Rotate portions of a video smoothly to different degrees

[froggo]

Hello

I have a video that was recorded on a digital camera while it was being passed around. The video is tilted to different degrees depending on how each person was holding it.

I found some postings on this site about how to do hard rotations to specific chunks of a video. However, what I'm looking for is to be able to to have smooth rotation transitions between pieces (i.e. when the camera is being rotated from, say, 45 degrees to 30 degrees, i want the image to look upright the whole time, based on calibrating how much the original image is rotated at different points). Here are the specifics about what I have:

Video format: .avi
OS: Windows XP
Software available: I have access to Adobe Premiere Pro CS4.

If you have other software solutions, feel free to post. I'd prefer Premiere, but since I'm at a university, I can get access to a lot of other full version programs.
Freeware is also a happy option, but I'd prefer the convenience of a single paid program to use of multiple free programs.

Gimme a shout if you need more info.

Thanks

[guns1inger]

Depending on just how the original is moving, your best bet is probably a stabilisation program. DeShake for Virtualdub is free, and there are commercial options as well - usually as plugins for After Effects and the like.

These programs work by analysing the motion in the clips, the applying the reverse motion to them. However this will product strange effects at the edges of the screen, such as empty areas where there is no footage. This is usually compensated for by zooming into the image until these are gone, but this will give you a softer image.

[manono]

Know any AviSynth? How about V.C. Mohan's EffectRotation, part of his EffectsMany filters:

EffectRotation rotates the image part with given radius through given angle (-ve clock wise direction) Can be used to rotate scanned images or as an effect.

http://avisynth.org/vcmohan/EffectsMany/EffectRotation.html
http://avisynth.org/vcmohan/EffectsMany/EffectsMany_index.html

I've used it before with good results when a DVD's video was off axis. As guns1inger said, though, you get empty areas. I cropped them away and resized.

[froggo]

Depending on just how the original is moving, your best bet is probably a stabilisation program.

I dont think that will apply, based on my specific scenario (though correct me if I'm wrong). In a sense, think of the video as rotating to 30 degrees at minute 1, then to 45 degrees at minute 2, then 90 at min 3, 180 degrees at another point, then back to 0 degrees eventually. And each rotation usually being a full 2 second or so duration. [note: not actual rotations, as the video makes an almost 360 before returning to upright].

Im presuming that what you're describing is more for minor rotations due to some sort of shaking or unsteadiness

Know any AviSynth? How about V.C. Mohan's EffectRotation

Heard of AviSynth, but thought it only did hard rotations.
And as such, I also haven't used the EffectRotation before.

I just looked at the parameters, and you're able to input initial and final angle of rotation. Since you're also inputting start and end frames, does this imply the program figures out the incremental rotation per frame to create a smooth, 'constant speed' rotation? If so, that's prolly what I'm looking for (sans a nice, pretty gui).

I'll try getting accustomed to the program over the next few days, but if this is (or isn't) what EffectRotation is supposed to do, lemme know.

empty areas where there is no footage

Completely trivial to me. I'll prolly crop/resize the final video when sending to colleagues, but that's a simple task.

Thanks!

[manono]

Heard of AviSynth, but thought it only did hard rotations.

AviSynth has filters like TurnLeft, TurnRight and such, and I've only used this one for simple 1 to 3 degree turns for videos only slightly off kilter. However, it looks from the doc that you can have it make a slow and steady rotation, as well as a fixed rotation of whatever degree amount you like. From your original description it seemed you wanted fixed rotations of different amounts during different periods of the video. If true, combining EffectRotation with Trim to isolate the degree amount for each specific range of frames is the way to go.

http://www.avisynth.org.ru/docs/english/

[Alex_ander]

http://www.avisynth.org.ru/rotate/rotate.html

You can apply this AviSynth filter the wanted number of times, using start/end frames (along with angle number) in its parameters for each episode.

[manono]

Rereading the EffectRotation doc again, it doesn't look like you need to Trim off the different frames for the different degree rotations, because it also can be run multiple times to rotate different portions of the video differently.

Good find, Alex_ander. It seems Fizick's filter does the same as V.C. Mohan's, but faster I guess.

[Gavino]

I just looked at the parameters, and you're able to input initial and final angle of rotation. Since you're also inputting start and end frames, does this imply the program figures out the incremental rotation per frame to create a smooth, 'constant speed' rotation? If so, that's prolly what I'm looking for (sans a nice, pretty gui).

Yes, both EffectsRotation and Fizick's Rotate will do this.
If a constant speed (linear variation) is not good enough, there is also the Zoom plugin from WarpEnterprises:
http://avisynth.org/warpenterprises/files/zoom_25_dll_20050122.zip
This allows for spline curve variation, but it's slower than the others.