Audio-to-NDI: Operation

Operation

1. Refresh devices. Select the USB/Thunderbolt interface and input count. Capture covers hardware channels 1 through that count; mute channels you do not want to include. An interface must support 48 kHz float capture with that channel count. Inputs beyond 32 are not available in this release.
2. Give each channel a useful label and set the NDI source name. Click Monitor inputs to check input/output meters without advertising an NDI source. Preamp gain and phantom power stay on your hardware controls.
3. Stop monitoring, then click Start NDI. Adjust gain, pan and mute while sending. An unmuted centered mono input feeds both output channels at −3 dB per side (constant-power pan). Inputs are summed without an automatic limiter or normalization; lower gains if the output reaches 0 dBFS. Meters show PCM dBFS. NDI float output uses SMPTE reference scaling: −20 dBFS corresponds to NDI 1.0 (+4 dBu). Match the receiver's reference level.
4. In OBS with DistroAV/NDI support, create an NDI source and select the advertised name (usually Computer (Source name)). It has no picture. Include it in each needed scene or a shared audio scene, unmute its Audio Mixer channel and assign tracks. Select stereo in OBS. Leave OBS audio monitoring off unless needed to prevent a feedback loop. Production Truck's local NDI discovery can also list this sender; choose the exact source name. Audio-only sources have no camera preview or PTZ.
5. Stop closes capture and removes the NDI sender. Exiting the app also stops transmission. Stop remains available if account verification fails. No capture/transmission or reboot startup is enabled by default. Workstation may lock this app into kiosk mode using its existing administrator controls.

Settings are private per user under ~/.ga360-audio-ndi/audio.json; updates preserve them outside installed source. Device identity is checked after reconnect/reboot; an ambiguous or missing interface requires re-selection. A disconnected device/native crash becomes a visible error with cleared meters, not an automatic switch to another microphone. Drop/overflow counts indicate interruptions; stop, check load/permissions/interface and restart. Capture uses bounded queues and an isolated native worker. Source/device/channel count changes require Stop. This first release uses one physical interface at a time, mixes to stereo, and does not offer independent NDI senders per input, discrete multichannel output, resampling, network clock synchronization or camera lip-sync compensation.

Hardware/NDI receiver and native macOS tests remain necessary on the target production machines. Automated tests use simulated capture and SDK calls.