iMovie Fail on M1 iMac - Same Movie Works Fine on 2019 Intel iMac

[Buadhai]

This on an M1 iMac with 16GB of RAM.

I have 32 short (about 3 to 7 minute) videos made with older versions of iMovie. I'm trying to concatenate these into one long video using iMovie 10.3.5 on the M1 iMac. I'm doing some slight editing like color correction, adding a few titles, volume correction, etc. When I get to the last few videos, iMovie freezes up with the dreaded SPOD and has to be force quit. It seems to be a problem with Core Audio. Looking at top in a terminal session shows a couple of processes that are consuming vast amounts of CPU.

Oddly, when I copy the iMovie library to an older 2019 Intel iMac (16GB RAM) it works fine.

This is ironic (?) because the old iMac is mine and the M1 is my wife's I borrowed her machine thinking that doing video would be a bit quicker on the much faster machine.

It's not. In fact it doesn't work at all.

Any ideas?

 

[Buadhai]

Update: Forgot to mention that the two out of control processes are Core Audio Reporting Service (CAreportingservice) and Core Audio.

 

[bogdanw]

Do you have Pro Video Formats installed on the Intel iMac?
/Library/Video/Professional Video Workflow Plug-Ins
Pro Video Formats 2.2.4 https://support.apple.com/kb/DL2050

 

[Buadhai]

That directory is there, but it's empty:

Sellotape:Video mnewman$ pwd
/Library/Video
Sellotape:Video mnewman$ ls -la
total 0
drwxr-xr-x   4 root  wheel   128 Feb  9 16:39 .
drwxr-xr-x  76 root  wheel  2432 Feb 14 09:01 ..
drwxr-xr-x   2 root  wheel    64 Feb  9 16:39 Plug-Ins
drwxr-xr-x   2 root  wheel    64 Feb  9 16:39 Professional Video Workflow Plug-Ins
Sellotape:Video mnewman$ ls "Professional Video Workflow Plug-Ins"
Sellotape:Video mnewman$

 

[Buadhai]

Well, this is interesting. I gave up on the M1 iMac and finished the project using the iMovie Library that I had copied to the Intel iMac.

Worked fine.

Then I copied the iMovie Library back to the M1 iMac.

Worked fine.

So, an unexplained mystery for which there will never be a solution.

Oh, well.

 

[bogdanw]

M1 was probably stuck on some rendering, Intel finished the rendering, M1 was able to export.

 

[Buadhai]

M1 was probably stuck on some rendering, Intel finished the rendering, M1 was able to export.

Possible, but I let iMovie run on the M1 overnight. In the morning the SPOD was still spinning. I force quit iMovie and copied the file to the Intel iMac and it was fine.

The M1 seemed to have trouble with the audio tracks on the last two clips. It never did display the wave form for those last two clips.

Note that I never asked iMovie on the M1 to render anything. All I did was add the clips to the project and then arrange them in order.

 

[bogdanw]

Note that I never asked iMovie on the M1 to render anything. All I did was add the clips to the project and then arrange them in order.

iMovie decides when to render. For some files, it just creates Peaks Data and Thumbnail Media. For others, it renders High Quality Media.
Open ~/Movies/iMovie Library.imovielibrary/My Movie/Render Files and watch it grow as you import files, add them to the timeline or edit them.

 

[Buadhai]

But would rendering 30 short clips freeze up iMovie for 14 hours?

 

[bogdanw]

In my experience, when iMovie freezes, it just freezes I always force quit after 10-20 seconds and try to start it again. If I can identify the clip that is causing problems, I remove it from Media or directly delete it from inside iMovie Library.imovielibrary Original Media before starting again.