[This is preliminary documentation and subject to change.]
Because the broadcast medium used to transmit enhancements, such as a Vertical Blanking Interval (VBI) or Local Area Network (LAN), has a finite bandwidth, there is a limit to the number and size of events that can be transmitted during an interactive show.
Your authoring tool should provide a way for users to enter the available bandwidth, and an indication of how much of the bandwidth is utilized by the current stream. Your tool should warn the user when the enhancement stream exceeds the given bandwidth and enable the user to reduce the number or size of events.
The stream compiler objects provide several tools to assist your authoring tool in managing bandwidth utilization. The EnhEvents.Bandwidth property stores the total available bandwidth for the broadcast medium. The EnhEvent.Length property contains the length of the file being transmitted, in bytes. Other methods and properties enable your application to determine the time and bandwidth required to transmit an event. EnhEvent.XmitDuration determines the time required to transmit an event based on its length, the bandwidth, and the file transmission redundancy. By comparing the show time to the time required to transmit all of the stream events, you can calculate the percentage of the available bandwidth currently used.