Quick feet and travel violation

[gojeremy]

1st year official looking for advice again. Hard to describe but a player on top of the key makes a drive to the basket. It seems as though the feet start moving right as or just before the dribble is initiated. It looks like a travel but it happens so fast I'm not always positive. I see this a lot and I'm never sure what to call. I hope everyone understands what I'm trying to describe.