[This is preliminary documentation and subject to change.]
Once the stream has been created and tested with the video, your tools should provide a way for the producers at the head-end to transmit the stream, with its accompanying video, to the broadcast clients.
The enhancement stream can be transmitted several ways, either packaged with the video, as in the case of VBI-line encoding, or transmitted before the show is broadcast using a means such as Internet channel broadcasting. In either case, you can use the enhancement sender object to transmit the enhancement stream. Because the enhancement sender always transmits the stream to a Microsoft Multicast Router it is independent of the actual transmission means. The implementation details of the broadcast medium are handled by hardware-specific virtual interfaces set in the router. For more information, see Working with the Microsoft Multicast Router.
If you are going to use the enhancement sender object to transmit the stream, you must first convert it to low-level format. For more information on how to do this, see Converting Events to Low-level Syntax.
If your authoring tool transmits the enhancement stream, it should provide a way to set the network interface card, IP addresses and IP ports used to broadcast triggers, file downloads, and announcements. Your application can either collect this information from the user or detect these values automatically.
For more information about using the enhancement sender object to broadcast the enhancement stream, see Broadcasting an Enhancement.
Note If you are using a custom application to transmit the stream to clients instead of the enhancement sender object, ipsend, you must implement the redundancy value described in Trigger Checksum Value.