Re: 720 60p or 720 24p -- WHY FCP can remove frames

[Frank Nolan] "In Post how would FCP know which 24 frames of the 60 to pull as you have 60 distinct frames?"

Just to be clear here -this 720p24 over 60 workflow predates the HVX200 and has been in use since the varicam arrived on the market 5 years ago.

FCP knows what to do for 2 reasons.

1) the cadence of redundant frames in Panasonic's 720p HD is the industry standard 3:2 pulldown, where as the first frame ( which is actually the zero frame) is duplicated twice while the next frame is duped 3 times, with this cadence repeating over and over again. Becuase it is always the same it is simply math to remove the redundant frames that are always in the same order.
It works because all of the frame are progressive and there are NOT interlaced fields to make any "combined from interlaced fields" the normally mushy looking frames in SD.

2) There is something called an RP188 Time code track where the "flags" or markers to what frame rate the camera is recording FCP can also see these which confirms the time base. When working with Varicam footage from a deck over HDSDI FCP can read these "User Bits" indirectly from within the Kona Control Panel ( I do not believe that decklink does not allows for this)
This is where all of the variable frame rate data is held - the flags here allow for My Kona board or the software FRC in Final Cut to see what frame rate the camera was working in and remove the redundant or repetitive frames.




gary adcock
Studio37
HD & Film Consultation
Post and Production Workflows
Chicago, IL