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Akheem  
#1 Posted : Saturday, July 13, 2019 4:09:02 PM(UTC)
Akheem

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Joined: 7/13/2019(UTC)
Posts: 1
Canada
Location: Mississauga

Hello,

I am in the testing stages right now.
Here's my setup:

2X canon HF R800 Camcorder
2X Camlink 4K USB Capture
Processor: Intel Xeon E5-2630 V2@ 2.60 GHz
32 GB DDR3 EC Ram
Nvidia Quadro K2200 - 4GB GDDR5
300GB SAS Driver 15000 RPM
500GB WD 7200 RPM
3TB USB3 WD 7200RPM
USB3 Bus all through

When I add the cameras to vmix. First camera works great. Silky smooth video @ 1920x1080 59.94p. 2nd camera however always suffers from jerky video. Resolution on the cameras is the exact same. connections are fine. Video Format is YUY2.
Someone help asap. I have a big project coming up in a week and want to get this running smoothly.

Thanks
AJ
ask  
#2 Posted : Saturday, July 13, 2019 4:50:49 PM(UTC)
ask

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My guess is that you are overloading the USB bus. Put the camlinks on separate ones.
thanks 1 user thanked ask for this useful post.
mjgraves on 7/14/2019(UTC)
Barney Box Lane  
#3 Posted : Monday, July 15, 2019 7:03:59 PM(UTC)
Barney Box Lane

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camlinks on the usb with the blue bit inside so it's powered or fast maybe? I haven't had fully smooth footage through an elgato yet to the point is have it as a main camera but there's so many things you can't really go off that unless loads of people are experiencing that
mjgraves  
#4 Posted : Tuesday, July 16, 2019 3:36:04 AM(UTC)
mjgraves

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Camlink does not do any frame rate conversion or scaling. Nor does it compress the video over the USB link. It only delivers YUY2 uncompressed.

A single 1080p60 stream of YUY2 uncompressed requires 3 Gbps.

A USB 3.0 bus theoretically delivers 5 Gbps. In practice, it delivers something substantially less. Think 4 Gbps.

So you cannot use two Camlinks, with 1080p60 sources, on one USB 3.0 bus. If you try this you'll find that only one works.

To deliver 4k30, the device uses NV12 encoding. It's still uncompressed, but the 4:1:0 color sampling reduces the bandwidth required just enough to fit across a USB 3.0 link. The Logitech Brio 4K webcam uses NV12 as well.
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