29.97 frame repeats

Just curious, when you play back footage shot at 29fps. You, well, at least I do, get double frames throughout the second sporadically placed every second, it makes garbage matt key framing impossible.

Is there a way to fix this so I wouldn't have to key every frame stroke throughout motions within the shot? Playing with the progressive scanning wont help.

Would this problem happen at 24 fps?

 

What camera are you using, and do you have it set to some kind of 24p mode?

 

I am currently using the sony trv 900 and shooting at 29 frames.

dorkmanscott, when you shoot, and go back and look at your footage in AE and move down the line frame by frame, do you have any repeat frames? and if not or if so, what fps are you shooting on?

 

Incidentally, the number is 29.97, not 29.997. Maybe this is your problem? Do you understand interlace? It could be that too. If either of these are unfamiliar to you, welcome to the world of digital video.

-Spiff

 

Not unless the camera's set up to do that to conform one frame rate to another.

Is your composition in AE set to the same frame rate that you shot it (29.97 fps) or is it set to, say, an even 30 or an even 29? Or, as Spiff said, the incorrect value 29.997?

That may be your problem.

 

No, the title of the thread was a typo. Yes, all my settings are aligned to 29,97fps.

So Spiff, you dont have any frames that repeat during you playback, only visible at a frame by frame rate?

If not, it most indeed sounds like a problem that is currently only haunting me. And yes, I understand the interlacing concept, I just mentioned it cause it was one of several things I tried to do to correct the problem.

 

I only get repeat frames if I'm working with time re-sampling.

How often do you get these repeat frames? Is it on the order of once every 30-100 frames? If so, it's probably a drop-frame timecode thing. If it's on the order of every 2 or 3 frames, one would normally expect a pull-down or an improper composition frame rate.

-Spiff

 

I had this problem once when I imported off of someone else's camera with Windows Movie Maker. I didn't verify it, but I think what I did was import at 30fps rather than 29.97, so the program compensated. Every 10 frames or so I had a repeat frame. That became pretty annoying during the roto process, but I had no way to re-capture it.

-Vaportrail

 

Thanks a bunch guys, and yes, it happens every ten frames or so, so it must be how I am capturing through preimer. I think thats it. It's kinda sad, I have had this problem since I started roto work over a year ago, just finally got fed up and thought, um.. that shouldnt happen.

Thanks again, as always, ya'll have been a great help

 

Ah yes, I remember the days of thinking I was seeing double and frames repeated themselves in odd places. Such is the evil of 29.97fps.

One suggestion I have that can remedy this is to snoop around the web and find one of the good freeware utilities that specialize in de-interlacing. Film your scenes in 30i if possible. If not, this suggestion is pointless. Anywho, shoot at 30i, de-interlace the footage, then load it into your Post-Pro apps.

Several universities such as MIT and USC have free utilities tucked away in their graphics department websites and are free in most cases.

If you cannot find a free de-interlacing utility, you can try using 30i footage and then doing a Pixel Shift type operation on the footage. Only a .3-.5 pixel shift is necessary. If you get good at it, your footage will be almost as good as 30p (Progressive Scan) footage.

My advice above is not a fix to repeating frames, it is a different approach which negates the 29.97fps gremlins.

A good resource for the history and solutions to this issue is the forum over at DVInfo.net. The people on there are mostly pro filmers or camera technicians that understand these issues and can give you a prompt clean response. I use that website all the time for questions that I think are "out there" but it turns out I am not the first to ask and often a solution (that doesn't cost thousands of dollars) exists.

I never have trusted the features in most Post-Pro apps when it comes to ripping your footage to a PC. Yeah, using an extra utility adds a step, but that one step can alleviate many problems if you take the time to try it before jumping into AE or Premiere. You can also give VirtualDub a try if you want to delete the duplicate frames manually. VirtualDub offers this feature for free and it is a very small utility, leaving space for your footage.

There is a lot of good advice in the other posts in this thread. Read them over and try them out. In the end, whatever works for you and makes you happy is what counts.

v/r
Crimsus