Grass Valley K2 Media Client System Guide v.3.3 - Manual (Page 34)

34 K2 Media Client System Guide June 9, 2009
Chapter 1 Product Description
The software runs as Windows programs.
• The Media File system manages clips. It includes a database that associates the clip
with its video, audio, and timecode files and a dedicated file system (separate from
the Windows file system) that controls access to the raw data that makes up each
file. Any reading and writing of clips, be it through play and record operations or
through file transfers and media streaming, is managed by the database. The
database and file system run as Windows programs.
The Storage system includes the media disk drives, controllers, drivers, and adapters
necessary for access and movement of the data. While the primary data flow is within
the overall control of the Real Time system, some components and their
communication pathways cross over into the Application system. For example, the
RAID controller board plugs into the motherboard and accesses media drives in
internal storage models, yet it is controlled by Windows. The media drives appear as
the V: drive to the Windows operating system.
The Real Time system manages the media flow between the Storage system and the
inputs and outputs. The Real Time system has a dedicated processor and
time-sensitive mechanisms to serve media processing needs while maintaining
real-time accuracy.
When you control play and record operations from within the Application system you
trigger a chain of events that eventually crosses over into the Real Time system and
results in media access. The following sequence is an example of this type of chain of
events:
1. A user operates the Player application to play a particular clip. The Player
application asks the Media File system for permission to access the clip. The Media
File system grants access. In shared storage models, the Media File system
enforces shared storage policies in order to grant the access. When access is
granted, the Player application initiates play access to the clip.
2. The database identifies the files that make up the clip and the file system instructs
the Storage system to open access to the files.
3. The Storage system finds the raw data and opens the appropriate read access. At
this point both the Application system and the Real Time system are involved.
Windows controls the media drives and controllers, so the Real Time system
makes file requests to Windows and it causes the data to be transferred to buffers
on the Real Time processor. The data is then available to the Real Time system so
that it can be processed at exactly the right time.
4. The Real Time system processes the media, decompresses it, adjusts its timing, and
moves it as required to play the clip as specified by the user.
Loop through and E to E
Each of the K2 Media Client models has different mechanisms and behaviors related
to input signals routed to output connectors, as described in the following sections.
Also refer to Appendix A, Remote control protocols for information regarding E to E
commands.