Originally published at: https://tidbits.com/2018/08/16/tipbits-make-imovie-output-full-resolution-video/
Is your iMovie output stuck at 720p, even though you fed it a higher resolution video? While trying to record a screencast from a 27-inch Retina iMac, Josh Centers discovered the fix.
Great tip, Josh. And it’s sad that the Apple Support article is a year and ½ old, implying that no one one the iMovie team has been tasked with actually giving iMovie a more user friendly way of enabling 4K iMovie output!
These days Apple software people are focussed on doing emojis and the like. There’s probably nobody in the iMovie team these days.
This really sounds like a preference that is being stashed somewhere. I’ve scoured my Mac for a likely candidate and, so far, can’t find it. I did notice that in the iMovie Library, for each project there is a “Render Files” folder. In the “High Quality Media”, if you tunnel down, there is an “Info.plist” file that contains these lines:
<key>FFSegmentStoreFileFrameCount</key>
<integer>1024</integer>
That was the resolution at which I shared my test file, which I seeded as you described. That number could be purely coincidental.
I did get a pop-up menu in the Sharing dialog that gave me a choice of three resolutions (480, 720, 1024); which it sounds like you weren’t seeing, Josh. I’m using iMovie 10.1.8, which I believe is the latest version that will run on Sierra.
It does seem like this is one of those areas where Apple went out of their way to hide functionality that they want to reserve for upselling to FCP. I use the latter 90% of the time, but find iMovie handy for that crazy-useful Map effect.
Update: I just opened the iMovie Help (who reads an app’s Help? I do) and found this:
The resolution and frame rate of your movie project are determined by the first clip you add to the timeline. iMovie now supports 4K video and frame rates higher than 30 frames per second (fps). If you want your project to be set to 4K resolution, the first clip you add to the timeline must be a 4K clip. If you want your project to be set to 60 fps, the first clip you add to the timeline must be a 60 fps clip
Seems like this item, buried at the bottom of the Create a New Movie topic, should really be called out better. And there should be a “Modify Project Settings” command that gives you more than this one-shot control over this sort of thing. (Note that there is a Project Settings popup hidden under the word “Settings” at the far right of the timeline, beneath the viewing panel [down a flight of stairs, high up on a bulletin board, behind a sign that says “Beware of the leopard!"], but you can’t change a project’s resolution and frame rate with it.)
At least Apple put the information into the built-in Help, for those few folk who delve into it.
Take a look at the plist file ~/Library/Containers/com.apple.iMovieApp/Data/Library/Preferences/com.apple.iMovieApp.plist, key CEProjectSettings. After doing the 4K video seed thing, it has three values:
- videoFormat: 4K
- videoRate: 29.97p
- videoSize: 3840x2160
Also, maybe the reason an iMac 5K screen capture doesn’t work as a seed, even if you export it as 4K, is that it is a Retina video. The 4K export is actually 3840x2180.