resource recommendations

• define and prove representational power of a format
• define functional requirements and see if format meets it
• demonstrate using benchmarks

• edited video
• hypertext
• slide show presentation
• script-based interactive presentation

• storage
• retrieval
• random access
• update
• conversion

• formats
• contributions, differences, evaluation