Some cameras (in my case a sony digital still camera) record video in a format that is incompatible with iMovie. The clip imports into iMovie just fine, but there is no audio. I did some internet surfing and found this is because the file is muxed which means the audio and video are intermixed and for some reason, iMovie does not like this. The solution is convert the file to a different format. The best program I found is MPEG Streamclip. It is a free download and is easy and efficient to use. Here is what to do to fix the no audio problem:
- Download and install MPEG Streamclip
- Open Streamclip
- Import your video file by using 'file' - 'import' or drag the file from your finder to the Streamclip window.
- Select 'file - 'import to Quicktime' - you will be given a chance to name the file and select a destination.
- That's all - you're done!
Now you can import and edit the new Quicktime file.