Record for writing and working on film is giving someone a bad name (12)

'giving someone a bad name' is the definition.
I can't tell whether this definition defines the answer.

'record for writing and working on film' is the wordplay.
'record' becomes 'disc' ('disc' can be a synonym of 'record').
'for' is a charade indicator (letters next to each other).
'writing' becomes 'r' (I've seen this in other clues).
'and' says to put letters next to each other.
'working on film' becomes 'editing' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'disc'+'r'+'editing'='DISCREDITING'

'is' is the link.

Can you help me to learn more?