Stuttering of video files in mimoLive 6.3.1 on M2 Max

as posted by someone else on Facebook, I’m also reporting here the problem.

I’m experiencing random stuttering of ProRes LT and H.264 files on Mimo 6.3.1 on a M2 Max 2023 Macbook Pro.

I’m running tests ongoing for hours with looping videos. It never happened before and it’s a real issue for me.

I’ve been using mimolive since 2020. it was my understanding that Prores files are “lighter” on the CPU/GPU because they don’t need to be transcoded as H264 files.
So I always used Prores motion graphics and videos and never had any problem, leaving ample headroom to the GPU and CPU for everything else.
I recently switched to an M2 Max Macbook Pro and I’m having this stuttering which seems counterintuitive with Prores.

Anyway, I’m having problems with H264 files as well – not only ProRes. The stuttering is random, but definitely there.

I’m just using a normal Blackmagic output, but the stuttering is definitely present in mimo even before being output to the BM card.
I’m not using any NDI or similar aux outputs.

Any help from the developers?

Hi @fermento This is very concerning and we’re looking into it. Right now the challenge is to reproduce it. Could you please provide us with a sample document and the files that exhibits this problem? You can DM me a link to Dropbox or similar here in the forum. Thank you for your support.

Do you experience the stuttering also when you play the files with the Quicktime Player?

Are the files stored on the internal SSD drive or on an external drive?

great to read your responsive comment Oliver!

I’ll send you some material.
The stuttering is not present in quicktime.
I’m playing all the source from the internal SSD drive.

I’m testing my old intel mbp with mimoLive 5.11 (my workhorse!) on Big Sur.
Not a single frame glitching, same project, same blackmagic ultrastudio on output.

FYI, I’m the “someone else on Facebook”. My scenario is basically identical to that of @fermento including the fact that the same files play back fine on Quicktime player. My workaround during last month’s live stream (concocted while on-air) was to play back the files on QT player using a window capture source. Playback was fine this way, but I’d like this to work the way it should via mimoLive.

If it’s of any use to know, @Oliver_Boinx and @fermento, the ProRes files are stored on the internal SSD drive, but I use the “Absolute Path” option instead of “Copied into document”. I don’t know if that makes any difference but I thought I’d mention it.


same here, I’m using the internal ssd, and always have used the “absolute path” (mainly because I’m constantly swapping the projects between a prep and a production Mac – but mostly, because it just feels right and easier to replace files).

To add something to this: the random stuttering is not so huge in terms of stuttering variations, at least here. It’s like skipping frames or something similar. It may go unnoticed in a fast paced video or to a casual viewer. I’m mostly using slow- to medium-paced animations looping in my productions, so it’s definitely noticeable.

Hi @undercrank, hi @fermento Thank you for reporting your findings and bringing this to our attention,

Your bug report has lead us to a major issue that really impacted performance, especially on Apple Silicon. We’ve taken the first steps in mitigating this issue and have been able to vastly improve mimoLive performance. Can you please check the latest beta to see if you also see those improvements:

@Oliver_Boinx - thank you, and to @Achim_Boinx and the rest of the team for digging in to the code and working on this. I will download the beta and run it with my show docs & mov’s (which I’d sent to Achim) in the next couple of days.

Hi @undercrank @fermento

This should now finally be fixed in mimoLive 6.4b8:

Can you please download and check and report back to me?

@Oliver_Boinx sure! Thanks to you and the team for working on this issue.


@Oliver_Boinx and @fermento - this morning I finally had some time to do a preliminary test of this latest beta. I was able to open up my two show documents, one of which holds three ProRes files about 3-5GB each and which is connected to the other via a syphon layer. I then connected 2 mimoCalls, as I’ve done for all our livestreams.

I found that the video playback was not affected, and the area of the M2 MBP above the keys that usually heats up did not get hot (or even warm). I kept this open for about 10 minutes and there was no change. Yay!

I would like to test this again when I have time to leave everything open and connected for about an hour to see if I can “break” the new beta before throwing confetti in the air, but this is very promising.

I am curious to hear of any results from anyone else who’s road-tested this beta.

Thanks again to Oliver, @Achim_Boinx and the rest of the team for digging in to the code to help resolve and fix this bug.


Hi @undercrank Can you please check once more with mimoLive 6.4?

Sure! I’m away until Thursday, but will crank up 6.4b8 at the end of the week and report back on how many video files and mimoCalls I can add and what the results are. Sorry it’s taking me a while to focus on this. I really appreciate the work you and the team have done and are doing to make mimoLive work with the new M2 Macs.


Please use 6.4 final!

Okay. I didn’t realize that the linked 6.4 (above) was a final and also another iteration past the 6.4b8 beta. I will download the final and test that one out next.



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@Oliver_Boinx I’ve just had a chance tonight to thoroughly test the 6.4 Final edition, and everything worked just right. We set up all the connections, files, mimoLive documents, mimoCalls and ProRes files just like it was one of our shows and ran it all for about half an hour. The bottom of my MBP - which sits on a coolpad with 5 fans in it - never even got warm. Video files played back fine, and no need for an ice pack.

Thanks again, Oliver, @Achim_Boinx and the rest of the team for going under the hood and digging in on the code. I will let you know if anything else comes up.


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@Oliver_Boinx, @Achim_Boinx and the rest of the mimoLive team,

We had a successful live-stream today, 90 minutes plus ½ hour before going live, no problems at all with ProRes playback. Didn’t even need an icepack.

Thanks again for helping solve this big issue with 6.4!


@undercrank Ben, Thank you very much for your feedback! Glad to hear that everything worked out for you!