Overkeel

Overkeel is an iMovie plug-in that rotates picture 180°. One might want to apply it to footage shot with the camera upside down, for example, when using a cheap camera stabilizer for low angle shots without the inverting bracket.

Download

WARNING: No warranty. Use at your own risk.

• overkeel-1.0.zip - precompiled binary;
• overkeel-1.0.src.zip - source code.

Overkeel source code is distributed under the MIT license.

Installation

Drag Overkeel.bundle to ~/Library/iMovie/Plug-ins/.

Usage

1. Start iMovie;
2. Select clip(s) to rotate;
3. Click "Effects";
4. Select "Overkeel (rotate 180 degrees)";
5. Click "Apply".

Technicalities

Individual frames in a DV stream are compressed using JPEG algorithm. JPEG images can be rotated without quality loss by flipping signs of DCT coefficients. Unfortunately a DV clip cannot be rotated this way because the pixels are rearranged by DV encoder before JPEG compression.

Overkeel discards the last scanline so that after rotation top and bottom frames don't switch (odd scanlines remain odd and even scanlines remain even).

Similar Plug-ins

• turn clip by cf/x and Christian Franz;
• Upsidedown by Stupendous Software.

Version History

01-Jun-2005 1.0 - Initial release.  Tested with iMovie HD 5.0.2 (111)
                  on Mac OS X 10.3.9.