The most common and most likely answer to this crossword clue is the 2 plus 2 plus 4 letter word LA LA LAND
L
A
L
A
L
A
N
D
Buddy explains!

The straight part
We know that "Stuttering advice to catch/hit film (2,2,4)" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case stuttering advice to catch/hit film (2,2,4) = la la land.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.