[This is preliminary documentation and subject to change.]
A tuning space enables a broadcast client to resolve overlapping channel numbers used by multiple broadcast sources. For example, suppose a computer has both an analog television tuner and a satellite tuner card installed. If the two broadcast systems each have a channel 1, a conflict occurs. To prevent such conflicts, Broadcast Architecture defines each input source as a separate tuning space, assigning it a unique identifier.
Each tuning space has both a unique numerical identifier, and a human-readable name such as analog tuner, cable, or satellite.
You can use methods of the TSS object library to map a tuning space identifier to its user-readable name and vice versa. For example, if your application needs to present a list of tuning spaces to users, it can look up the tuning spaces in the Guide database and then map each tuning space to a human-readable name. Conversely, when a user selects a tuning space, your application needs to map the tuning space name to its identifier before your application can tune to a channel in that space.
To map an identifier to the tuning space name, your application calls the ITelevisionServices::TuningSpaceNameFromNumber method. To map a name to its corresponding identifier, your application calls the ITelevisionServices::TuningSpaceNumberFromName method.
For more information on resolving channel overlap, see Overlapping Channels.