Application-Defined Function(IM: QC)

Inside Macintosh: QuickTime Components /: Chapter 8 - Video Digitizer Components / Video Digitizer Components Reference

Application-Defined Function
Applications can provide a custom interrupt function in the userInterruptProc parameter of the VDSetDigitizerUserInterrupt function. Every custom interrupt function must support the following interface:
pascal void MyInterruptProc (long flags, long refcon);
flags
Indicates when the interrupt function has been called. The video digitizer component sets these flags to indicate the circumstances in which the function has been called. The following flags are defined:
Bit 0
Even-line field interrupt. If this flag is set to 1, the video digitizer component is about to display an even-line field.
Bit 1
Odd-line field interrupt. If this flag is set to 1, the video digitizer component is about to display an odd-line field.
refcon
Contains parameter data that is appropriate for the interrupt function. The application assigns the value of the reference constant when it sets the interrupt function.