Wrong resolution when importing footage from AE to Mocha

Ok, so I’ve been trying to understand exactly why this is happening and how I can fix it for the past 2-3 hours, but I can’t seem to figure it out. So I hope someone here can help me…


So the deal is, I’ve done both a camera track aswell as a mask for a tree in the foreground of my shot using mocha, which turned out superb and took me a long time to do. So I’d like to avoid having to re-do it. The way I imported the footage into mocha was through the “Animation - Track in Mocha AE” shortcut in After Effects. And the after effects composition is a direct link composition from a Adobe Premiere sequence that’s in 1920x800. But the source footage is actually 1920x1080. So the result is that I’m working in 1920x800 in After Effects and Premiere, but when I import the footage into mocha it’s telling me the footage is in 1920x1080. Hence, my foreground tree mask shape from mocha pastes fine into AE on the first frame, but over time goes completely out of sync, as demonstrated on the two pics below (which are about 150 frames into the track).


[caption id="" align=“alignnone” width=“960”] Mocha tree mask[/caption]

[caption id="" align=“alignnone” width=“960”] AE tree mask[/caption]

Any ideas on how to fix this? I haven’t really found anything except maybe exporting a jpeg sequence of the shot to get the resolution correctly into mocha, and re-doing the whole track in that new mocha project. It just seems pretty unnessesarily complicated. And like I said, I’d like to avoid re-doing the track if at all possible, since the one I already did turned out so great.


EDIT: I completely forgot to mention, the original file format is a h.264 MPEG Movie file straight from my Canon 600D shot at 1920x1080 at 23.976fps. If that’s of any interest.

Is the crop in AE an actual 1920x800 source, or is it 1920x1080 cropped into a 1920x800 comp? If the latter then it shouldn’t matter what the size of the crop is, as it’s not restricting the original source.

If the playback is out of sync, What you might want to check is if the frame rate of the mocha project matches the AE comp. If it is different, change the mocha frame rate to the correct value and try exporting again.

Well, it’s a 1920x1080 source pre-composed to a 1920x800 composition, so I am marking that 1920x800 composition when I sent it to mocha. Quadruple-checked the framerate at this point, it’s set to 23.976fps in every possible place and has been since the start of the project, so that isn’t the issue.


The mask isn’t exactly “out of sync” so much as it’s just off the target. You can see on the pictures how it’s off to the left in AE, later in the shot when the camera pans towards the right, it’s kinda like if the mask pasted in AE exadurates those movements. So whenever the camera pans left, the mask goes off towards the left. Whenever the camera pans right, the mask goes off towards the right. And whenever it goes back to the same spot as frame 1, it looks fine.


EDIT: Taking a closer look at the shot in Mocha compared to AE, it doesn’t seem like it’s being stretched or cropped. Looks like I am getting the full original 1920x1080 source in mocha which is just getting cropped by the 1920x800 format in the AE comp.

Oh, I figured out the problem. I feel stupid as hell for not realizing this sooner!


The problem is… that mocha is simply exporting the WHOLE length of the source footage, which is over 800 frames, but I’ve only tracked frame 69 to 636, which is what I’m working with in the AE comp. Just gotta figure out how to export only the frame-range I’m after in mocha now… (it’s been a while since I’ve used mocha, maybe you can tell :p)

Right, in mocha AE it will always use the whole frame range, so the best thing to do is to paste the mask to a new solid and slide the layer back in time by 69 frames. You can then use the solid as the track matte for the layer below.

It’s a bit weird though, I already pasted the corner pin track data from both of my two mocha layers into two null objects in AE, and I had no problem with those. This problem specifically happened with the shape data. But I just tried that time-shift sollution and it’s definitely alot better now. Thanks for your help!

That’s right, and it IS a bit confusing. Tracking data is always pasted from the playhead, so it will be in sync from your timeline.
Shape data has to be pasted from frame zero to make sure multiple layers of roto sync correctly. We’re actually working on changing this so shape data is easier to use!

Awesome, that’s good to know! Looking forward to future updates then :smiley: