Text - Ch 11
Multimedia File Systems and Information Models
11.1 The Case for Multmedia Information Systems
- video-on-demand and multimedia-on-demand
- File systems and DBMS are not designed for multimedia search, large amounts of data and stringent time demands on recording and delivery
11.2 File System Support for Continuous Media- Layout of continuous media files
- Buffer requirements (size, allocation)
- Admissibility of a new request if have sufficient resources
- Scheduling of requests
11.2.1 The Single Stream Case- read, store in (minimal size) buffer, consume from buffer (without ever starving)
- consider blocking, disk delays
- use different sweep and sorting to order disk accesses
11.2.2 Performance Guarantees for Continuous Media Access (SKIM)- consider file layout, scheduling of access, admissibility
- deterministic (underutilized channel) or statistical (can fail)
11.2.3 Continuous Media File System (SKIM)- CMFS was proposed by Anderson for deterministic and non services, has no special layout policy
- scheduling policies: static, greedy, cyclic; workahead and slacktime
11.2.4 UCSD Multimedia-on-Demand Server (SKIM)- continguous storage requirement can be relaxed - staggered toggling, merging strands
- admissibility criteria and scheduling algorithms (round-robin, quality proportional - better)
11.2.5 Lancaster University- CMSS, Continuous Media Storage System, continuous media stream consumed at a fixed data rate
- stripe data blocks in a sequence to disk array
- soft or hard guarantee approaches
11.2.6 Grouped Sweeping Scheduling- g groups for the n sessions
- assign similar buffer space for all groups
11.3 Data Models for Multimedia and Hypermedia Information- temporal sync, dynamic interactive behavior,hyperlinking
- structure, logical, physical, supporting retrieval
- object approaches
11.3.1 Temporal Relationships- Petri net
- presentation process
11.3.2 Hypermedia Document Models
11.3.2a MMV- MultiMedia Viewer extends DEC's CDA with sync and multimedia objects
- cue supports sync between media and interactivity: FSA with transitions triggered by Boolean expressions becoming true
11.3.2b The Amsterdam Hypermedia Model- AHM combines Dexter and CWIF (CWI multimedia model) - 2 changes:
- component objects are associated with CWIF channels, independently controlled viewing areas
- composites can specify sync relationships between components
11.3.2c HyTime- SGML with architectural forms added for time-based performances and hypermedia
- modules: base, measurement, location address, hyperlinks, scheduling, rendition
- HyOctane engine for retrieval with link management, location addressing, scheduling
11.4 Content-Based Retrieval of Unstructured Data- extract or produce text and then do text searching: Aegina
- QBE (query by example so can match features of your "sketch"
11.5 Summary- tradeoffs of disk layout, scheduling, buffering, admissibility; types of guarantees
- document architectures, authoring, content-based retrieval
Hierarchy