How did you get the audio/atc to record in the video?
I bought a patch cable from
www.aircraftpatchcord.com and also bought a digital recorder. After the flight, I download the ATC recording from the digital recorder and sync it up with the video. Total cost was less then $80.00
Syncing is very easy especially for landing, since I can hear the stall horn on the camera so I match the two together. For enroute, I just talk out a "prompt - camera on" so I know to look for a video within the audio track.
My camera does not have an audio in so I had to go this route, which for me is preferred since I can simulate what it really sounds like in the plane and the ability to hear power changes in the engine especially on my instrument approaches.
Using the audio in on a video camera, one doesn't get to hear the engine noise.