IDigitalCableTuneRequest Interface
| Microsoft DirectShow 9.0 |
IDigitalCableTuneRequest Interface
The IDigitalCableTuneRequest interface provides methods for tuning to a channel in a digital cable network. The DigitalCableTuneRequest object implements this interface.
OCUR Devices: This interface supports OpenCable Unidirectional Cable Receiver (OCUR) devices. See OCUR Devices.
In addition to the methods inherited from IATSCChannelTuneRequest, the IDigitalCableTuneRequest interface exposes the following methods.
| Method | Description |
| get_MajorChannel | Retrieves the major channel number. |
| get_SourceID | Retrieves the source identifier, which maps to a physical channel. |
| put_MajorChannel | Sets the major channel number. |
| put_SourceID | Sets the source identifier. |
Remarks
This interface provides three ways to specify the program for the tune request:
- Virtual channel number (VCN). To set the VCN, call IChannelTuneRequest::put_Channel. (This interface inherits IChannelTuneRequest through the IATSCChannelTuneRequest interface.)
- Major channel and minor channel. These are used when an ATSC broadcast is transmitted over cable without remultiplexing the streams. To set the major and minor channels, call IDigitalCableTuneRequest::put_MajorChannel and IATSCChannelTuneRequest::put_MinorChannel, respectively.
- Source identifier. The source identifier is mapped to a physical channel in the virtual channel table. To set the source identifier, call IDigitalCableTuneRequest::put_SourceID.
Only one of these settings should be used in any one tune request. Set the other values equal to BDA_UNDEFINED_CHANNEL (-1). Also, if the physical channel is set in the locator, the physical channel overrides any of these values.
Note that the base channel number from IChannelTuneRequest has a different meaning when it is used in this interface than it does in the IATSCChannelTuneRequest interface. In this interface, the base channel number is the VCN, not the major channel.
See Also