(CNN) Eddie Murphy hasn't exactly been dormant since his Oscar-nominated role in "Dreamgirls," but he's been quiet enough for "Dolemite is My Name" to be billed as the start of a comeback. If so, it's a mildly diverting, sluggishly paced kickoff, one predicated on the hardscrabble underbelly of show business.

Directed by Craig Brewer ("Hustle & Flow"), the most salient credit in framing the film actually belongs to writers Scott Alexander and Larry Karaszewski. That's because their credits include the semi-classic "Ed Wood," Tim Burton's ode to the schlock director, a similarly pitched period pieces that also focused on a guy laboring to produce low-budget movies while surrounded by colorful but quirky characters.

In this case, the persistent dreamer in question is comedian/singer Rudy Ray Moore, whose hopes of achieving stardom haven't gone as planned. Instead, all the hard work and pitching has merely landed him an assistant manager job at a record store in the early 1970s and whatever emcee gigs he can muster at local clubs.

"How'd my life get so damn small?" the usually upbeat Moore muses at a low point, before stumbling upon the idea of developing a character around the crude comedy associated with an urban toast about a foul-mouthed pimp, Dolemite, whose rhyming patter served as an inspiration for early rap.

The movie essentially breaks into two parts, with Murphy's Rudy first developing Dolemite and seeking to sell the material, running into roadblocks because of its raunchiness before peddling albums out of his car trunk; and then repeating that process, too extensively, when he decides the real money would be in reels -- producing and starring in a Dolemite movie, even though he knows virtually nothing about the process.

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