Hardware problems since upgrading

First, this is used in a small K-8 school in Maine for making monthly newscasts in 2nd grade and other class projects. We are looking at simple and low-buck systems here.

I have a Mac Mini (16GB Ram, 512SSD) that we used as our video controller. We used to run BoinxTV and either a USB Webcam or a Canon Vixia HF R800 camera connected to a Black Magic Design UltraStudio HDMI to Thunderbolt 2 adapter.

We just upgraded the system to MimoLive this year and things are not working right. Using the Black Magic device we are getting poor quality and MANY dropped frames. It looks like a slow strobe effect.

Does anyone have a good solution for us? I looked at getting a better mac, but not sure if I can/should put $2K+ into a new machine that doesn’t get a lot of use and still may not work (iMac). I also thought that some type of hardware encoder might work and take the strain off the computer.

Best case scenario would be us using both the webcam and the Canon that we can switch between.

Does anyone have any good suggestions for a fix for this? I have been trying to research external hardware encoders but I am slipping down a rabbit hole now and have little experience with the standards, etc. for video.

Thank you in advance,

Mike Brzezowski
Technology Integrator
Pemetic Elementary School

What version of MacOS are you running? Does the Mac otherwise have good performance?
Is the firmware up-to-date on the Blackmagic device?

Blackmagic’s HDMI to Thunderbolt hardware does not put a significant drain on system resources generally, so I’m wondering if the issue lies elsewhere.

I am running MacOS 10.15.3. Firmware is up to date. Mac Mini is a 2014 though and I realized it only has 8GB of RAM.

I was able to get it to stop dropping frames by saving to an external drive, but I still have major quality issues.

Here is a link to a short video to show the problem. There are no effects on the camera. Lighting is a set of softboxes with I believe 6500K fluorescent bulbs.

The video is always so grainy and poor. Any suggestions?


The video doesn’t look too bad, but it is a bit soft and grainy. The first place I would look is the camera settings.
Edit: I just noticed that you said the image on the camera itself looks fine, but the UltraStudio Mini Recorder shouldn’t be affecting the image quality. Can you get a screenshot of your UltraStudio settings in the Desktop Video software?

I am not sure, but the problem maybe have been an underpowered computer running MimoLive. I have switched to using another computer (A MacBook Pro instead of the old 2014 Mac Mini) and the quality is fine now.

Yesterday I tested MimoLive and found that the activity monitor was showing MimoLive using 220% of the CPU. I am guessing that means the CPU is maxed and there is a 120% capacity backlog???

At any rate, I am finally getting a good image.

I will have to check again, but the camera was running 1080i59.something instead of 1080p. The older Canon’s had a setting to change the output, but I can’t see a setting to change on the Canon Vixia HF R800 we are using.

WHen I get back to the studio later today I will see if it is still running at that resolution when connected to the MacBook Pro (I would guess it is).


Mike, Thanks for being a long time mimoLive/BoinxTV user!

The video you shared looks fine, the animation of the globe is smooth and I don’t see a strobe effect. What am I missing?

The 2014 Mac mini is certainly not the most powerful machine, but it should give you the same result with mimoLive that it gave you with BoinxTV. In some areas mimoLive should perform much better, in others it would be requiring slightly more resources. One thing to look out for is the resolution and encoding settings for the webcam which have different defaults for different OS versions.

Regarding the 220% CPU load: This is a bit misleading because 100% is not equal to “full CPU performance” but rather 100% of the processing capacity of a processor core. 220% means mimoLive is using a bit more than 2 cores. Your MacBook Pro has at least 4 cores, so mimoLive uses just a bit more than half the available processing power.

You might consider 720p for your environment. 1080p is probably overkill … unless there is a lot of motion or you are zooming in on race cars or blades of grass. We use 720p for all of our rare disease conference work.