Available on DVD: “Sleepwalk With Me”

It takes a kind of crazy tenacity for an aspiring stand-up comedian to endure the grubby humiliations of life on the bottom rung of the professional ladder. Watching Matt Pandamiglio, the jocular, slightly schlubby alter ego of the comic performer and writer Mike Birbiglia, take his act on the road in Sleepwalk With Me is like observing an out-of-shape military recruit stumbling through the first week of boot camp. Survival depends less on talent than on having a thick enough skin to recover after every setback and still maintain a facade of genial equanimity.

Matt’s ordeal is not as excruciating as you might expect because he is unflappable and reasonably good-humored even in the worst of times. Before his road trip he works as a bartender in a New York comedy club, where he is seldom allowed to test his skills.

Despite scant evidence of significant talent in his early performances, which rely on flat jokes that elicit more groans than giggles, he refuses to give up. The first time he earns genuine laughs is when he muses out loud about his troubled relationship with Abby (Lauren Ambrose), his loyal, supportive live-in girlfriend of eight years.

Suddenly he connects with an audience on a human level. But that involves betraying his relationship by dismissing it. His remark — "I decided I’m not going to get married until I’m sure that nothing else good can happen in my life" — is not an encouraging sign for the couple’s future happiness.

This small, likable movie, which Birbiglia adapted from his 2008 one-man show with the producer Ira Glass (This American Life), Joe Birbiglia (his brother) and Seth Barrish, is several things loosely wound together by Matt’s breezy narration directly to the camera.

It is an unvarnished portrait of the kill-or-be-killed stand-up comedy world’s lower echelon, in which paying dues means driving from gig to gig for meager wages in places that are nearly empty or are home to crowds that subject the performer to brutal heckling.

It is also the story of a relationship that deteriorates as Matt’s ambition outweighs his uncertain commitment to Abby, who demonstrates extraordinary tolerance for his childishness and reluctance to marry. Beautiful, smart, funny and empathetic, Abby is about as good as it gets. And Ambrose infuses her with a warmer, more mature version of the sensitivity that she brought to Claire Fisher, her character in the much missed HBO series Six Feet Under.

The strangest thread of the movie has to do with Matt’s worsening sleep disorder, brought on by relationship anxiety, which he refuses to deal with until it endangers his safety. He has weird dreams during which he walks in his sleep. In the most perilous somnambulistic misadventure he hurts himself jumping from a second-story hotel window.

These episodes, some staged as surreal dream sequences, inject this otherwise prosaic-looking movie with a visual pizazz that makes Sleepwalk With Me more than just a glorified stand-up act.