Sources Panel

The sources panel serves as a starting point for the webcast. It contains mechanisms to start and display sources transmitting into the studio session. A column of small, slowly refreshing thumbnail images represent sources as shown in figure 6. Below these thumbnails are buttons that represent control services. Services perform computations or actions on behalf of an application. These services can be media or control services. A media service produces a packet stream (e.g., audio or video). A control service provides an interface to control an entity (e.g., room lights, a floor control application, etc.). The Service pull-down menu at the bottom of the sources panel allows the director to add a media or control service interface to the sources panel. The video sources displayed in the sources panel are called the Media Service Set. The control interfaces are called the Control Service Set. The Control Service Set shown in figure 6 includes three services (i.e.- Room405, SpecialFx, and Replay) that display dialog boxes to control entities or instantiates a media service. The Room405 button displays various room controls (e.g., light controls, projection screens). The SpecialFx button displays a dialog that instantiates a video-effect services and adds it to the Media Service Set. The Replay button, shown in figure 7, allows the director to add a stored material playback stream to the Media Service Set.

  

Figure: An example control service dialog. This dialog allows the director to start an archive replay source. The two entry boxes specify the archive material and audio session.

Services are presented to the director through the Service pull-down menu, which displays a hierarchical menu based on the service location. The hierarchy has the following structures:

organization/building/room/service

and

Locationless/service

Figure 8 shows the hierarchical structure for two services.

  

Figure: Examples of service menu hierarchical structure. The hierarchy on the left shows a location dependent service and the hierarchy on the right shows a location independent service.

Selecting a menu item initiates the service. A media service transmits a stream to the studio session when initiated. If it is a video stream, a thumbnail computed from the stream is added to the sources panel. A control service adds a button to the Control Service Set displayed below the column of thumbnails.

The Service pull-down menu changes to reflect the current environment. If, for example, a remote camera is installed during a webcast, the service process associated with the camera will announce its existence. The dc will detect this new service through the service discovery protocol and add it to the Service pull-down menu.