HDMI

Standard (passive) HDMI cables support video up to 8K resolution, which is much more than the typical Full HD livestream. Regarding distance, HDMI cables are generally usable up to about 15 meters for 1080p signals. Active HDMI cables have an internal signal booster and could be usable up to 30 meters for 1080p signals. HDMI extenders based on Ethernet cable can send HDMI signals up to 250m. Extenders based on optical fiber can send HDMI signals up to 300m. If you wish to use these extenders, check that the latency of the specific model is very low (anything with latency less than 0.1 second should be OK).

Serial Digital Interface (SDI)

SDI is the preferred video cabling for professional video, e.g. in broadcasts, video production, and on professional camcorders. This interface is not used on consumer camcorders and mirrorless cameras but is available on PTZ cameras. SDI has two advantages over HDMI. Firstly, its twist-to-lock BNC connector is more rugged and cannot be easily pulled out during a production run, unlike HDMI. Secondly, the coaxial cable used in SDI is capable of sending quality video over distances up to 100m for 3G-SDI and about 40m for 12G-SDI. Your camcorder and mixer would need to support the 3G-SDI version if you are sending 1080p60 signal or 12G-SDI if sending 4K signal.

USB-UVC

This is a specification that supports streaming of video signals over USB cable. A camera that supports USB-UVC can be plugged directly into a Windows computer via USB to send video which may then be used in a livestreaming application such as OBS Studio. However, USB 2.0 is limited to 5m in length while USB 3.0–USB 4.0 is even shorter at 2–3m. Hence, this type of connection is restricted in terms of the maximum distance between your camera and computer.

HDMI Wireless Transmission Systems

For situations where running cables across floors is inconvenient, HDMI wireless transmission systems provide an alternative means to send your video feed from your camera to the mixer without requiring cables. Each transmission system for a single camera requires a transmitter connected to the camera and a corresponding receiver connected to the mixer. You would need a new pair of transmitter and receiver for every camera. The wireless transmitter significantly compresses the video to fit the available wireless bandwidth, which has a significant impact on picture visual quality. Manufacturers quote between 100m to 1km as the maximum distance, but these are measured in ideal environments and the devices almost never work up to the quoted maximum distance in practice. The system runs on the same 2.4GHz and 5GHz wireless bands used by Wi-Fi, so competition for wireless bandwidth can cause the signal to cut out. Majority of available systems have significant delay/latency, ranging from 40ms upwards, which can cause the audio to be out of sync with lip movement in video.

NDI (Network Device Interface)

NDI is a video-over-IP protocol developed by NewTek that allows devices to send, receive, and discover high-quality, low-latency video and audio streams over standard Ethernet networks. Instead of relying on traditional point-to-point cabling like HDMI or SDI, NDI enables multiple bidirectional video streams to travel across the same ethernet network used for everyday computing. Full-bandwidth NDI uses NewTek’s proprietary intra-frame compression to deliver visually lossless video at roughly 100–150 Mbps for 1080p, with latency around one frame. Lighter variants such as NDI|HX and NDI|HX2 use H.264 or H.265 to reduce bandwidth dramatically (down to 8–40 Mbps) at the cost of slightly higher latency. NDI has become widely adopted across broadcast, live events, corporate AV, education, and remote production because it replaces expensive cabling such as SDI with flexible network-based audio/video routing.