Seth MacFarlane’s legions of fans might be left shaking their heads after watching Ted, his live-action debut as a feature filmmaker.

MacFarlane is the creator of no fewer than three current prime-time animated sitcoms including the venerable “Family Guy.” In Ted, he employs much of the same sense of humor from those shows, a mix of raunchy low-brow slapstick and edgy satire. He even offers fans various inside jokes, as well as some of the adults-only language and nudity that network TV doesn’t permit, and uses some of the same cast members and writers.

One of the gags makes reference to Ted, the anthropomorphic stuffed bear in the film, sounding like Peter Griffin, the “Family Guy” protagonist. They do sound alike, and they should — MacFarlane does the voice for both.

Add it all up, and perhaps MacFarlane would have been better off just creating a “Family Guy” feature. It worked for “The Simpsons,” another prime-time animated staple, and probably would have translated better to the big screen than this thinly sketched comedy of arrested development.

The film is set in Boston, where John (Mark Wahlberg) shares an apartment with his childhood companion, a beloved teddy bear that came to life as a result of a childhood wish. Thirty years later, the cuteness has worn off but the loyalty remains, something that threatens to drive a wedge between John and his forgiving girlfriend (Mila Kunis).

The script has a hit-and-miss irreverence that relies too heavily on its central gimmick, namely the sight of a cuddly plush bear that spouts vulgarities and parties too hard. Like most of the film, that’s amusing for a while before becoming sophomoric and tedious.

There are plenty of solid laughs from some clever non sequiturs (also following in the “Family Guy vein) as well as a recurring gag about Ted’s employment in a supermarket.

Yet in the second half, the film detours into a silly attempted kidnapping plot involving a sadistic father (Giovanni Ribisi), and the corresponding attempts at poignancy seem out of MacFarlane’s element.

The film deserves credit, however, for its seamless rendering of Ted through the use of computer-generated effects. It’s an impressive technological achievement.

The filmmaker has already established himself as a powerhouse in television, and it seems likely that his unique comic sensibilities will eventually translate to movies. Perhaps MacFarlane’s next project will better realize his potential.

Rated R, 106 minutes.