I didn't see the Canon HV10A listed as a supported camcorder in Apple's list. Here's the link for you to check it out in case I missed it. If it is a tape based camera it still could be supported even though not listed.
https://support.apple.com/en-us/HT204202#canon
Sometimes if you can actually start up the camera to get it running before importing, that will trigger recognition. If you can get camera recognition, try importing into the Photos app and accessing your videos in iMovie from the Photos item in the iMovie sidebar. Or, you can try using the Image Capture on your Mac to import the videos to your desktop and from there drag them into the timeline of an iMovie project.
A major cause of camera recognition failure is defective cable or adapters. A tape based camera uses firewire cable. Here's a link that describes the procedure for connect up a tape based camcorder to a Mac:
https://help.apple.com/imovie/mac/10.1/#/mov6af9c94c1
File based cameras use USB cable. Here's a link that describes the process:
https://help.apple.com/imovie/mac/10.1/#/movbc953953e
-- Rich