iMovie Performance on M1 & M2

[pacmania1982]

Hi guys:

I have an 2020 MacBook Air M1 base with 16GB RAM and a 2023 Mac mini M2 with 16GB RAM. When exporting a quick video in iMovie, the CPUs are hardly taxed leading to long export times.

I don't want to invest in Final Cut Pro or learn how to use Da Vinci - I only want to crop drone footage or GoPro footage and export to upload to YouTube to share with family and friends.

Here's a 5 minute drone video exporting after I'd cut out some bits that were a bit rough. No colour correction or anything - but the CPU cores were hardly used (efficiency) and near zero on the performance cores.

Is there anything I can do to help?

 

[avkills]

Hi guys:

I have an 2020 MacBook Air M1 base with 16GB RAM and a 2023 Mac mini M2 with 16GB RAM. When exporting a quick video in iMovie, the CPUs are hardly taxed leading to long export times.

I don't want to invest in Final Cut Pro or learn how to use Da Vinci - I only want to crop drone footage or GoPro footage and export to upload to YouTube to share with family and friends.

Here's a 5 minute drone video exporting after I'd cut out some bits that were a bit rough. No colour correction or anything - but the CPU cores were hardly used (efficiency) and near zero on the performance cores.

Is there anything I can do to help?

View attachment 2209329

I am not sure what iMovie does in the background; but I would suspect it does not utilize resources as good as FCP or Resolve; but you may be able to get the same encoding chops by purchasing Compressor. Although I have no idea how you would export from iMovie to Compressor, since I do not use iMovie ever.

 

[OhSEx]

iMovie is literally the exact same nle as fcp under the hood. Yes genuinely. They just change the UI.

I would guess if it’s taking very long then either something is off (obviously!) or perhaps the GoPro is using a nonstandard codec which macOS doesn’t have acceleration for. In any case, using fcp wouldn’t help.

 

[avkills]

iMovie is literally the exact same nle as fcp under the hood. Yes genuinely. They just change the UI.

I would guess if it’s taking very long then either something is off (obviously!) or perhaps the GoPro is using a nonstandard codec which macOS doesn’t have acceleration for. In any case, using fcp wouldn’t help.

That figures. I don't use any of Apple's Pro software anymore. Burned too many times to trust them.

 

[OhSEx]

That figures. I don't use any of Apple's Pro software anymore. Burned too many times to trust them.

I much prefer fcp to any other nle. I use Logic but don’t know enough about the other daws to compare.

 

[pacmania1982]

Here's a screenshot of the video codec information from QuickTime Player. This is just footage of my DJI Mini 2.

 

[OhSEx]

Here's a screenshot of the video codec information from QuickTime Player. This is just footage of my DJI Mini 2.

That doesnt tell us much unfortunately. Probably better to look at some of the DJ forums to see if there are any similar reports. I had a quick look and it seems like it might be quite common, but as I said, I dont have the time now so could only look quickly.

 

[pacmania1982]

Do you have any URLs I could go read up? If I need to change the codec I'm using I'd be happy to do that. I did try Da Vinci resolve yesterday to see if that would light up the performance cores and it was negligable.

In the grand scheme of things, I'm not terribly worried about it as it's not what the Mini was purchased for, I was just a little disappointed with the performance.

 

[galad]

The CPU is not used because it's not needed, both decoding of the original video and encoding is done on dedicated hardware, scaling and effects are mainly done on the GPU.

You said the video is 5 minutes long, but you didn't say how long it took to export it.

 

[pacmania1982]

The CPU is not used because it's not needed, both decoding of the original video and encoding is done on dedicated hardware, scaling and effects are mainly done on the GPU.

You said the video is 5 minutes long, but you didn't say how long it took to export it.

See this is why I think I'm missing something. I hadn't thought that lets say, the media engine on the CPU is doing all the heavy lifting and therefore it's performance isn't being registered like general CPU performance is measured. So you might be right.

The video took about 4 minutes to export. All I did was chop out some small parts that I didn't want in the video and put some music on so it wasn't just 5 minutes of boring drone footage.

 

[galad]

That doesn't sound too slow then. I guess you are exporting to a 4k resolution at 60 FPS.
iMovie has got to reencode everything, so that takes a bit of time. There are apps to losslessly cut video, and those are fasters because they don't need to reencode. But encoding 4k at 60 FPS will always take time.

 

[MajorFubar]

This has got to be partly due to the codecs the original video uses. I use iMovie quite a lot. I use an M1 Max Studio. It will export 5 minutes of 4K footage shot on my phone, colour corrected with edits and effects, quicker than it's taken me to type this reply. However I shoot at 25fps, so that makes a huge difference.

 

[pshufd]

Hi guys:

I have an 2020 MacBook Air M1 base with 16GB RAM and a 2023 Mac mini M2 with 16GB RAM. When exporting a quick video in iMovie, the CPUs are hardly taxed leading to long export times.

I don't want to invest in Final Cut Pro or learn how to use Da Vinci - I only want to crop drone footage or GoPro footage and export to upload to YouTube to share with family and friends.

Here's a 5 minute drone video exporting after I'd cut out some bits that were a bit rough. No colour correction or anything - but the CPU cores were hardly used (efficiency) and near zero on the performance cores.

Is there anything I can do to help?

View attachment 2209329

What would you consider long export times?

I do 4k videos to YouTube as well using iMovie and it doesn't come close to using up all CPU resources. I wouldn't expect it to as it's doing a lot of compression and it's often difficult to do that with highly parallel code. I'd point you to the source code for Huffman encode and Zig-Zag processing as examples. These are used in jpeg but should be illustrative.

 

[pacmania1982]

I'm not really an expert and this area is new to me. I know it's not a fair (and excuse the pun) apples to apples comparison, but when I do an export on a PC using Premiere say - the CPU maxes out, the fans go mad etc. So I'd have expected the CPU usage of any of the processes on the Mac side of things to use a lot more than they do. But that's may be because I don't understand really what the whole process is and like I said previously, it might be that another part of the CPU is doing the heavy lifting and that percentage isn't the best to look at for this type of workload. I was just interested.

What I'm hoping is to gain an understanding that actually my M1 and M2 machines are super busy doing their thing, the CPU counter is a bad metric of how busy the machines are and for best performance I should use this codec at this frame rate.

I just feel that things have moved on so quickly, I'm just stabbing around in the dark.

 

[mcnallym]

Can see the VTEncoderXPCService and VTDecoderXPCSerivice in use which is communicating to VideoToolBox which will then use the MediaEngine dedicated hardware to do encode and decode process rather then CPU.

so would not expect the CPU cores to be busy with this task and seeing those process in use confirms is going off with Videotoolbox and not just CPU cores.

why taking so long though don’t know. Possibly the mini only has one media engine whereas the Max has 2 so could encode one and decode other.

 

[pshufd]

Can see the VTEncoderXPCService and VTDecoderXPCSerivice in use which is communicating to VideoToolBox which will then use the MediaEngine dedicated hardware to do encode and decode process rather then CPU.

so would not expect the CPU cores to be busy with this task and seeing those process in use confirms is going off with Videotoolbox and not just CPU cores.

why taking so long though don’t know. Possibly the mini only has one media engine whereas the Max has 2 so could encode one and decode other.

I usually see ProRes processes when it's using those.

Code to do compression is often branchy as the code has to take paths depending on the incoming data. There is code that can run in parallel for something like discrete cosine transform but some of it can be bound by memory access time which is really slow compared to CPU speeds.

It would be interesting to see what could be done to speed up those processing parts.

 

[avkills]

Well on the Premiere side of things, nice beefy GPUs are what will speed up encoding time. 4k does take time though for sure. On my Mac Pro with a W6800X Duo, I can crank out 1080p30 fps things that are an hour long in about 6-8 minutes. Simple math would say a 4k one would take 4x longer but it would probably be closer to 5x longer.