It’s a familiar trade-off to anyone who has tried cutting the cord: While streaming services such as Netflix and Hulu often deliver access to on-demand video anytime and on screens of any size, traditional cable channels are largely locked to a home set-top box.

Third-party set-top boxes from companies such as TiVO or Fire TV from Amazon haven’t been able to get easy access to cable content. But now, a major push to change that is sparking a policy fight in Washington involving some of America’s biggest companies, including Google and Comcast. The outcome could define how Americans watch television shows for years to come.

On one side, cable companies want consumers to get cable or satellite TV channels through their set-top boxes or through mobile device apps that they design and control. These apps deliver a similar lineup as the ordinary cable or satellite set-top box. Everything looks and feels just as though you were browsing channels the traditional way.

Cable operators say they exert such tight control over such content to honor their complicated contracts with film and TV creators. At the same time, they argue, their apps address the new ways consumers want to watch shows.

“It’s a pretty simple issue,” said Brian Dietz, a spokesman for the National Cable and Telecommunications Association (NCTA), a top Washington trade group for cable companies. “It boils down to the direction the marketplace is already going — versus some people who want to change that.”

But critics of this arrangement, including consumer advocates and tech companies, want more freedom to present TV programming that is far more consumer friendly and doesn’t feel so tied to a cable company.

They envision being able to deliver television content with a different layout and interface depending on whether the shows are being watched on a smartphone or a big-screen television. Apple TV might present a channel lineup differently from Amazon’s Fire TV, which might have different viewing or browsing features from TiVo. The concept would allow companies to reformat television lineups while not completely wresting control away from cable and satellite companies.

That’s way better for consumers, Google argues, especially compared with the current system in which consumers are forced to lease “technologically stunted” set-top boxes. Google and other advocates are urging the Federal Communications Commission to adopt rules requiring cable and satellite companies to open up their content to other set-top box makers. While the FCC is a long way from making any decisions, the agency is collecting comments on the issue.

But cable and satellite companies say the proposal from tech firms and consumer advocates is a pipe dream. Implementing it would require huge, unnecessary investments in regulations and technology to protect the content and copyrights, they argue. Comcast wrote that such a system could be “vulnerable to hackers.” The NCTA has said such proposals would be akin to letting Hulu deliver content produced by Netflix.

At the center of the fight is Hollywood, whose films and TV shows stand to be powerfully affected by any decision the FCC makes. For now, it is warning that opening up TV shows to new formats would be bad for business and possibly even unconstitutional.

“Third-parties could potentially seek to disassemble the programming, features, and functions offered over distribution services and selectively reassemble some of them for their own commercial exploitation,” the Motion Picture Association of America wrote in a filing. “This could interfere with contracts, upset copyright law, and run afoul of the First and Fifth Amendments to the U.S. Constitution.”

But what worries the film industry is almost precisely what others view as a potential benefit.

“Retail competition involves more than simply viewing video programming on different screens,” wrote TiVo in a filing. “It involves innovative user interfaces, search functions, and so on that give consumers greater choice and an enhanced user experience — a true alternative to what is provided by the operator.”