I hate to be the bringer of bad news, but unfortunately what you want
to do seems to be impossible currently.
iMovie is designed to edit DV25 (25Megabit Digitial Video) format
only. The IP5 that you have uses a version of MPEG-2 that is unique to
Sony. Due to the huge differences in the type of information that
comprises each type of video, DV software (such as iMovie, Adobe
Premiere and Avid FreeDV) is unable to capture from your camera.
From what I have read it seems that the IP5 is not really functional
with Macs, as the Sony-supplied application Movieshaker is Windows
only. I did read one comment that seemed to suggest that Movieshaker
was also available for Macs, but I have found no evidence to back that
If you are able to download the video with some Sony-supplied
software, you should be able to convert it, however you will need
Quicktime Pro. This process is roughly explained in this forum post:
However, even if you do convert it, and are able to edit it, you will
probably not be able to put it back on the camera.
Other editing applications that support MicroMV format are
PinacleSystems Studio, and Ulead VideoStudio - both PC only.
There is a petition to Sony to make MicroMV work on the Mac:
...there are a few hundred others having the same problem as you.
And as a epilogue, it seems Sony is dumping the MicroMV format:
For more information have a look at these articles I found by
searching for various combinations of the following terms:
Vaio Village Forums: MicroMV Video Format
TechTV | First Look: Sony's DCR-IP5 and DCR-IP7BT Camcorders
Video Buyers Guide: Sony MicroMV
Manifest Technology: Sony MicroMV
Comments about the MicroMV format at joi.ito.com
MicroMV discussion at ComputerVideo forums
Sorry I can't provide any better news, but hopefully these links at
least clear up the issue for you, sadly without providing a solution.