I am working on a computer vision project where I will setup a camcorder in a room at around 6am and record people as they walk around and interact with things. The recording ends at 11pm. The room itself is huge (~50 ft tall) and I need to mount the camera either on the ceiling or on one of the rafters, so I'd prefer not to have to fetch an SD card at the end of each day if at all avoidable. The people are not moving super fast, but I will be doing motion analysis based on an image of the empty room, so it's important that the video be uncompressed (compression changes pixels and messes up the before/after diff for the motion tracking). Also, the people will be interested in viewing their actions later, so it needs to be in color and preferably HD. There is likely to be minor vibrations, so it also needs to be able to stabilize the video, though I imagine that is standard nowadays.
Given those requirements, does anyone have any recommendations for a camcorder? I'm looking in the sub-$400 range if at all possible.
Edit: Compressed video is fine after all. I was misunderstanding what kind of video my test data was using, but it seems to be compressed, so I can handle that. Also, if possible I'd like the camera to be able to just stream the video to a server on a local network so I can store it offline without having to retrieve the SD card.
Edit 2: After some more looking, it does seem like there are 30M (~64ft) active USB extension cables. So it's possible that I could run a cable to a laptop on the ground and not need to worry about power or SD storage. As a result, I'm currently leaning towards an HD webcam like AJ suggested.