Rotoscope Frame Rate Mismatch

[benn90397019]

Hello all!!

I am really hoping someone will be able to help me with this. I have some videos that I need to rotoscope, shot on a phone, but when I go to rotoscope and I jump forward to the next frame, the frame appears the be the same. I will have to hit the forward frame (page down) button twice in order for it to jump forward, then three times, then two times, then three times. What settings do I need to adjust? Is it something with the frame rate?

If you know anything about this, please help me out by leaving a comment. Thank you all so much! 🙂

[Mylenium]

Without any exact info about your source fiel we can't tell you much. Clips recorded on phones use all sorts of dirty tricks like variable frame and data rates, none of which goes down well with AE, just like on a more generic level the heavy compression those files usually have doesn't make them ideal for any post work. If on top of that you're mixing up the footage interpretation, comp frame rate and whatnot, things won't get better. Start by actualyl checking these things. Generally, though, you may be unable to avoid converting the clip in another program before actually using it in AE. You may also need to set up your phone camera with some more professional recording settings to begin with to avoid all that extra work on future clips. For anything beyond that generic advice, exact info would be required.

Mylenium

[benn90397019]

Got it! And what program do you recommend converting clips over into? How would I do that?

[Szalam]

If using Adobe Media Encoder isn't cutting it, I usually use DuME (from the same folks that make DUIK - and, if you haven't tried Duik Bassel, I highly recommend it!)

I usually use QuickTime with ProRes as my intermediate codec choice

[Rick Gerard]

Open your footage in the footage panel by double-clicking it in the Project Panel, use Ctrl/Cmnd + right arrow to step through one frame at a time and make sure you don't have any duplicate frames. If you do, check the file interpretation. When you get the footage to look correct in the Footage Panel set in and out points for the footage and then create a new comp from the properly interpreted footage. Do your rotoscoping using the new comp.

[benn90397019]

Thank you for this! Followup question, when you interpret footage and change the frame rate, how do I make it so the footage does not slow down? If I change to 120 FPS, I am able to go back and forth frame by frame, but now it is much faster than the original 60 FPS clip? Thanks!!

[Rick Gerard]

If you change the frame rate then you change the playback speed. 

If your comp is 30 and you shot at 60 then just pre-compose the footage and do the Rotobrush on the nested comp. You won't lose any accuracy.

I don't have time to explain things in detail but maybe this will help. The After Effects timeline and all of the animation is based on Time, not frames. If you create a 10-second comp that is 10 fps and you change the frame rate to 60 fps, the comp is still 10 seconds long.

If you change the frame rate that you use to playback the footage then you change the time. A 60 fps shot that is 10 seconds that is interpreted at 120 fps will become 5 seconds. 

If you don't want interpreted frames in your comp then match the frame rate of the comp to the footage. If you want a lower frame rate, just change the frame rate in the comp. 

I hope that helps.