The question is whether k9copy without MEncoder is useful? We could move mencoder to Recommends or set variant dependency "mencoder | libav-tools". But the question is whether it will be useful without rewrite k9copy to able use avconv instead of mencoder?
Basically mencoder is no longer supported in Debian, but it seems it is still available under Ubuntu (at least until Trusty). I think an easy solution is to add mencoder to the list of dependency packages that we maintain and leave everything else as is at the moment. Cheers Michele