Hi Rich. Thanks for your detailed reply but neither of those options worked. In both cases, creating a new library, reloading the videos from my hard drive... all produce the same popping noises. It's interesting that they seem to appear in the same spot although I haven't tested that exactly.
As another possibility, I purchased Final Cut Pro assuming that would fix this problem. It did not! I get the same pops in Final Cut Pro. Then I spent most of yesterday downloading trial versions of MANY other video editors that work on Macs (Adobe Premier, Movavi, Wondershare Filmore9, MovieMator, Lightworks). NONE of them have these pops!!!! I also confirmed over and over that there are no pops in the raw videos by playing the movies in Quicktime...
As a last resort, just now I tried using iMovie on my MacBook Pro. (The problems above occurred on my iMac desktop.) I find exactly the same problem with pops on my laptop!! This is the first time I ever used iMovie on my laptop so it can't be anything with settings. All of this makes me think the problem is unique to Apple and the codec or something that they are using...
If you have other suggestions, please let me know. Otherwise, it looks like I'll be moving on to some non-Apple editing software.
