Hoping to revitalize Hong Kong's moribund film industry, producer Wellington Fung announced the creation Wednesday of a new production company, Big Media, that he said will make 20 movies in Mandarin and Cantonese Chinese over the next five years. As the former head of Media Asia, Hong Kong's largest media conglomerate, Fung actively courted international film buyers at such industry events as the American Film Market in California and the Cannes Film Festival in France. His announcement on Wednesday was attended by numerous Hong Kong film officials.