The home video giant is developing a set-top device for streaming films directly to TV sets and is expected to announce the offering sometime this month. The product would be an offshoot of Movielink, the online film service Blockbuster acquired last year that allows consumers to watch films licensed from the major studios on their PCs. Delivering movies to TV might be the most audacious attempt yet that Blockbuster is making to reinvent its brand as digital delivery weakens the viability of its retail footprint. But by offering a home-based alternative to its stores, Blockbuster risks cannibalizing its core brick-and-mortar business in the hope that its brand will be a force online. The device is believed to be a stand-alone product akin to Apple TV as opposed to embedding a Blockbuster-branded service in such existing devices as Microsoft's Xbox 360 or TiVo. While going it alone could give it a distinctive positioning in the crowded "over-the-top TV" marketplace, that won't come without significant investment in marketing and manufacturing, though the latter cost might be shared with a consumer electronics company that has yet to disclose its participation.