Once a beamer must be placed slightly skewed to illuminate the canvas, the image is distorted. Modern projectors have a build in feature called "keystoning" or "lens shifting" to transform a trapezoidal image into a rectangular image. Old/cheap projectors do not have such a build-in image post-processing, therefore:
It would be great to have a VLC video filter plugin to achive such a transformation by software.
The plugin should provide a user interface to manualy drag the source-to-target quadruple.
The plugin may implement projective maping (warping) or DirectX/OpenGL polygon based texture mapping or a target-to-source look up table.
Thank you!