The ClearPlay system uses a set of programmed commands tailored to about 500 individual movies released on DVD. Not all movies are available, and Aho said ClearPlay won't even try if filtering would ruin the film.

The commands tell the DVD player when to mute dialogue or skip segments that show 14 levels of violence, sex, nudity and profanity. The user can pick which filters to activate.

In "Terminator 3: Rise of the Machines," for example, the filter shows the title character — played by Arnold Schwarzenegger — squatting naked in the desert and starting to stand up, but cuts to a shot of him already standing and seen only from the chest up.

A team of ClearPlay employees screens films, which can be selected by the DVD owner. The directors and movie studios have argued that the ClearPlay system allows people who are not necessarily qualified to edit their films.

Aho responded, "The guys doing this are movie guys who have a passion for movies like nothing I'd ever seen. We think it's presumptive of the directors to want to follow movies into the home."