Detecting VBI or true video height?
Containers like LXF/GXF/MXF allow EIA-708 (VBI) streams but as far as I know they do not encode the video data -- the blanking interval -- that originally contained those streams. That would run counter to the idea that codecs embody, that of squeezing out redundant information. I could be wrong, but I've never seen or heard of a codec that encodes invisible lines.

You could scan the file for the packet headers that identify caption / VBI streams, and if you find them you could impute a frame size that would have contained them, but you could do that anyway: any encoded video, if it were output as a TV signal, would have associated blanking, whether it contained captions or not.