All 720-line HD formats are progressive; there is no such thing as 720i. You can safely assume that the footage is progressive.
You cannot safely assume that the true frame rate is 59.94 fps, though. It could also be 29.97 fps (doubled) or 23.976 fps (with something like 3:2 pulldown, just across entire frames instead of fields). If you step through the footage frame by frame, it should be pretty clear.
If the footage is truly 59.94 fps, you might preserve some of the motion by compressing to 29.97 interlaced fps. If it’s 23.976, you can reverse-telecine and compress at 23.976 fps.
Walter Soyka
Principal & Designer at Keen Live
Motion Graphics, Widescreen Events, Presentation Design, and Consulting
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