While the advection plugins are supposed to work on any source, we strongly recommend to work with sequences which number of frames is a multiple of 30. Due to approximations, some offsets can occur with sequences that don't meet this requirement.

Furthermore, when computing optical flux with the AfterEffect plugin, we need to foresee one frame more at the beginning and at the end of the sequence as the optical flow is computed using the frame before in forword sense and the frame after in reverse one (then first and last frame of the video won't appear in the optical flow).

So to sum up:

sequence frames nb = n*30 (+2 if optical flow is computed with our plugin in AfterEffect)

Our example is Cube.mov, 242 frames.