There are many reasons why a file may be corrupted.
Depending on the nature of the corruption, it *may* be theoretically possible to recover the file.
I’d recommend contacting Lacie requesting if they have any freeware or shareware that may be able to recover a corrupted file.
If Lacie doesn’t offer any software, you could ask if they can recommend any suitable software.
Also, ask if Lacie can restore the file using their technical support and if they charge a fee for this service, including any freight charges to send the hard disk drive back to them.
Another option may be to search for software that offers file recovery for video files. The ones I’d try first would be those offering a free 30 day trial period; I’d recommend using a back up of the corrupted file for the software to attempt a recovery on. There are many Internet forums in which people discuss different file recovery software and these may provide useful information on other people’s experiences with recovering corrupted video files.
I have had personal experience with some file recovery software on video and non video corrupted files; some software works well with recovering non video files and fail with video files. The reason is that video files are compressed and if the key information is lost, it may not be possible to recover the video file.
Nothing is lost by trying if you have the time or the money.
When I back up video files I back them onto a laptop hard drive and an external archive drive, and I keep several SD cards on hand to avoid formatting SD cards too soon, so as to have the opportunity to recopy a corrupted video file, if I only do one back up and the file gets corrupted in the hard disk drive. I only reformat an SD card once I have checked all the back up copies play properly using two different video players one on, say Quicktime and the other in the video editing software.
The last resort option, is to re-shoot the interview, if you’re not imposing too much on the interviewee’s time; one way to do this may be to think of new follow up questions based on your recollection of their answers and include them with the “old” questions. If the material needs to be updated due to changing circumstances this may provide a good reason to include the follow up questions. Rework the old questions to bring out fresh material.
Sometimes people may be willing to re-do an interview if they felt the first time they answered questions they reflected on their answers afterwards and didn’t think they answered some questions too well.
If you need to re-shoot the interview contact the interviewee and if you feel comfortable tell them you’ve had a technical glitch, most people are reasonable and those who use technology are well aware from their own experience of the problems. Ask them if they’d like to receive a copy of the questions, including the new follow up questions, to help them prepare their answers.
If the interviewee agrees to re-shoot the interview at their convenience, mention that you’ve reviewed your file back up procedures to make sure your organization will do everything humanly possible this second time to make sure the video files are backed up and checked.
If your organization’s resources allow, have a third camera running during the interview, to shoot from a third angle, to provide a back up file, in case a video file gets corrupted in one of the other cameras.
Another idea, if you haven’t already done so, use a separate audio recorder and if the video file gets corrupted, you may at least use the audio with illustrative video footage and possibly still images of the interviewee shot at different times, as another interview salvaging option.
The above measures would demonstrate to the interviewee, a good professional approach to re-shooting an interview, by helping them feel their time is valued.