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problems with iMovie 10.3

I have macOS Big Sur version 11.6.

Last Sunday I used it and it worked flawlessly. I import a large video (5GB), perform edits, and export the result - which takes about a half hour.

iMovie was recently updated to version 10.3 and it seems I was auto updated.

This Sunday it's terrible.

With the imported file, the video part seems fine, but the audio part seems to take forever to appear. I'm talking hours here.

The export, likewise, is taking forever. The process status circle says it's going to be 5 hours for a 1 hour output video.


Has anyone else had problems with iMovie 10.3 ?

MacBook Pro 15″, macOS 11.4

Posted on Oct 24, 2021 5:06 PM

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Question marked as Top-ranking reply

Posted on Nov 1, 2021 6:32 PM

Thanks for all that great data.


You are correct that not all Mp4 files work in iMovie. It must be Mp4/AAC. AAC stands for Advanced Audio Coding.


If you have time and can do a little more experimenting per below, and post back with your findings, it may help us to track down the problem.


Your original clip has the letters HE in the codec. That might be short for HEVC, High Efficiency Video Codec. The exported clip does not contain the letters HE. Perhaps HE, if it means HEVC, is what is causing the problem. Put your original clip into QuickTimePlayer and do a Window/Show Movie Inspector. Does it show the format as HEVC? If it were recorded in HEVC, you can export it out from your iPhone and eliminate the HEVC by going to Settings>Photos>Transfer to Mac or PC and disabling "Keep Originals". Then export the clip. If you try that, see if the exported clip will work in iMovie.


Another thing you can do is try converting the troublesome clip to H.264, Mp4/AAC with the free download, Handbrake. 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. Then see if the converted clip exports normally in iMovie.


Another experiment that you might try is to import your original clip into iMovie and do a Modify/Detach Audio. Then delete the audio and export out only the video. If the video-only exports quickly that would indicate that the problem is with the audio codec.


-- Rich





12 replies
Question marked as Top-ranking reply

Nov 1, 2021 6:32 PM in response to davec1066

Thanks for all that great data.


You are correct that not all Mp4 files work in iMovie. It must be Mp4/AAC. AAC stands for Advanced Audio Coding.


If you have time and can do a little more experimenting per below, and post back with your findings, it may help us to track down the problem.


Your original clip has the letters HE in the codec. That might be short for HEVC, High Efficiency Video Codec. The exported clip does not contain the letters HE. Perhaps HE, if it means HEVC, is what is causing the problem. Put your original clip into QuickTimePlayer and do a Window/Show Movie Inspector. Does it show the format as HEVC? If it were recorded in HEVC, you can export it out from your iPhone and eliminate the HEVC by going to Settings>Photos>Transfer to Mac or PC and disabling "Keep Originals". Then export the clip. If you try that, see if the exported clip will work in iMovie.


Another thing you can do is try converting the troublesome clip to H.264, Mp4/AAC with the free download, Handbrake. 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. Then see if the converted clip exports normally in iMovie.


Another experiment that you might try is to import your original clip into iMovie and do a Modify/Detach Audio. Then delete the audio and export out only the video. If the video-only exports quickly that would indicate that the problem is with the audio codec.


-- Rich





Oct 25, 2021 8:10 AM in response to davec1066

If by chance you are exporting at Best Quality (pro res) that can slow down export time by 4x. Pro res is a very high bitrate setting and is not needed unless one is going to do very technical professional editing.


Lack of application space for iMovie to run efficiently can also cause slow exporting.


Then, possibly, your system just needs a little tweaking after the updates. Try these two procedures, that are easy to do and and simply involve rebooting while holding down certain keys:


Try resetting the System Management Controller (but no longer available for the new M1 computers):


https://support.apple.com/en-us/HT201295


Resetting the NVRAM or PRAM


Try resetting the NVRAM or PRAM:


https://support.apple.com/en-us/HT204063


The above may cure the delay in sound, although I'm not quite sure what you mean when you say that the "audio takes forever to appear". Sometimes Mp3 audio can cause some problems, so if you are using Mp3 you might consider changing the audio codec to AAC or AIFF.


-- Rich


-- Rich

Nov 3, 2021 8:50 AM in response to davec1066

Looks like we reached the same place by different routes. Converting the clip seems to be the workaround. I agree completely that no one should have to do a workaround to make iMovie work. Hopefully Apple will fix the problem.


You can give feedback directly to Apple at this link:


https://www.apple.com/feedback/imovie.html


I am still curious as to whether the original clip was in HEVC format. No sure what the "HE" means. Could you by any chance open the original clip in QuickTimePlayer and do a Windows/Show Movie Inspector? That would reveal whether the clip is in HEVC format.


Thanks, and glad that you found a workaround.


-- Rich

Nov 1, 2021 4:41 PM in response to a_lef_iv

I'm the one who filed the first problem statement. I'm glad to see that I'm not the only one with the problem, but sorry either of us has it.

Another Sunday, and I had a new '.mp4' file to work on. Again, it had video but no sound. I found that by playing a section over and over, it would eventually add the audio, but expect to have to wait frequently for the spinning 'busy' circle. the photo shows a section that has audio shown followed by a no-audio section.



When I got all the audio filled in and made my other edits, I proceeded to export the result. The result was another '.mp4' file. For a video with a running time of an hour and a quarter, it took 8 hours and 46 minutes to export, as the following image taken from 'Get Info'.



Now, here's the real kicker. If I make a new movie by importing the file just produced with so much trouble, (1) the audio is loaded together with the video, (2) exporting it only takes 6 minutes and (3) the resulting file is 7% smaller.


My major take on this is that iMovie has a problem with some .mp4 files and not with others. So what is it that would make some files different from others? Here is the 'Get Info' for the original video with the problem on the left and its resulting output file on the left. Is the something special about AAC ?


Nov 2, 2021 5:54 AM in response to Rich839

Thanks Rich,

I'm sure this works, but I did it differently -- before I read you solution.

I woke up in the middle of the night convinced that AAC was the problem. So I used Total Video Converter Lite (which I already had). Using the circled menu I selected Video ➞ MP4 (H264). The APP didn't change the file name, so I changed the destination to a different folder.



The APP quickly created the new file. The following shows the before and after characteristics:



loading this into iMovie showed audio, although it took a second or two to appear. I then added the title shown along with beginning title and end credits:



I exported this project. It took less than 10 minutes. This final picture shows the end characteristics:



So there are now two work-arounds that solve the problem. However, I believe the fault is in iMovie. We should not have to do a work-around -- I didn't have to on October 17th and earlier. I believe it was broken on October 18th with the release of version 10.3.

This needs to be fixed in iMovie!!! how do I report this to the developers?


Dave Clarke

Nov 3, 2021 1:50 PM in response to Rich839

Rich,


Here's a screen shot of the Quicktime Movie Inspector. I'm afraid it just continues to call it MPEG-4 HE AAC.

I found information about it at https://en.wikipedia.org/wiki/High-Efficiency_Advanced_Audio_Coding. It appears to be an audio coding whereas HEVC is a video encoding (https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding). But what do I Know? I retired from the rapidly changing IT industry 9 years ago, but it looks like I can still debug some software problems 🤣.


Dave



Oct 24, 2021 7:53 PM in response to davec1066

I'm not running iMovie 10.3, so can't comment there.


Sometimes with an update preferences get corrupted or changed. Try deleting 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.


-- Rich

Nov 3, 2021 2:43 PM in response to davec1066

Ah. So, HE AAC is intended for streaming whereas AAC is for higher quality. Apparently HE has a different algorithm. As I mentioned before, iMovie likes Mp4/AAC. Possibly the algorithm for HE AAC might not be compatible with iMovie, and that might what caused the problem. When you re-encoded, the HE was eliminated and you were able to export at normal duration. Just my speculation, of course.


Thanks for taking the trouble to post the data.


-- Rich

Dec 25, 2021 2:57 PM in response to davec1066

I have similar problem. It updated, saying optimisations for Apple Silicon. I thought it would work faster than before. But the render/export times have got worse. I used to make short family videos, 10-15 mins longs. And it would take 5 mins to render in 4K. Now it says oner 3 hours. What went wrong? The videos were shot on iPhone so I trust its nothing to do with incorrect codec or something similar. Apple should understand those files very well.

problems with iMovie 10.3

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