Hi Lael!

if you really want to avoid this latency issue, it will cost much more than just an ATEM which also has latency btw (a little less anyway).

If you just want to display the close up camera on speakers with no other information, you can use a video router like BMD Smart VideoHub for example.

If you need to add titles, make compositing, etc, the best option for no latency is to use an Analogway switcher or multiviewer.

Another option is to use an hardware switcher like Panasonics or Sonys.

As of vMix, depending on your hardware and your load, you can get an acceptable latency of 5/6/7 frames, as you can see in this video

However in order to avoid video loops, I'm using a 2 vMix setup here, where the main vMix ingests all cameras and does the production for streaming + providing inputs feeds via NDI to vMix 2 which handles the big screen presentation. With this setup, it's important to realize that some of the latency is not vMix related, but comes from the beamer itself.

Hope this helps
Guillaume

Thanks Guillaume,

At the moment, if we can't get an 'acceptable' latency, I think we will probably go for a hardware switching system. At the moment we are thinking the BlackMagic ATEM Production Studio 4K or the ATEM Television Studio HD. I understand they have latency, but I believe around 50ms total to screen if assuming sdi camera out - switcher - sdi - screen (depending on projector).

Is it possible to use vMix for creating titles etc and as a media input (eg, videos, slides etc) for the ATEM switcher? and to split the SDI output back to the vMix computer for recording and streaming?

From my brief look at Analogway after your comment they look beautiful and like they're probably out of the budget - please point me in the right direction if I missed something similar in the price range of the ones above.

I looked at your video, but there was no way to see the delay as it didn't look like you were running live feed back to the screen?

Yep sorry I should have indicated moments where you can see it. An example:
?t=27m15s

You will get more than 50ms with ATEMs. I just did a production with them, it's more like 4 frames, so around 100/125ms... And we had Led walls, not a beamer.

As of analogway, you're right. If you don't have a real budget, there is NO WAY to get 0 (or acceptable) latency.

The cheapest solution is certainly what I already told you: use a video router.

Guillaume

Thanks for posting - I saw your example from your post back in 2014 on these forums and was curious if it had changed. Are you recommending magewell cards over blackmagic ones?

What connections do you have in play for this from camera to projector? What have you done to decrease latency since then?

3 main reasons:
- the first one is I prefer to do the production recording and streaming over uncompressed signals rather than NDI feeds.
- I also measured that the loss is close to null when doing so. NDI inputs in vMix are immediately available to network. It's quicker to send an input via NDI to another computer than to display it to vMix output. The whole process is around 2ms. Saving 2ms is not enough to improve significantly the IMAG workflow imho (and not interesting enough to convince me to do the production on NDI feeds > point #1)
- at the time I did this particular production I also had hardware and licence considerations to deal with

I also remember it was easier to do that way as we had to provide audio to the PA for some media we had to deal with, so only vMix2 was plugged to the PA mixer while playing the media and at the same time providing vMix1 with the slides screen captures and the videos feeds over NDI. This way, audio and video sync was perfect for the audience in the venue. And it was easy for the audio guy to send everything but vMix2 to vMix1 via an AUX out.

Since that I could experiment another workflow using a SmartSwitch video router which gave us close to perfect results:

- all cams going to the video router
- vMix1 getting all cams from the video router
- vMix2 getting all cams from vMix1 over NDI (vMix was a laptop without capture card)
- vMix2 output going to the video router

- one destination output of the router going to the beamer directly
- then just have to "switch" inputs for this destination between cam2 (the close-up shot) and vMix2 output mainly for multiviews, slides, media, etc...

This way when the close-up shot is fullscreen on the beamer, there is no latency at all and about 6 or 7 frames for everything else which was only visible when using the close-up shot inside a multiview.

For better solution, using an Analogway is compulsary.

We have used a Tricaster for years with IMag events for very large corporate events and never had a complaint. vMix does have more. A BlackMagic ATEM is a hardware switcher with no scaling, it is as low as an AnalogWay. With scaling on, the AnalogWay is more.

All of this depend dramatically on the size of the venue Just the audio delay in a lager space is usually a much bigger issue.

My 2 cents, :-)

Steve

I wonder how much more Vmix Can be optimized to get even lower latency in the future? Tricaster is Software based as well just paired with hardware so it can be done..

Right now we are getting 6 frames of latency with our testing. That's with my personal Ursa mini's SDI going into my decklink quad, then into vmix, out the Nvidia 1050 Ti HDMI port, into an HDMI->SDI converter, Distribution AMP, then out to the projector and TVs from that.

I may try removing the Distribution amp and see how much that cuts down. We are looking at getting PTZs with NDI on them for when we buy cameras soon. It looks like the Blackamgic Decklink Quad is putting about 3 frames of latency in itself.

Beware that the Ursa Mini has some extra frames of delay on the sdi out!!

With NDI the at somepoint could become mostly a thing of the past though.

I'd love to see a Tricaster system demo someday if you guys ever came through the area, It's way way outside the budget for my church but my film production company keeps getting asked to do IMAG for concerts/touring acts so it may be something we have to look into down the road.

BTW, do you happen to know anything about this? https://forums.vmix.com/...aspx?g=posts&t=11644

The LC11 (or any of the NewTek control surfaces) use their own protocol for communication, they do not appear as a keyboard or MIDI device.

Kane Peterson
NewTek