Media control and processing

The following section explains how the Application system and the Real Time system work together to provide K2 system functionality.

The high processing requirements of digital video can overwhelm the processor on a standard desktop PC, resulting in wait-times that destroy the video’s essential real-time aspect. The K2 system avoids this problem by providing dedicated systems that isolate processing needs. The components that work together to provide this functionality are as follows:

Application system — Dedicated to control, configuration, and networking functions that do not require real-time accuracy. The Application system has the following components:

  • Application software provides the user interface for operating the K2 system. 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.

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.

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.

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