Mimo Live Recordings have Video Frame Freezes

For some reason, I am getting video frame freezes (pauses) in my recordings.

Watch Here: https://youtu.be/QeAahSduXV8

This problem still occurs is despite using a high speed Thunderbolt 2 port, and a firewire 800 drive, which should be more than fast enough to produce smooth recorded frame rates.


MacBook Pro (Retina, 15-inch, Mid 2014)
Model Name: MacBook Pro
Model Identifier: MacBookPro11,3
Processor Name: Intel Core i7
Processor Speed: 2.5 GHz
Number of Processors: 1
Total Number of Cores: 4
L2 Cache (per Core): 256 KB
L3 Cache: 6 MB
Memory: 16 GB

Vendor Name: Apple Inc.
Device Name: MacBook Pro
UID: 0x0001000F050C2C30
Route String: 0
Firmware Version: 17.1
Domain UUID: 8867B535-7924-A952-A926-EDC532203D92
Status: No device connected
Link Status: 0x7
Speed: Up to 20 Gb/s x1
Current Link Width: 0x1
Receptacle: 1
Link Controller Firmware Version: 0.12.0
Status: Device connected
Link Status: 0x2
Speed: Up to 10 Gb/s x1
Current Link Width: 0x1
Receptacle: 2
Link Controller Firmware Version: 0.12.0


Vendor Name: Apple Inc.
Device Name: Thunderbolt to FireWire Adapter
Vendor ID: 0x1
Device ID: 0x8004
Device Revision: 0x1
UID: 0x0001000301175610
Apple Serial Number: DTN420701Y5F494AR
Route String: 3
Firmware Version: 5.6
Port (Upstream):
Status: Device connected
Link Status: 0x2
Speed: Up to 10 Gb/s x1
Port Micro Firmware Version: 0.0.17

MAC OSX Version:
System Version: macOS 10.13.2 (17C88)(High Sierra)
Kernel Version: Darwin 17.3.0

Version 3.1.1 (23323)

MimoLive Document Video Frame Size:
1920 X 1080
MimoLive Audio Sample Setting: 48,000
MimoLive Video Frame Rate Setting: 30

Apple ProRes 422

Audio Interface: Focusrite Scarlette 6i6 USB

@studiomike007 Sorry to hear about the troubles.

Can you please download the Blackmagic Disk Speed Test app and check the drive’s actual data rates?

I suspect it isn’t actually the drive that is causing the troubles as the sound seems to be flawless and it looks like no frame is missing, they are just duplicates. Did you notice the frame freezing also in the Program out window in mimoLive? How is the video coming into mimoLive? What camera and grabber are you using? What layer are you using to display the incoming video?

Hello Oliver! Thank You for your response. I just tested the same drive in the same configuration that I used to make the recording. The result is really bad!

The test from the external drive:

WRITE = 44.1 MB/s

READ = 43.9 MB/s

Contrasted to my Internal SSD:

WRITE = 637.3 MB/s

READ = 703.7

I was expecting to see around 200 MB/s for the external. So I assume my results are the problem?

You asked: “Did you notice the frame freezing also in the Program out window in mimoLive?”

Yes, I did. Also a yellow indicator would flash next to the “start/stop” button in the interface. You said that you feel that frames are being duplicated? I found that interesting because MimoLive did not report dropped frames.

You asked: "How is the video coming into mimoLive?

Video is coming in from a Sony HD Handicam via a HDMI Cable.

You asked: “What camera and grabber are you using?”
The video grabber is a Blackmagic Ultra Studio Mini Recorder.

You asked: “What layer are you using to display the incoming video?”
I am using the standard Placer to display the video.

If the drive is a issue, would you mind providing me a suggestion of a drive to use that will perform better?

Thank You!

@studiomike007 Thanks for checking your drive. It seems as if this is the most likely candidate for the problem after all. Although 44.1 MB/s should theoretically be enough as 1080p30 ProRes 422 uses about 27 MB/s, the OS is periodically updating the directory information on the disk which might explain the dropouts.

I’d recommend to get a modern 3 TB USB 3 drive. We had great experiences with those, even with the pocket sized ones. Of course, a USB 3 SSD will be even better, but also much more expensive.

Thank You Oliver. To be honest, I shocked at the poor performance results. The Drive I used is a Lacie Rugged. It is equipped with FW 800. The fact that it didn’t even get me 50 MB/s really seems strange. I updated my MBP to High Sierra, and I formatted the Lacie drive with Disk utility.

You mentioned that OSX periodically updates the directory on the disk. Is there a way to avoid that during recording/Streaming? I can understand OSX doing that to the boot drive, but why would it need to do that to an external?

I also just tested two western digital USB 3.0 drives. a 4TB and a 3TB drive. Given my macbook pro’s specifications, the USB ports are rated up to 5GB/s per sec rating. Yet, when I test these two drives, the best it’s giving me is about 125 MB/s. I’m not sure why I’m getting such slow transfer speeds.

Is there anything else I can check to see what might be making my system busy that might be affecting my transfer speeds?

Thanks Again!

@studiomike007 125MB/s seems quite fast for a hard drive. Using spinning magnetic disks and a mechanical read/write head is by default slow. The way to get around that is using RAID systems or SSDs. The USB 3 port is not the bottleneck in this case.

If you write data to a disk, the meta information about where the data is stored and how much of it there is and so on needs to be updated periodically to avoid data loss. Using SSDs this is ultra quick, on a disk drive the read/write head might need to move significantly to get to the space on the disk where that data is stored.

Also any background process (such as a virus scanner or email downloads and so on) can cause the OS to writing or reading data from the disk while you are recording. It is best to have a clean system with only mimoLive and the necessary components installed.

Yeh, 125MB/s is actually really fast for an external drive and should be more than enough to write at the data rates your require.