How a video mixer works

This switching is usually achieved using predefined video transitions, which helps to make the switching from one source to another more visually pleasing and less jarring to the viewer. Some switches also allow multiple feeds to be blended together using a picture-in-picture approach, e.g. with one video provided as a smaller overlay on top of a current main video. Video mixers also often provide a way to add logos, lower thirds, and other text as overlay on the final video.

Dedicated hardware mixers

Dedicated hardware video mixers have all the above functions built-in and further come with a physical T-bar for selecting and transitioning from one video source to another. Some dedicated mixers also include an Ethernet connection that allows the mixer to connect to the internet and thus livestream directly from the mixer. If your dedicated mixer does not support direct streaming, you have two options: send the output to a dedicated physical encoder device, or send the mixed video to a computer which has software for encoding and sending. Most dedicated mixers also have a Multiview output which can be connected to a monitor to view all the video sources simultaneously. Examples include the Blackmagic ATEM series, Roland Video switchers, and YoloLiv YoloBox Pro.

Computer-based mixing

If you do not have a dedicated mixer, you can also use a standard computer as a video mixer. However, your computer needs to be powerful enough to support the video mixing and encoding process, which is quite CPU-intensive. Since conventional computers do not have any means for receiving video from HDMI/SDI sources, you need HDMI capture cards, which accept video from your HDMI cable and convert this to USB. You will need as many HDMI-USB capture cards as the number of video sources that you wish to mix. You also need to install software for performing the actual mixing and encoding. Examples of such software include vMix, WireCast, OBS Studio, XSplit, and Streamlabs. The mixing/encoding software usually provides means for adjusting video colors (gamma, contrast, saturation, intensity, etc.) and is also used to send the mixed and encoded video to online platforms such as YouTube and Facebook.