Lost audio while converting video files in OS X 10.7.4 I was using Lion's conversion feature to change .MPG video files to a compatible format (set by OS X). The files are now viewable in QuickTime and iMovie, but the audio is completely gone. Has anyone else come across a similar issue? Would I by chance be missing a codec required to convert .MPG files correctly? Any help on this issue would be greatly appreciated. Thank you for your time.
Sounds like an issue with muxed audio. See here. Also, you might try converting them with Mpeg Streamclip, which is free software.