Can't import .mpg or .avi files into iMovie

So I'm trying to import .mpg and .avi files from my windows box into iMovie, and it won't let me. The files are grayed out in the import window... it doesn't recognize them as movies. If I try to play them back in quicktime, the .mpg file throws a "this is not a movie file" error and the .avi plays back with audio only.

Both files play fine on the PC, and both can be imported into movie maker. Any ideas?

I think this is to do with the fact that Imovie and quicktime don't support Mpeg 2 unless you download the Mpeg 2 playback software see here

I have about the same problem. I can play a .mov files in quicktime but it´s impossible to import either to Imovie or Iphoto. It answers unknown fileformat. the codecs in the file are μ-Law 2:1, MPEG-4 Video. I have macOs Lion and the camera is GE 840s. On my Olympus it worked perfect

Thanks for posting the codecs of the movie file. I suspect the problem is the audio codec, try exporting that using, say, MP3 as the audio codec and see if that doesn't clear up the issue.