FLV Help

Hi Guys/Gals,

Looking at the following website: http://www.ten4design.co.uk/ I was wondering the best way to go about creating a similar video effect. I have a background avi which i can convert to flv and i have the coding sorted. Just not too sure how to go about giving my video a horzontal pattern sort of effect.

Will this be done using After Effects or something similar, and if so, does anyone know of any relevant tutorials?