Two types of captions are available:
CEA-608, SD only: it is read directly from Line 21 of the picture data (= first visible line. Note the white "blocks" in the picture – these are encoded closed captions). It is being extracted from the picture and written as a closed captioning track into the QuickTime movie.
CEA-708, HD only: it is read from VANC Line 9, which is not a visible line. It is directly copied as a SMPTE334M packet into the closed captioning track of the QuickTime movie.
No special setup is required. If you see the CC logo in just:control Closed Captions are being recognised and will be recorded into the QuickTime movie, SCC sidecar file (appropriate Destination Preset necessary) or into the MXF container (XDCAM HD422 only) automatically.
