I need some clarification. In the Settings - "Outputs / NDI /SRT" menu, there is a descption column. Next to e.g."1 Output" it says "Record / Stream /External". What does this mean?

I thought that it meant, that Output1 is "output" with the audio "Master" (as set in the gear icon) and it goes to "Record / Stream / External", but if I click the gear icon and change the bus from "Master" to "Bus A" it seems that recording still uses "Master" as input source.

So is description just a default description?



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Hello Michael,

The 4 “Outputs” are something like VideoBusse similar to the Audio.

The descriprion under Output 1 and Output 2 means as Follows:

Output 1: Record/Stream/External

The Video(&Audio) Signal goes internaly to the vMix Recorder wich is accessible in the main window as well this is the av-source for the 3-Stream Encoders wich, also the first one routable to an “external Output” wich is an SDI Output and requires an compatible SDI Device

Mostly you will Leave the Output (Master PGM/Mixer1) to the Output 1

Output 2 is also linked with the second external Output via SDiI and is supposed to use as an “AuxBus” on a traditional Switcher.

Output3 and 4 have no Links internally.

But only the 4Outputs (Or PGM Mixer1 in case of none Selected) are the selectable Return Source for vMix Call.

Also you can use this to Create NDI Feeds wich are not covered in the additional NDI Tab.
Like you want to Forward an Title Input or a custom Input MV via NDI.


Have Fun

So the gear symbol and the menu behind it is not only connected to NDI but mostl.

As i understand everything above the "enable SRT" checkbox is NDI related. You can select wich audio channels go in to this NDI Stream and boost the level with 20dB.
There is also the option to set things about NDI-Alpha channel and to rescale the NDI to a specific vallue.

Example for Rescaling: my webcam can only output 720p15 if i select this as the source of output 1 i can rescale it to the master framerate in your vmix. If you now check additional inputs on vis ndi you can cross check.
So i define two ndi sources in vmix one is my camera directly the other is vMixOutput1 labled. The Output1 NDI showing my camera has now 1080p30.

This is quite handy for outputting vMix Calls per NDI. If you output the call directly the NDI signal will change in framrate and resolution wich is not ideal for some hardware and software. Via Output1 to 4 you can scale them.


Everything below the SRT checkbox is related to SRT. You can addionaly send this Stream as an SRT signal though the internet wich is used for vMix to vMIx communication as an example. SRT is an Broadcast grade protocol and requires a propper network setup with forwarded ports and firewallrules in the reciever gateway.