Inside Macintosh: QuickTime Components /

Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Video Digitizer Component Functions / Controlling Analog Video

VDSetBlackLevelValue

The VDSetBlackLevelValue function sets 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 VDSetBlackLevelValue
                            (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 contains the new black level value. The video digitizer component attempts to set the black level value to the value specified by this parameter. The digitizer component returns the new value, so that the application can avoid using unsupported values in future requests.

RESULT CODES

noErr	0	No error
digiUnimpErr	-2201	Function not supported
qtParamErr	-2202	Invalid parameter value

SEE ALSO

Applications can get the current black level value by calling the VDGetBlackLevelValue function (described in the next section). Applications can obtain the recommended black level value by calling the VDGetVideoDefaults function (described in the previous section).

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