Time Warner Cable is launching an iPad application that plays live TV, becoming the first cable company to do so. The app will be free to download on Tuesday morning, but it will only work for people who subscribe to both video and Internet service from the New York-based cable company. Even then, it only works in the home, when the iPad is connected to the company's cable modem via a Wi-Fi router.

Rob Marcus, the company's chief operating officer and president, said the app will play 30 basic cable channels in high definition to start, but that number should expand soon.

"For all intents and purposes ... this enables you to convert any room in a house into a TV room," Marcus said.

Other major cable companies have iPad apps that play video on demand or act like big remotes. Comcast Corp., the largest, has promised that its app will play live TV before the end of the year. Cablevision Systems Corp. has said it will have one even sooner.

Time Warner Cable's app doesn't work as a remote control, nor does it give access to video on demand or shows stored on a digital video recorder in the home. Marcus said these features will be added later. He also said laptops, smart phones and smart TVs could all eventually get apps, too.

Companies such as Netflix Inc. and Hulu Inc. already have apps that stream movies and TV shows to the iPad, bypassing, in some respects, cable companies. However, the apps don't show live TV.

Some people have started cancelling cable in favor of Internet viewing, but the numbers appear to be small so far.

"Increasingly, customers want more flexibility in the way they view content, whether that's on different devices or in different rooms of the house," Marcus said.

Time Warner Cable has 12.4 million video subscribers, making it the second-largest cable company in the U.S. and the fourth-largest pay-TV company, behind Comcast and satellite companies DirecTV Group Inc. and Dish Network Corp.

A device called the Slingbox, which connects to a cable or satellite set-top box, has for years let pay-TV subscribers watch their TV channels through an Internet connection. There's an iPad app that lets them receive the picture on an iPad as well. The maker of the Slingbox is now Dish Network, which has also built the "slinging" capability into a high-end set-top box.

The Slingbox and Time Warner Cable's system work very differently. The Slingbox "reads" the TV signal in the subscriber's home and sends it out on the Internet. Time Warner Cable, meanwhile, broadcasts the TV signal over the Internet into subscribers' homes.