iMovie pixelated video for a few seconds at or after transitions (Cross Dissolve).

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Level 1

4 points

iMovie pixelated video for a few seconds at or after transitions (Cross Dissolve).

Problem with iMovie, pixelated video for a few seconds, mostly at or after transitions (Cross Dissolve). Sometimes it also seems as if a “frame” from the earlier video appears immediately after the transition. Example below.

1. Looking as other forums, some similar issues suggested corrupted files, I have tried re-importing effected video.

2. As problem appears to be around the use for the Cross Dissolve, I have tried removing them and using different or no transition.

The above can solve the issue "sort of" however, the problems then appear in other parts of video. The strange thing is in preview the video can show pixelated video, then if I go back and “re-preview” this problem can disappear, but then reappear if a watch back again?

Another forum suggests resetting the defaults in iMovie then reopening library (did not help in this case)

I had my library stored on SSD external drive via USB3, tried copy paste project to new iMovie library in internal drive, but no change.

Tried importing to a trial version of Final Cut Pro – same problem.

I have opened old projects, previously unaffected with this problem, this pixelated video at cross dissolve now appears in a few parts.

Build & Versions

· iMovie 10.1.14 Build 358560

· iMac (Retina 5K, 27-inch, 2019) Memory 40 GB 2667 MHz DDR4

· macOS Catalina 10.15.2

· Video and photos taken with iPhone XS and XR.

· iMovie film c16 minutes long, audio is not affected in any way.

iMac 27", macOS 10.15

Posted on Dec 14, 2019 4:37 AM

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Answer 1

Best reply

Rich839

Level 8

47,274 points

Dec 14, 2019 8:39 AM in response to CDSnap

Hi, CDSnap,

The pixellation/artifact issue has been reported several times on this forum. Take a look at this thread:

https://discussions.apple.com/thread/250751600?page=3

There seems to be some correlation with the appearance of the pixellation and iPhone movies recorded with the HEVC format. If this is your situation you might try changing your iPhone settings to Photo/Transfer to Mac or PC/Automatic. That would give you a more compatible format. Or, you could try using the free download, Handbrake, to convert the videos to H.264, Mp4/AAC and then import the converted videos into iMovie.

-- Rich

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Answer 2

CDSnap Author

Level 1

4 points

Dec 14, 2019 1:07 PM in response to CDSnap

Appears this is the HEVC file problem from iPhone video imports, hopefully Apple will fix, as this should work (new iMac and iPhone !!!! not happy) . In meantime I have set video format on iPhone to "Most Compatible".

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Answer 3

Rich839

Level 8

47,274 points

Dec 14, 2019 3:59 PM in response to CDSnap

I have a feeling that Apple will fix this, since the HEVC format is one of the more prominent advances by Apple in its iPhone platform. However, HEVC may not be the problem. There just appears to be a correlation.

-- Rich

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Answer 4

CDSnap Author

Level 1

4 points

Dec 15, 2019 12:00 PM in response to Rich839

I agree, my older video files (mostly from iPhone 6s) work without this problem, I have switched off the HEVC on my current iPhone and will do some further tests in case the problem is something else.

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Answer 5

CDSnap Author

Level 1

4 points

Jan 21, 2020 2:34 PM in response to MiamiBourne

Not yet, I have continued editing videos in iMovie with my existing iPhone XS video files from last years holiday - some work some don't - there is no apparent pattern why. For new files, I have switched to "Most Compatible" from "High Efficiency" in iPhone camera settings - but I can't say for certain this is root cause and I have no solution for existing video files. I have just bought a GoPro and will try video from this and new iPhone XS video shot in Most Compatible and will share results - but might take me a few weeks to find time to do.

Annoyed this problem continues, spent ages trying to fix, will update with my findings shortly.

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Answer 6

Rich839

Level 8

47,274 points

Dec 14, 2019 8:46 AM in response to Rich839

Three days ago there was an update to iMovie 14.1.14. If you haven't already, you might try updating iMovie and see if that helps with the pixellation issue.

-- Rich

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