| Platform SDK: Broadcast Architecture |
The Tuning Spaces registry subkey lists all tuning spaces, that is all sources that provide Program Guide data. Each tuning space has a tuning identifier that uniquely identifies it.
The list of identifiers specifying the available tuning spaces is found under the Tuning Spaces subkey as follows:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\TV Services\
Tuning Spaces\TuningIdentifierList
TuningIdentifierList is an ordered list of all tuning identifier subkeys. This list provides a way to choose the appropriate loader for a tuning space. The following table lists and describes the values under each TuningIdentifierList subkey.
| Value name | Data type | Meaning |
|---|---|---|
| Name | String | Short name of this tuning space for display to the user. |
| AMFClass | GUID | Globally unique identifier (GUID) passed to Loadstub.exe to run this loader. |
| Description | String | Description of this tuning space for display to the user. |
| Loader | GUID | GUID for the Guide database loader used for this tuning space. |
| MinChannel | short | Minimum channel number acceptable for this tuning space. |
| MaxChannel | short | Maximum channel number acceptable for this tuning space. |
| Devices | String | List of logical device names for all devices that support the Microsoft® ActiveX® control for video (the Video control). |
A broadcast receiver card can handle more than one tuning space. For example, NTSC cards provide both cable and over-the-air broadcast channels from an external antenna. In these situations, the installation portion of Television System Services (TSS) must add values to the registry for each possible tuning space. Cable and broadcast need to be treated as two separate tuning spaces, because their channel numbering spaces overlap and conflict in many cases.