Just one video clip turns black when played in iMovie timeline

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Level 1

18 points

Just one video clip turns black when played in iMovie timeline

I've imported several mp4 video clips into iMovie from my computer. After arranging them in the timeline, one clip begins normally but after a few seconds goes black for its duration. This happens with none of the other clips. The clip, which is one-minute long, plays normally in the My Media area, but when it's added to the timeline, it runs black most of its length.

All the clips were taken with the same device (a drone) and imported to my iMac from the same SD card.

To try to fix the problem, I've deleted the clip from timeline and from the media area. I've reimported it from Finder via the import media option. I've added it to timeline both by using the + in the media clip and by dragging it. I've shut and restarted down iMovie. None of these actions have fixed the problem.

There's no way this one clip could be corrupted given the others are not, and I've tried importing it into iMovie and the timeline in multiple ways.

Given that the clips plays normally in My Media but not in the timeline, it seems like an iMovie problem. Is iMovie just horribly buggy, or is there a way to fix this?

I have iMovie 10.3.1. I'm on an iMac Late 2015. I have macOS Big Sur Version 11.6

Thanks if you can help me fix this. I'd really like to use this clip in the movie.

Posted on Jan 30, 2022 12:29 PM

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Answer 1

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Rich839

Level 8

47,250 points

Jan 31, 2022 9:17 AM in response to Skydog99

Sometimes, for some unknown reason, an issue is confined to one specific project and does not occur in other projects. The fact that your troublesome clip worked correctly in a new project would indicate that the problem was indeed project related. I suspect that it will not recur.

Regarding your observation on a different matter that deleting preferences wiped out your project, that cannot happen from deleting preferences. Something else must have been the cause. Deleting preferences does not cause loss of data. It simply restores the iMovie app to the original default settings. Nothing is done to the data or project. The data and projects reside in the iMovie library that is separate from the app. You can delete the entire iMovie app and your projects will still be intact in the iMovie library. When you redownload the iMovie app, you then can access the projects as before.

When one deletes preferences iMovie opens in a new blank library with no projects in it. To find the projects, you need to reopen iMovie in the library in which the projects were created, and they will be there. Perhaps the project that you believe was deleted is actually resting in a different library. Check to see if that might be the case.

If for some other reason you do lose a project, you may be able to find it in a previous automatic backup of your library in the iMovie Backups folder. To get to the iMovie Backups folder, follow this file path from the Finder menu:

Go/Home/Library/Containers/com.apple.iMovieApp/Data/Library/Caches/iMovieBackups

When you get there you will see a list of previous backups of your iMovie libraries Click on one dated just before your issue occurred. iMovie will open in that library. Navigate to your projects browser (where your projects are displayed as icons) and see if your projects are intact.

Since because of your previous bad experience you are worrying that deleting preferences might cause you to lose your project, you can always create a new iMovie library and copy your project to it before deleting preferences. Open both the old and new libraries and go to your projects browser (where your projects are displayed as icons). Move your cursor over the project icon to reveal a circle with dots in it to the right of the project's title. Click on the circle to reveal a drop down menu that will contain and option to copy the project to the new library.

Projects cannot exist independently of an iMovie library. They must reside in the library. If you select the library's icon and do an Edit/Copy and then Edit/Paste it in a new location you will have made a backup of all of your projects. Or you can create a new library and copy your project to it as described above.

Finally, you can keep a Time Machine backup that will allow you to restore an iMovie library to an earlier point in time to enable one to recover a corrupted or deleted project.

-- Rich

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Answer 2

Skydog99 Author

Level 1

18 points

Jan 31, 2022 2:00 PM in response to Rich839

This is very very helpful. Since the Handbrake suggestion seemed to work, I think I'm good. But I'm going to save all this info about deleting preferences, as I think I'll need to do it again someday, and I will use it make sure my Project doesn't disappear. Thanks for all your help!

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Answer 3

Rich839

Level 8

47,250 points

Jan 30, 2022 10:11 PM in response to Skydog99

To rule out iMovie as the cause:

Put the troublesome clip into a newly created project and see if it plays fine there.

If the problem still exists, then try deleting preferences. To delete preferences, open iMovie while holding down the Option and Command keys and select to delete preferences in the box that appears. iMovie will open in a new library. Reopen your old library to get back to your projects. Deleting preferences is a safe procedure that will not cause data loss or disruption to your project.

If the above doesn't solve it, it is unlikely that there is any bug with iMovie. The iMovie timeline can be a bit more sensitive to tiny rendering issues in a clip than is QuickTimePlayer or playing the clip outside of the timeline.

The likelihood is that there is some rendering issue at the point in the clip where it turns black in the timeline. You can scroll around in that area and see if you can find any sign of corruption that you can cut out. If no luck there, then re-render the movie clip with the free download Handbrake. Convert it to H.264, Mp4/AAC that Handbrake will do by default. Do that even if the codec already is indicated to be Mp4/AAC. Re-rendering often cures issues.

You can get Handbrake here:

https://handbrake.fr/

A simple way to do it is to open Handbrake and do a File/Open Source. Navigate to your video and choose it as the source from the resulting screen. Then do File/Start Encoding. Wait a couple of minutes for the conversion to complete. Then save and import the converted clip into iMovie.

-- Rich

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Answer 4

Skydog99 Author

Level 1

18 points

Jan 31, 2022 6:21 AM in response to Rich839

Thanks Rich. I tried your Handbrake idea, and it worked -- so far. That's not to say it won't go bad again, because before I had the problem with it, the clip originally worked in my timeline for awhile. Then, after I began editing, I notice the black taking over everything but the first few and last few seconds. I'll keep editing and see if the problem is gone for good, or not.

Question on deleting preferences. I did follow that advice for a different iMovie problem (I couldn't add text to titles) on a different computer (my MacBook Pro). The problem with that action is it wiped out the Project I was working on. Yes, I know that's not supposed to happen -- I talked to Apple Care, and they were puzzled. But it really and truly was gone from my hard drive (I searched everywhere).

So, if I need to delete preferences again (maybe for the current problem), can you advise on how to 100% save my Projects, so if they do get wiped out from the deleting preferences procedure, I have saved them? Maybe copy the file with Projects and save it on my desktop?

Thanks again.

Jeff

P.S. Per your other suggestion, the trouble clip did work fine, at least initially, when imported into a new iMovie Project.

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