Here's the use case.
I have a panel discussion with 4 panelists sitting at a dais facing the audience.
I want to use a single 4k camera in the aisle to provide both an overview shot of the entire panel, and close ups of individuals through vMix cropped virtual inputs.
I will be recording/streaming in 720p.

So far, my testing with a Logitech Brio has been disappointing (perhaps there are ways of tweaking this setup).
I would like my next test to be with my 4k Sony FDR-x1000v action camera as a 4k input.
I currently use a regular Magewell hdmi>USB adapter, but that only captures 1080p.

Has anyone tried the new Magewell USB Capture HDMI Plus adapter?
Any thoughts of how well this will work? Are there better capture adapter alternatives?

Ideally, I would like to have cropping functionality similar to what Mevo is promoting, but setting up cropped multi-views of the panelists would be sufficient.

Any thoughts from folks who are doing this kind of setup are appreciated.

A PCI-e 4K capture card like those from BMD


Not as well as you expect I guess.

Your vMix project is set for UHD so that you can input your UHD source, although you stream at 720p
Then when you use the cropped portion of the image it is upscaled by at least factor 3 > this will be very blurry
At the end everything is downscaled to 720p but the blurry will remain

I have not tested this myself (no 4K capture device either) but as far as I understand how vMix works, you won't be able to input a 4K source unless your project is set to 4K.

I regularly use the method you're talking about in Resolve or Premiere: it works because we can import UHD footage in a 1080p or 720p project, so there is absolutely no loss when use the zoom factor. But I don't think it's the same with vMix.

Let us know, I'm interested to get your feedback if you experiment this.

Guillaume

I am running vMix 4k edition, on a laptop computer.

The computer I tested on was an MSI with an i7 6700 quad core processor and an Nvidia 960 onboard graphics.
Tomorrow, I will be switching that out to an Asus with an i7 7700 quad core with Nvidia 1050 graphics onboard.

I just did a test with a Brio on a desktop computer...

I changed the project to 2160p instead of my previous 720p
Then I set the recording and external devices to 720p

I then used vMix's zoom shortcuts to magnify the Brio's image... it worked MUCH better than when the project was set to 720P...

I will do more testing tomorrow, but the results are encouraging. The Brio still lags behind a C920 by a very little bit...

The key here may very well be to match the project properties to that of the highest resolution camera, regardless of the intended outputs.

The use of 4:2:0 sampling is a pity. Down-sampling 4:4:4 to 4:2:0 is a terrible waste.

It would be nice if there was silicon to support some simple compression scheme, like that used in NDI. That would allow them to retain 4:2:2 sampling over the USB 3.0 link. Generally better for production purposes.

When I switched over to vmix it took some testing to figure out, but I use the BMD 4K pci declink mini recorder with a 4K gopro5 for situations when we have no room for production cameras, large tripods or need to do a single operator stream in a very small/tight location. I usually setup 4 or 5 virtual inputs with different zoom and pan points. Also often use an ipad with OSCtouch to control preview pan and zoom via midi.
So far I have found 4K UHD input into a 1080 project streamed at 720p works best for my setup. With pretty crisp video, you do need pro or 4K version of vmix to bring in the source at 4K.

Next time I do a single 4K camera setup I will try to get a video of my setup/settings and share on the forums.

This is a feature I used in Wirecast 7 all the time on our Macs, so I am glad I got it working in vMix.

-SHMD