Hi, I have read a lot about the different sound formats and that people have different preferences. When playing DVDs thru an AV receiver - Does the rec auto detect the format? Can it be changed manually? Do DVDs generally come with a number of formats? Sorry, for the basic questions, but I'm trying to get to grips with it all and have probably missed out some of the basic components that make up DVDs. If I do not know these, how should I know what equipment to get! Thanks, Mark.