How to use ofQTKitGrabber to also record data - numbers and text

quicktime allows the creation of movies that contain more than one track. most of the time that is sound.
but how would i record any type of data (numbers, text) along with every new frame.

this would allow me to later on play the movie and also retrieve the recorded data.

https://developer.apple.com/library/content/documentation/QuickTime/RM/MovieBasics/MTEditing/F-Chapter/6CreatingTracksandMe.html

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