Valentí began his career in the field of philosophy and the arts, where he scored great success in major capitals in Europe and Asia with installation and video art shows. In 1996 he co-founded the production company Los Sueños de la Hormiga Roja. He has produced nine full length documentaries, five of which he also directed and written (amongst others: Manuel Monleon: A Scream on the Wall 2004, Si Me Quieres Escribir: Letters From the Frontline 2006 and Living on Your Feet. The Struggles of Cipriano Mera 2008).
Spain