Based on noted film producer Art Linson’s memoir, this comedy drama satirises the inner workings of Hollywood, as seen through the eyes of a middle-aged producer suffering a crisis of confidence.

If Linson’s book is as toothless and meandering as his fictionalised screenplay, it’s hard to see how this insider’s view of the industry made the bestsellers’ list.

He paints studio heads as money-grabbers who strangle artistic freedom to wring another dollar out of thrill-seeking audiences.

That’s hardly a revelation, nor is the depiction of one Hollywood star as a bully on a massive ego-trip.

Cameos from Sean Penn and Bruce Willis, both playing themselves, fall flat, the latter locked in a tug of war with the financiers over an effusive beard.

To shave or not to shave, that is the trivial question.

When he’s not locked in a tug of war over his hirsute leading man, producer Ben (De Niro) is embroiled in couples’ separation therapy with ex-wife Kelly (Robin Wright Penn), who he still loves.

He tries to win Kelly back and to bond with teenage daughter Zoe (Kristen Stewart), but work invariably gets in the way, including a war of words with studio chief Lou (Catherine Keener) over the gangster flick Fiercely, which is due to open the Cannes Film Festival.

The film’s controversial ending, which sees the hero’s dog take a bullet to the head in lurid close-up, proves a sticking point; a shock to the system which Ben likens to the audience taking their kids to Disneyland and seeing “Mickey Mouse douse himself in gasoline and set himself on fire.”

Somehow, the producer must persuade Fiercely’s drug-addled director Jeremy (Michael Wincott) to re-cut his masterpiece.

Meanwhile writer Scott (Stanley Tucci), who Bob suspects may be sleeping with Kelly, pitches a script starring Brad Pitt as a florist, which he describes effusively as, “the Rose Bowl Parade meets The Da Vinci Code”.

Bob is going to need all of the luck in the world to survive these two weeks.

What Just Happened? might well be the response of audiences who fall asleep during Barry Levinson’s film and wake with a start to the sounds of gun fire and a whimpering pooch.

There are a few chuckles but no laugh-out-loud moments as De Niro’s world weary middleman clings to the last vestiges of his sanity, including a funeral with the obligatory shot of a mourner falling on to the coffin.

The narrative is separated into slow-paced daily chapters, marking the progress of Fiercely from its disastrous test screening to the premiere at Cannes where Jeremy takes great delight in sticking two fingers up at Hollywood.

We simply yawn and look at our watches, counting down the minutes until the end credits roll.

They don’t come soon enough.