Inside Macintosh: QuickTime Components
This chapter discusses video digitizer components. Video digitizer components provide an interface for obtaining digitized video from an analog video source. In QuickTime, the typical client of a video digitizer component is a sequence grabber component (sequence grabber components are described in the chapter "Sequence Grabber Components" in this book). Sequence grabber components use the services of video digitizer components and image compressor components to create a simple interface for making and previewing movies. However, video digitizer components can also operate independently, placing video into a window.
Most applications never need to communicate directly with a video digitizer component. It is strongly advised that your application use the sequence grabber component instead; it isolates you from the myriad of details associated with video digitization.