Section
Four: Digital Video Client/Servers
Asset
Management
Asset management
includes both digital video files and users. User file management
is provided for authentication, usage monitoring and accounting, particularly
for "pay-per-view" applications. Basic file management, particularly
for assets distributed across servers, involves loading, replicating,
distributing and deleting files. File management should be available
remotely via a standard Web browser. Several features of asset management,
beyond basic file control, include:
- Management
of title copies in different formats and bandwidths.
- This management
should include streaming by the server to the client of the selected
asset copy based on factors such as bandwidth at the client, bandwidth
availability on the network and best available copy availability.
- Security. Security
should include support for authorization by password, IP address
or other scheme. File security should support encryption.
- Video indexing
is a developing area and can include structured metadata indexing,
keyword and natural language searching, relational table indexes,
storyboard creation and indexing and visual object recognition.
The capabilities
of each vendor are:
CyberStorage Systems'
Media Server provides an SQL database to define users and access to
content. The Media Server will not automatically identify duplicate
assets transcoded to different formats or bandwidths but does support
storing, cataloging and separating duplicates so users can only retrieve
the appropriate asset for their system. Tracking and billing functionality
is provided for "pay-per-view" applications. Tracking is accomplished
by requiring login to the CPV server before any assets can be requested
and streamed. Assets may be categorized through customizable catalog
fields.
3CX supports Windows
NT role-based security and the secure socket layer (SSL) for data
integrity over the Web. Advanced file management and indexing are
provided with the Network Video Explorer, a multimedia applications
product that includes Microsoft's Jet database engine and a relational
database for storing metadata that "follows closely" the IMS Meta-Data
standard. Network Video Finder is a web-based video context search
tool that includes a category builder for three-tier information retrieval.
The administrator can design a custom information structure and complete
the entry form to create searchable context for each video asset.
A built-in video search engine indexes the context database and retrieves
video assets from search queries.
IBM's VideoCharger
VOD server and Digital Library management system support the transcoding
of digital video titles into multiple formats and bandwidths but do
not support automatic streaming of different formats/bandwidths based
on established parameters. Instead, all instances of a title would
be grouped into a title folder, which could be discovered through
a parametric search, and the appropriate copy selected by the user
for streaming. VideoCharger includes a kerberos ticket for each video
asset as part of the metadata cataloging to set playback limits on
each video asset. Digital Library supports a variety of digital objects,
including still images, video, audio and text. Digital Library provides
a variety of indexing schemes, including Dublin Core or a user-designed
database model. Z39.50 can be employed for searching and sharing assets
across institutions. QBIC (Query by Image Content) is provided for
object component recognition (shape, color, texture, etc.) within
still images. A similar object recognition product for video is in
development. IBM's digital watermarking technology for images is also
provided Digital Library can manage other streaming servers with an
API to develop hooks into the file structure. IBM has prepared an
API for RealServer support.
Panasonic provides
management for media, categories and users. The user database provides
the system security features through its logon function. No information
was provided on cataloging and indexing capabilities.
Starlight's Management
product, StarCenter, relies on Windows NT security but is extensible
to other security mechanisms. StarCenter manages multiple encoding
instances of a title according to three factors: client capability,
administrative policies at the server and current resource availability.
Based on these factors, the best available copy is streamed to the
requester. StarCenter is interoperable with third party indexing systems
and plans to develop a tight integration with a third party indexing
product as a future development. StarCenter supports streaming servers
from Starlight (StarWorks), Microsoft and Real Networks. StarCenter
provides usage tracking, file replication, authoring assistance and
media clip management.
SGI's WebFORCE
MediaBase supports security and authentication for URLs and provides
an API (AAA) for enhancing security. MediaBase is sold with an Informix
database, which stores metadata, including user-defined keywords and
comments about each asset. The asset itself is stored in a real-time
file system, separate from the relational database providing query
and retrieval. Oracle can be substituted for Informix. Database set-up
and management is hidden for Informix but would be necessary for Oracle
implementation. Multiple formats of the same title are stored as a
composite title. MediaBase uses a feature called Client Capability
Based Streaming to query the MediaBase client, determine its bandwidth
capability and stream the appropriate format. StudioCentral, a bundled
third-party asset management environment, can create a complete media
repository, including customized data types, metadata formats and
storage mechanisms. StudioCentral is database independent; the StudioCentral
Developer's Kit provides database keys and extended type facilities
for Oracle 8 and Informix Dynamic Server.
CISCO IP/TV's
Content Manager offers password protection, encryption and file management
through a built-in database, including keyword indexing. Keyword queries
can be made through the IP/TV client to identify media assets. CISCO's
StreamWatch provides viewer and asset information for up to five simultaneous
streams. Viewer information includes identification of the viewer
(physical location, network address, email address, etc.) and time
viewer joined and left a given program. StreamWatch provides quality
information about the data stream itself, including jitter, number
of packets received and lost, and amount of bandwidth utilized. StreamWatch
can trigger bill-back accounting and can be reported into a database
for spreadsheet and report generation.
Advanced Modular
Solutions/Digital Bitcasting supports player-based or user-based authentication,
using http security protocols. The Virage VideoLogger is bundled with
the Real Networks G2 server and client for asset management. Virage
VideoLogger uses advanced image analysis to create content-based segments
based on scene changes, camera changes, etc. Distinct keyframes are
extracted to create a digital storyboard for visual content indexing.
The index thus developed can be output to a variety of formats, including
a flat file or database management system.
InfoValue's QuickVideo
Archive (QVAR) organizes media assets into databases for interactive
browsing and playback. InfoValue states that it seamlessly supports
all third-party applications, including security, indexing and retrieval
systems.
Concurrent's MediaHawk
server requires administrators of the system to log in and provide
a username and password for access to video assets but would also
support any UNIX-aware security mechanism, such as kerberos. Currently
the following index fields are supported for each asset: title, length
(minutes and seconds), number of frames, frame rate per second, and
asset file size.