I have a set of six XviD .avi files. One of them is larger than the others. I converted them all to h.264 .m4v files with Handbrake, then tried to import them into iMovie directly.

Five of the files it copied over perfectly. The large one, however, it insists on transcoding to a .mov file using the Apple Intermediate Codec (which is more highly preferred for editing than h.264).

THE PROBLEM: When both types of files — h.264 and AIC — appear in an iMovie Event, the thumbnails in the Event Browser do not show up; all video files are displayed as blank gray filmstrips.

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The thumbnails themselves are not corrupted; they are generated correctly. Deleting the thumbnails and the cache and having iMovie rebuild them does not help. They are simply not being displayed.

Even if I ask iMovie to go ahead and transcode the five smaller files, it refuses to; it copies them over as-is.

Even if I ask iMovie to NOT transcode the larger file, it refuses not to; it always transcodes it anyway.

I've seen recommendations to use several different "iMovie converter" apps, but they all seem like scammy crapware.

So what I need is one of the following four things, ordered from most to least preferable:

  1. A way to make iMovie display video thumbnails when mixing h.264 and AIC video in the same event
  2. A way to make iMovie directly import the larger .m4v h.264 file that it currently insists on transcoding
  3. A way to make iMovie transcode h.264 video even when it can import it directly
  4. A good, decent, usable, reliable, non-scammy third-party app that I can use to transcode (as many different kinds as possible of) video files into something iMovie prefers to use directly.
  • Maybe this will help: iMovie doesn't like to edit in compressed formats (h.264, AIC, etc...) so when you import video, it decompresses all of it. I don't know a good way around this. The reason it does this is editing compressed files puts a lot of strain on your CPU. (due to the decompression required)
    – spudwaffle
    Nov 27, 2011 at 6:58
  • @spudwaffle That's part of my point, though. It doesn't decompress five of the h.264 files I'm using. It brings them in directly, gladly and without complaint. In fact, even if I ask it to transcode them (by checking the Optimize checkbox), it won't do it. And I thought AIC was one of the preferred codecs for editing (hence its name as an "Intermediate" codec)? Nov 27, 2011 at 20:20
  • So what's the problem? iMovie is a consumer-level app and is not designed to give the user much control over technical details. As long as you can edit your video smoothly, you shouldn't have to worry about compression.
    – spudwaffle
    Nov 27, 2011 at 21:02
  • @spudwaffle The problem is that when the two kinds of video are in the same Event, all videos in that event are shown as blank gray filmstrips without thumbnails, so I can't see anything without scrubbing over every inch of every video. I'll edit the question to better indicate the real problem here. Nov 27, 2011 at 21:28

3 Answers 3


Answer for point 4:

  • The DivX converter looks like it converts to DivX but not from DivX. MPEG Streamclip is horrible and always gives me an error when I try to use it. QuickTime Pro is a good idea, and in fact QuickTime Player X looks like it will do it, too; my only quibble is that if you add tell it to convert six movies, it does them all at the same time, rather than as a one-at-a-time queue. But if no other answer turns up anything better I'll be back to accept this one. Nov 28, 2011 at 5:28

Use Automator to make an application that transcodes file you feed into it.

1: Make a new Automator application. New automator application

2: Add the Encode Media action and choose the appropriate settings for your clips. Encode media

3: Save the app somewhere.


4: Then, drag the clips into the application you created.


The encoded versions, ready to throw into iMovie, should show up in the same directory as the original clips.

  • I never think of Automator, and then when I try to use it I always remember why. I get the error described in this thread whenever I try to use that Automator app with a file of any type. Nov 28, 2011 at 5:03
  • Anyway, that's just a different UI over QuickTime… Won't change the base of the problem. If you can resolve to Automator, you might as well use QuickTime > Export and avoid the (minor, admittedly) hassle of creating a process.
    – MattiSG
    Nov 28, 2011 at 6:30

At long last, I found a conversion app that seems to not make iMovie throw up all over itself. It's called iVI (Mac App Store link). It's not the prettiest Mac app ever written, but it's not as bad as a lot of apps in this category, and it works wonderfully.

iMovie still insists on transcoding some of the files it generates, but thumbnails now render almost flawlessly; occasionally one video in the project will be gray, but it's consistently, unglitchily gray. I'm calling this good enough to declare victory.

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