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Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Video Digitizer Component Functions / Selectively Displaying Video

VDGetNextKeyColor

The VDGetNextKeyColor function allows your application to obtain the index value of the active key colors in cases where the digitizer component supports multiple key colors. Your application can use the VDGetKeyColor function (described on page 8-83) to retrieve the first key color in the list. Subsequently, your application can call the VDGetNextKeyColor function to retrieve the other colors in the key color list.

All video digitizer components that support multiple key colors must support this function.

pascal VideoDigitizerError VDGetNextKeyColor
                                  (VideoDigitizerComponent ci,
                                     long index);

ci

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

index

Specifies a field that is to receive the index of the next key color. This index value identifies the key color within the currently active color lookup table. If there are no more colors left in the list, the digitizer component sets the field referred to by the index parameter to -1.

DESCRIPTION

The VDGetNextKeyColor function returns an index value of -1 when there are no more colors in the list.

RESULT CODES

noErr	0	No error
digiUnimpErr	-2201	Function not supported