Inside Macintosh: QuickTime Components /

Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Video Digitizer Component Functions / Controlling Analog Video

VDSetInputGammaRecord

The VDSetInputGammaRecord function allows an application to change the active input gamma data structure. Gamma structures give applications complete control over color filtering transforms.

pascal VideoDigitizerError VDSetInputGammaRecord
                            (VideoDigitizerComponent ci,
                              VDGamRecPtr inputGammaPtr);

ci

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

inputGammaPtr

Contains a pointer to an input gamma structure. The input gamma structure is defined by the gammaTbl data type. For more information about gamma structures, see Designing Cards and Drivers for the Macintosh Family, third edition. The video digitizer component uses the input gamma structure specified by this parameter.

SPECIAL CONIDERATIONS

Note that the VDSetInputGammaRecord function may override the current gamma value and contrast settings if the video digitizer component uses a lookup table to implement brightness and contrast.

RESULT CODES

noErr	0	No error
digiUnimpErr	-2201	Function not supported

SEE ALSO

Your application can get a pointer to the current input gamma structure by calling the VDGetInputGammaRecord function, which is described in the next section.

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