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Two types of captions are available:
- EIACEA-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.
- EIACEA-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.
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