NDI / OMT

The exit that puts a chosen source on the network. How to add a row and pick a source is Outputs and Settings → Outputs.

Transport and encode

Transport is OMT or NDI.

OMT can choose an encode path. The default is CPU (Recommended).

CPU (Recommended) is the default OMT encoder. Use it for Mixing Unit Program and other mission-critical program video. If CPU encode is selected, the frame is read back as UYVY, then converted to the VMX codec and sent on a dedicated CPU send thread.

GPU is an auxiliary OMT encoder. It can offload work from the CPU, but it loses more than CPU, so use it for Multiview and other auxiliary video. GPU encode keeps the frame on the GPU and converts it to VMX.

NDI is always a CPU path.

One thread is assigned per output. Video frames are sent at that output’s frame rate, not as soon as compose finishes. Resolution and frame rate are per output in Settings → Outputs. eiviz paces NDI submits on the shared media clock. The NDI SDK still requires one clock; audio clocking blocked send_audio, so video stays the required SDK clock. OMT encodes a VMX bitstream once per Output and fans that bitstream out to receivers. The pinned openmediatransport-rs revision already shares one encoded Arc and writes peers from a bounded background queue (depth 4, drop when full, 40 ms video write timeout). Ten receivers do not mean ten encodes.

Each OMT output can skip VMX encode when no receiver is subscribed. The default is on. Turn off “Skip encode when there are no OMT receivers” in Settings → Outputs to keep encoding. NDI ignores this option.

Audio

Audio is one Mixing Unit’s MU Bus, or None (no audio).
When Multiview is selected as the video source, audio cannot be sent.

Device mix is Audio, ASIO, and related. Network PCM is taken from that internal mix.