Dijkgraaf - 11:10 pm on Jul 31, 2012 (gmt 0)
I did a search for USB foot pedal VLC "Linux"
The first few links were either your posting elsewhere or unhelpful, but after that there was a link leading to software that may solve your problem (at a cost).
"It makes USB transcription foot pedals compatible with VLC Media Player." with a link to
It's classed as Shareware but costs $49.99