Error in video files copied from FAT32 external drive to Mac OS

hi,
i have problem there are large number of video files in an old FAT32 drive and I copied to a new one formatted in Mac OS Extended in order to reformat the old one.this video files are converted in to .mov and .av1,all the big video files I had created directly onto the old drive,because of limited file size in FAT32.but the problem is when i try to open file it says unable to open,What has happened and what is the solution?Can anyone help!!!

I don't think that should matter. iMovie breaks all video files into approx 1gig incraments. I believe this depends on how the movie was created. If importing from a digicam via DV, that is true for iMovie 5 (but not iMovie 4 I don't believe). I know that I converted an mpeg file to DV and editied it in iMove 5, and the resulting DV file from iMove iwas 21GB in length. When I tried to copy this file to a FAT32 disk it stalled (but no error message). This can be confusing. I would sugges checking the sizes of the files that you want to backup; if any of the files is >4GB, the FAT32 won't work and you will have to use HFS.

In other words there is some discrepancy with the file's size or end-of-file marker, or some variation on this. This sounds like a read error not a write one i.e the problem lies with the original file.

Now, you may ask, "How do I make it HFS+?"...

You would have to reformat the drive to change the formatting to HFS+ (Extended).

Backup anything you can't replace on that disk, then use Disk Utility in your Utility folder to reformat the disk.