Those of us moving to streaming or recording video are always looking for a good switching unit. While at NAB 2015, I checked with Roland and their VR-50HD and VR-3X mixers.
The VR-3EX is a four-channel SD video mixer. This mixer will send a 480i signal through the USB 2.0 port, or upscaled 1080p through HDMI. The 3EX includes 4-HDMI input support, RGB/Component in support, HDCP support, 4 channel audio, and can be controlled through the LCD touchscreen control center.
If you need a little more power, the VR-50HD unit allows for HD streaming and recording using the USB 3.0 connection. You can also connect both HDMI (4 ports) and SDI (4 ports), and also connect RGB components (2 ports), then pass the RGB signal out to an external monitor. 3 HDMI out allows to connect to a monitor, another streaming device and more.
The VR-50HD also has up to 12 channels of audio - perfect for connecting microphones, break music, computer audio and more. A MIDI feature and RS-232C connector for a remote is also available.
Clearly, the VR-50HD is the more powerful work horse, but if you are simply switching between four cameras, the Roland VR-3EX can be what you need for the job you are doing.
Both of these devices do not record from the unit, so you will need an external recorder - either through computer or other unit. The computer sees the USB connection as a USB camera, therefore, you will be able to send to a streaming service like uStream, Livestream, Google Hangouts and more without issue.
The Roland VR-3EX is $2,195 and the VR-50HD is $7,495. For more information, check out the Roland website (http://proav.roland.com/products/productlist/480)