Artifacts in iMovie

As a longshot, you might look at System Preferences/Accessibility/Display and see if either or both of the boxes "Increase Contrast" and "Reduce Transparency" are checked. If they are, uncheck them and see if that helps. If no luck you can always re-check the boxes if you want.

-- Rich

I'm having exactly the same issue with the very same setup on Catalina, this is utterly annoying. Without transactions working the tool is pretty much useless for creating content. Hope they fix this asap.

I'm also getting artefacts introduced when rendering. iOS 13.1.3, videos all shot on iPhone XS, MacBook Pro 2019, macOS 10.15.1, iMovie 10.1.13.

The affect several files in a project and none of the suggestions offered have worked. I've only used the fade to black transition at the end, but most of the files are clipped. I get blocky compression artefacts and ghost images of other files in the project. The original files are fine when played and also when rendered as the sole file in a new project.

I've provided feedback via the link posted above, so hopefully it will get fixed.

Thanks for all the suggestions.

I'm having the same issues. I'm guessing the artifacts are the same as what I am seeing. My footage was shot on an iPhone XS and I was first seeing the issue in iMovie. I've been thinking about upgrading to Final Cut Pro, so I made the leap thinking that maybe that would help..... same problems. I just edited another movie shot on someone's older iPhone (not sure which one maybe SE) and there are no issues at all. I can't nail down what is causing the issue. With Final Cut I can export it in a number of ways.... though the artifacts seem to happen in different places each time for me, they are still there.

I have similar problem, iMovie, MacBook Pro (2017), Catalina, movies recorded with iPhone 7 and GoPro. Artifacts are every couple of seconds of the output movie. I already experience similar problems on Mojave, but artefacts were much less frequent. Currently the output is unacceptable due to the artefacts...

I'm only doing small parts now to test, but I swapped out one of the clips that was being affected and it did fix that one, but then it happened in another place which was fine before.

In my projects this is not directly tied to transitions, since I do not have many of them.

Actually, I meant to say "iPhone videos". Sorry. The artifacts could happen with photos as well, however. The posts I have seen refer to videos.

You might try taking out the photo and see if that resolves it. What format are the iPhone videos shot in? If it's HEVC perhaps that is the issue.

Also, you can do some troubleshooting.

Boot up in Safe Mode (see Finder help menu for instructions) and, after everything loads, immediately shut down and reboot in normal mode.

Create a new project with your media and see if it works O.K. there. Also, try with non-iPhone videos and see if the artifacts are gone.

Open iMovie while holding down the Option and Command keys and selecting 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. Now see if the artifacts are gone.

Open iMovie in a new library, copy your project there, and see if you can share out without artifacts. You can open in a new library by opening iMovie while holding down just the option key and selecting to create a new library in the box that appears.

Nothing that has been tried on this seems to have worked for other posters. It might be something that Apple needs to address.

-- Rich

-- Rich

Thx again Rich for the workarounds, I tried all of them before, but nothing helped 😕

My videos are all HEVC Full HD 60p taken on an iPhone XS. All projects containing those videos have issues, older iMovie projects with H264 videos from my older iPhone seem to be OK. Is it the same with you guys experiencing the same problems?

However, it's a pretty bad defect that came with the Catalina update and that needs to be fixed urgently...

Thanks for posting back. So, your HEVC clips are the ones with the issue.

Try exporting from iPhone with the Automatic setting to get a more compatible format. Either that or try converting the already exported HEVC clips to H.264, Mp4/AAC, that Handbrake will do by default. Then import the converted clips into iMovie. See if either of the above works.

— Rich

— Rich

For the record I'm not on Catalina yet, so I don't think that the OS is the problem.

I've been working on Rich's suggestion and converted my clips to mp4 using handbrake. I've started piecing my movie back together and so far everything is looking really good. I'm willing to say that this is the solution until Apple gets it sorted out.

It's frustrating that this doesn't work out of the box using standard Apple products front to back.... This gear is too expensive not to work. Figure it out, Apple...

Same thing happens to me. No Photos in the project, no HEVC files and not on Catalina. However on iMovie 10.1.13 and did not have this issue on 12. I have tried all the solutions regarding new projects, deleting preferences etc. No luck.

I don't know of any way of reverting back to previous iMovie version without Time Machine, unless you have a non-Time Machine backup drive that contains the earlier version. Possibly you can find a website that can provide a download, or perhaps you have a backup older computer that you can copy it from.

-- Rich

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Also so disappointed that the new release doesn't help. I even tried re-importing and creating new projects and all the other fixes suggested before in the new version in the hope that it would resolve. Then I finally just got my hands on a copy of 10.1.11, but if I try to open my projects or library in this version it terminates with at the error that one or more of the libraries were created with a newer version of iMovie. Seems I am completely at the mercy of Apple.