October 20, 2012, 11:34:16 am
Hi P-L, that's not a problem - just add the Overlay Image effect to the entire movie.
Color Effect -> Overlay Image
Make sure that the image you're using is the same resolution as the video you want to render (e.g. 1920x1080) and that you save it with an alpha mask as a 32-bit TGA/BMP/TIFF.