Getting Information About Video Digitizer Components8

This section discusses functions that allow applications to obtain information about the capabilities and current state of video digitizer components.

You can use the VDGetDigitizerInfo function in your application to retrieve information about the capabilities of a video digitizer component. You can use the VDGetCurrentFlags function to obtain current status information from a video digitizer component.

VDGetDigitizerInfo

The VDGetDigitizerInfo function returns capability and status information about a specified video digitizer component.

All video digitizer components must support this function.



 
pascal VideoDigitizerError VDGetDigitizerInfo

                                          (VideoDigitizerComponent ci,

                                         DigitizerInfo *info);

ci: Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.
info: Contains a pointer to a digitizer information structure. The VDGetDigitizerInfo function returns information describing the capabilities of the specified video digitizer into this structure. See "The Digitizer Information Structure" for a complete description.

DESCRIPTION

The VDGetDigitizerInfo function returns the capability and status information in a digitizer information structure (defined by the DigitizerInfo data type).

RESULT CODE

noErr

No error

VDGetCurrentFlags

The VDGetCurrentFlags function returns status information about a specified video digitizer component.

All video digitizer components must support this function.



 
pascal VideoDigitizerError VDGetCurrentFlags 

                                         (VideoDigitizerComponent ci,

                                          long *inputCurrentFlag, 

                                          long *outputCurrentFlag);

ci: Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.
inputCurrentFlag: Contains a pointer to a long integer that is to receive the current input state flags for the video digitizer component. The VDGetCurrentFlags function returns the current input state flags into this location. See "Current Flags" for a complete description of these flags.
outputCurrentFlag: Contains a pointer to a long integer that is to receive the current output state flags for the video digitizer component. The VDGetCurrentFlags function returns the current output state flags into this location. See "Current Flags" for a complete description of these flags.

DESCRIPTION

The VDGetCurrentFlags function returns the status information into two fields that contain flags specifying the current input and output status of the digitizer component.

You can also use the VDGetDigitizerInfo function (described in the previous section) in your application to retrieve capability and current status information about a video digitizer component.

The VDGetCurrentFlags function is often more convenient than the VDGetDigitizerInfo function. For example, this function provides a simple mechanism for determining whether a video digitizer is receiving a valid input signal. An application can retrieve the current input state flags and test the high-order bit by examining the sign of the returned value. If the value is negative (that is, the high-order bit, digiInSignalLock , is set to 1), the digitizer component is receiving a valid input signal.

RESULT CODE

noErr

No error

Getting Information About Video Digitizer Components

VDGetDigitizerInfo

DESCRIPTION

RESULT CODE

SEE ALSO

VDGetCurrentFlags

DESCRIPTION

RESULT CODE