Oracle Video server, Manual

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What is a Digital Video Client?
Concepts 1-7
Tier 3: Data Server
The Data Server tier contains the target services which the client needs to access to
get application-specific data. In the OVS system environment, the Data Server tier
consists of the Oracle database (optional). A database is a reliable repository for
persistent storage of structured data. The OVS system can use the Oracle database
to write and query database tables associated with OVS processes, including logical
content, clips, and schedules.
Server Layer
The Server Layer provides the basic functionality for each tier.
Cartridge Layer
The Cartridge Layer provides programmatic functionality for the Server Layer of
each tier.
Communication Layer
The Communication Layer provides communication between servers, cartridges,
and tiers.
What is a Digital Video Client?
If digital video is so large that it must be stored on, and delivered from, a video
server, how do you actually obtain and view the video information in the stored
digital video? The video client machine is responsible for obtaining, decoding, and
displaying the video stored on the server.
Most commonly, the client machine requests the video from the server. In a video-
on-demand configuration, video delivery is always a result of requests from the
client; the server does not send digital video content until specifically requested to
do so. The video client then uses either software or hardware to decode the digital
video it requests from the server, and displays that video for the viewer. (In a
scheduled video system, the client does not explicitly request video delivery, since
the delivery schedule has already been established.)
The client does not store the video it displays. Storage and delivery are left to the
server machines, which are large and fast enough to handle the demands of
delivering large amounts of video data. The client requests, receives, and displays
the digital video but does not retain that data—once the digital video data has been
displayed, it no longer exists on the client machine. This means that the client
machine needs only the relatively small amount of system resources necessary to
store and operate the client software, not the digital video itself.