Inside Macintosh: QuickTime Components /

Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Video Digitizer Component Functions / Controlling Analog Video

VDGetBlackLevelValue

The VDGetBlackLevelValue function returns the current black level value. Black level values range from 0 to 65,535, where 0 represents the maximum black value and 65,535 represents the minimum black value.

pascal VideoDigitizerError VDGetBlackLevelValue
                            (VideoDigitizerComponent ci,
                              unsigned short *blackLevel);

ci

Specifies the video digitizer component for the request. Applications obtain this reference from the Component Manager's OpenComponent function.

blackLevel

Contains a pointer to an integer that is to receive the current black level value. The video digitizer component places the black level value into the field referred to by this parameter.

DESCRIPTION

Applications can set the black level value by calling the VDSetBlackLevelValue function (described in the previous section). Applications can obtain the recommended black level value by calling the VDGetVideoDefaults function (described on page 8-66).

RESULT CODES

noErr	0	No error
digiUnimpErr	-2201	Function not supported

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