The story of how Rupert Murdoch is attempting to revolutionise the world’s video-rental industry is becoming clearer with a new story by Edward Jay Epstein on Slate.com. Murdoch plans to digitally deliver movies and other programming from his satellites to 20 million home digital video recorders he plans to give his customers.

“There’s just one catch,” explains Slate. “To make digital video on demand work, Murdoch would have to overcome a formidable barrier—the 45-day head start that video stores have been given.” This is the so-called “video window” where moview studios delay the electronic delivery of movies for at least six weeks after video stores have had the opportunity to rent them.

And the problem with trying to get rid of the “video window” is – in a word – Wal-Mart, the single biggest seller of DVDs in the world which has threatened that any studio which does away with the 45-day video window for a single title would risk losing access to Wal-Mart’s incredibly valuable shelf space for all of its DVDs.

“But Murdoch, who famously crushed the British newspaper unions, is not one to bend to pressure from a retailer even as powerful as Wal-Mart,” explains Epstein. “My bet is that Murdoch will succeed, creating a vast new video-on-demand market, qualifying him (once again) as a master of the universe – or at least of New Hollywood’s universe.”