This is an archived article that was published on sltrib.com in 2012, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.

Movie lovers with stacks of DVDs and Blu-ray discs may often wonder, "Wouldn't it be great if I could watch these on the go whenever I want?"

Only recently has Hollywood made some DVDs and Blu-rays available with an included "digital copy" for mobile devices.

But what about all those older movies you have lying around? How can you watch them on the go without having to purchase them again?

Retail chain Walmart recently introduced a "Disc to Digital" program that allows you to take a DVD or Blu-ray you own and unlock a digital streaming version so you can play it on a mobile device such as an iPhone or iPad.

You bring the disc in and, for a small fee, a clerk can unlock the movie in its digital form. I took several movies to my local Walmart to test the service.

The process is easy. It's all done through a movie streaming service Walmart owns called Vudu.

You sign up for an account on www.vudu.com">http://www.vudu.com, where you look to see if the movies you own are among those that can be unlocked. If they are, you choose if you want a standard or high-definition version. Then print the list of movies and take it to Walmart, along with the discs of those films. The site also shows you which Walmart stores in your area participate.

The clerk at the Walmart photo lab will look at your list and stack of discs to confirm you own those movies and then check them off on a store computer that's connected to the Vudu service. Those digital versions are then unlocked and tied to your Vudu account.

Because you can unlock only one copy of the movie per DVD or Blu-ray, the clerk then stamps a small logo around the spindle of the disc so it can never be used again to unlock a digital version. This is to prevent someone from using the same disc to unlock multiple digital copies for other people.

A stack of 15 movies took the clerk only about 15 to 20 minutes to authorize. Nothing is actually converted from the disc (which is illegal because that requires breaking the disc's copy protection). The clerk is simply telling the Vudu service that the digital versions of those movies are available for streaming under your account.

About 10 minutes later, you'll be able watch those movies on your smartphone or tablet, either through your mobile Web browser or by downloading a Vudu movie player app (which is available only for the iPhone and iPad but not Android phones).

The price is reasonable. It costs $2 to convert a DVD or Blu-ray to a standard-definition file and $5 to unlock the HD version from a DVD. Standard-def versions are what play on mobile devices.

The streaming versions look clear and crisp, and they stream well as long as you have a decent Internet connection. Just don't use your phone's 3G or 4G data connection too much or you will reach your data cap in a hurry.

There are some hiccups. For some reason, TV shows are not available. Also, one film gave me the theatrical version while it said the "director's cut" was the one available. And a few customers have complained on forums that some movies were in the wrong aspect ratio (the screen dimensions) from what the movie was actually filmed in (though I didn't have that problem). Also, when you stop playing a movie, the file fails to remember where you stopped, an annoying problem.

Finally, the biggest concern about the service is that the digital versions of the movies are converted to what's called Ultraviolet copies, a new format of digital movie files that Hollywood is adopting. The problem is that the Ultraviolet system is confusing, has compatibility problems and is difficult to control. The movies you unlock on Vudu, for example, should also show up in a separate Ultraviolet account. In my case, they did not.

But if you ignore those growing pains, Walmart's "Disc to Digital" program is inexpensive and gives you a new way to view your movie collection on the go.

Google+: +Vincent Horiuchi