idvd dual layer discs and mkv files

Hi, idvd will not encode a film if it is over a certain amount of time. The only way round this is to use a dual layer disc. But these are expensive. Is there a way round this or can anyone suggest different software to use which is as compatable with dvd players as idvd is? Thanks

Also which software will convert mkv or mp4 to dvd as I can not get idvd to do this. I am using the latest idvd.

Many thanks.

🙂