Grass Valley K2 System Guide v.7.2 - Manual (Page 28)

28 K2 System Guide 07 April 2010
Chapter 1 Product Description
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
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 dedicated processors 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, E to E, and feeds
Behaviors related to input signals routed to output connectors are described in the
following sections. Also refer to
Appendix A, Remote control protocols for
information regarding E to E commands.
Recording synchronous and asynchronous feeds
For best results in all workflows, use synchronous feeds, defined as follows:
• All outputs are locked to the house reference
• All inputs are genlocked to the house reference and at zero time
The SD-00 K2 Media Client, the HD-00 K2 Media Client, the K2 Summit Production
Client and K2 Solo Media Server can record inputs that are asynchronous, with the
following considerations:
• The encoder clock and the audio clock are derived from the input signal, which
enables frame accurate recording of all inputs.