vMix Backups & Redundancies

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Recently with the shift to virtual events, the prevalence of vMix in the live events sector has increased and more often I’m being asked what I recommend for stable vMix systems, ensuring the show continues even if there are system failures. Whilst there is currently no integrated main/backup functionality within vMix, these are some best practices.

Backup vMix PC

In production environments, I would always recommend having a backup PC to protect against hardware failure, software crashes & show config changes (there are many things that require a vMix restart). For all live in person events, I would run two VT playback machines, so it follows that for live virtual events you would use two vMix machines as so much of the production relies on it.

My preference is to run the same vMix show file on two identical systems, which also provides extra options for recordings, external outputs and streaming. If you would like the backup system to be a full hot backup, e.g. ready to swap with your primary machine at any time, I would recommend triggering them externally with Companion. There are of course many ways you can trigger vMix, but I have Companion the most reliable, also being IP-based makes it very scalable (and it will allow you to control many other aspects of your production).

If this isn’t a viable option in your setup, to add a layer of protection, it may well be worthwhile to output to OBS (or similar) via NDI from vMix running on a separate laptop.

vMix Main and Backup System with Streamdeck
vMix Main & Backup gallery at Stream Stage

Splitting Video Inputs with Backup

If you are running a backup system, you will distribute any locally captured inputs to the capture cards of the backup systems – this would include any cameras, presentation/Zoom computers, etc. that you would like to be present on both systems.

NDI inputs can be accessed easily by multiple computers on the same network, so that makes it an ideal way to capture presentations and external callers.

For smaller productions, you can simply use HDMI/SDI DAs to split the signal between your two systems – you may already be using a Decimator, or similar, to change the broadcast format of the video signal, which can also be used to distribute the signal.

For larger productions, I would stongly recommend using a matrix switcher, as this will make signal flow much clearer and add extra flexibility for feeding DSMs, production screens and recorders. It would also be ideal to use a matrix that interfaces well with Companion, as then more of the show can be automated.

Furthermore, I’ve found it can help to use an external production switcher when there are a large number of cameras on a show to reduce the load on the vMix operator and let the vision switcher focus on directing the cameras.

Splitting Audio Inputs with Backup

Not forgetting audio inputs will also need to be split between your main & backup system, a few ways to acheive this (in my order of preference):

  • Use a network solution such as DVS, AVB, (AES) or NDI
  • Embedded the audio over an SDI input which is already being captured on both systems
  • Use a separate audio interface on both machines

External Callers with Backup

If you are bringing in external callers via vMix Call, it will not work with two computers trying to host the call – this is because it’s a peer-to-peer connection. The solution to this is to have a single computer host the call:

  • Use an another vMix computer to soley handle vMix Calls to reduce the load on the main vMix machine, then you can still bring in all the individual calls via NDI to both main and backup machines.
  • Replace the vMix calls in the show file on the backup machine so that you have additional redundancy. This can be cumbersome to keep both showfiles up to date with each other.

For other internet call solutions, such as Microsoft Teams, Zoom, Skype, etc. I would bring these in via NDI – either using the built in facility in the software or with vMix Desktop Capture/NDI Scan Converter.

External Recorders

vMix External Output Window

Whilst you will likely get the best quality from the internal recorder in vMix, using an external recorder is a good means of protection against crashes corrupting the internal recording. They are also a great way to quickly hand over content to a client at the end of the event.

I would recommend making full use of the two external outputs in vMix: this could be as simple as outputting your TX with and without overlays, so that you have more flexibility in post.

If it’s a larger production, you may well want to use these for ISOs of your cameras/camera mix, fed through the matrix mentioned above.

Internet Redundancy

Assuming that you’re using as part of an online production, it’s worth considering what would happen in your lose the main internet connection.

If you have control over the network infrastucture, then the ideal is a dedicated line with an ADSL & 4G backup, with correct priorities configured.

Power Backup

It’s also worth considering what happens if you lose power to your production – this may already be covered by the venue you’re streaming from. However, I would always recommending having a UPS powering:

  • vMix PC (main & backup)
  • vMix monitors & peripherals
  • Network equipment, including 4G backup

Stream Redundancy

When streaming from vMix, I would recommend using a platform that supports a main and backup RTMP endpoint. Then using your main and backup vMix PCs, stream to both enpoints simultaneously.

Whilst this does require two vMix licenses, the benefit is that you can switch between the two PCs seamlessly whilst keeping the stream running.

If your platform does not support main & backup endpoints, sites like Restream will provide them and send the stream onto your platform.

In addition, if you are going to a custom platform, I would strongly recommend setting up a backup stream on YouTube, or similar, before the show starts, just in case there are issues with the bespoke platform.

Conclusion

One of the perks of vMix is that you can customise it to your specific requirements, but I think my ideal vMix configuration would include:

  • 2x vMix PC (main & backup)
  • Matrix switcher
  • External recorders
  • Gigabit network switch
  • 2x 4G backup on separate networks
  • 2x Streamdeck XL
  • UPS capable of powering the system for 10 minutes

It’s also worth considering if it’s possible to run your vMix instance in the cloud using AWS, or similar, however that’s beyond the scope of this post.