It always comes down to porn.

Sony’s Blu-ray format may have a greater percentage of Hollywood studios on board — everyone but Universal, really, and that’s only a matter of time — but it appears the adult film industry has other plans.

According to Fleshbot, dirty-movie distributor Digital Playground has just switched its affiliation to Toshiba’s HD-DVD platform after initially releasing some titles to Blu-ray. (Another distributor, Wicked Pictures, sided with HD-DVD from the start.)

The decision makes some sense, since HD-DVD allows for combo discs with a standard DVD side — a good way for a company to hedge its bets as consumers move hesitantly into the high-def field — and it also avoids the inevitable bad publicity when some child finds Daddy’s grown-up movie in the family PS3.

It’ll be interesting to see how (or if) this affects HD-DVD player sales; personally, I have to wonder whether there’s really a demand for high-definition porn in the first place. I mean, the whole point of pornography is an idealized representation of sex … does that include being able to see Tera Patrick’s razor burn?

Of course, the format war is awfully close to being a moot issue: Engadget reports that LG’s high-def combo player will ship early next month.