KSPROPERTY_TUNER_STATUS_S structure (ksmedia.h)
The KSPROPERTY_TUNER_STATUS_S structure describes the progress of a tuning operation for TV and radio tuner devices, including present tuning frequency.
Syntax
typedef struct {
KSPROPERTY Property;
ULONG CurrentFrequency;
ULONG PLLOffset;
ULONG SignalStrength;
ULONG Busy;
} KSPROPERTY_TUNER_STATUS_S, *PKSPROPERTY_TUNER_STATUS_S;
Members
Property
Specifies an initialized KSPROPERTY structure that describes the property set, property ID, and request type.
CurrentFrequency
Specifies the current tuner frequency. This value is in hertz (Hz).
PLLOffset
Specifies the phase locked loop (PLL) offset in multiples of the tuning granularity. This is used if the tuner strategy is KS_TUNER_STRATEGY_PLL. If the tuner strategy is not KS_TUNER_STRATEGY_PLL, this value has no meaning. The following table demonstrates the value to be returned by the minidriver for various tuning conditions, assuming the tuning granularity is 62.5kHz:
| Frequency Offset | PLLOffset |
|---|---|
| +125,000 | +2 |
| +62,500 | +1 |
| Perfectly tuned | 0 |
| -62,500 | -1 |
| -125,000 | -2 |
SignalStrength
Specifies the amplitude of the signal. This is used if the tuner strategy is KS_TUNER_STRATEGY_SIGNAL_STRENGTH. Regardless of the tuning strategy supported by the minidriver, the valid values for this member are:
| Value | Meaning |
|---|---|
| -1 | Strength not Available. |
| 0 | Not on an acceptable frequency. |
| 1 | On an acceptable frequency. |
Busy
Indicates if the minidriver is presently busy with the process of tuning. This member must be set to TRUE if the minidriver is currently tuning to a channel. Otherwise, if the minidriver is not currently tuning to a new channel, this member must be set to FALSE.
Remarks
For more information about the PLLOffset and SignalStrength members see PCI based TV capture. If your tuner device supports radio tuning, see Video Capture Devices with Radio Tuners.
Requirements
| Requirement | Value |
|---|---|
| Header | ksmedia.h (include Ksmedia.h) |