4k 60fps multicamera livestreaming

Dear forum,

I'm just about to jump with both feet into the world of 4k 60fps multicamera livestreaming, and I

just want to make sure I've gotten all the info down correctly.

Equipment:
2 Mini Ursas connected to an ATEM 2 M/E Broadcast Studio 4k with 12g SDI cables.
2 Condenser Mics connected to an RME interface with XLR cables.
A computer with a Thunderbolt-port.

I have a few concerns regarding this setup.
1. Can I simultaneously record the videostream to a harddrive, and is compression/encoding optional?
2. Can I simultaneously record the audio to a harddrive?
3. Can I run the audio through for instance Logic Pro X, and apply plugins, which then is returned
fully processed to the livestream with 100% sync to the video?
4. How fast of an internet connection is required for such a high quality stream?
5. How much harddrive-space is required for a 1 hour recording?
6. How powerful does the computer have to be? Will for instance a MacBook Pro with i7 2,7ghz with
turbo upto 3,6ghz be enough to run such a setup smoothly and with proper overhead?

In advance, thank you for your help!

2 ursa's connected to a 2ME broadcast studio 4K.. Oke but how do you want to capture it then? You did not specify that..

Running audio seperated of the video, process it trough a computer and put it back out to embed under a live stream and have it 100% sync... Not very simple......
Try to process the audio in hardware and embed it on your videomixer, Keep in mind that you have to delay the audio a bit to get it 100% lipsync.

Not sure what you want to do with that thunderbolt on your computer.. Or are you into buying a UltraStudio Thunderbolt?? (Which is 1 of the few ways to capture 12G sdi.. Or you need a Decklink 4K Extreme)

What software are you planning to use to stream 4K video? It all depends on codec's on how much bandwidth you need.. But 4K and good quality with some headroom i think a stable 20Mbit minimum...

And after all when you streaming in 4K to internet.. Which platform for reaching your audience will you use..? (This is important for the stream software also..) And how much of the users that will watch the stream in 4K ?? I don't have 4K monitors on my desktop.. Do you?

1. Can I simultaneously record the videostream to a harddrive, and is compression/encoding optional?

Depends on your encoder. Most will allow you to record the "line cut" to disk at the same time you stream. Since you plan on encoding 2160p60, this is extremely CPU intensive.

2. Can I simultaneously record the audio to a harddrive?

Generally audio will be baked in to the video recording. If you want to record isolated audio you will need to run a software recorder like Audacity or similar, or use a hardware solution.

4. How fast of an internet connection is required for such a high quality stream?

I would want 50 megabits per 2160p60 stream. This is extremely CPU intensive, again.

5. How much harddrive-space is required for a 1 hour recording?

Encoded at 50 megabits H.264 will be about 250GB.

6. How powerful does the computer have to be? Will for instance a MacBook Pro with i7 2,7ghz with
turbo upto 3,6ghz be enough to run such a setup smoothly and with proper overhead?

No way. You will need to encode the video on something else.

Xtreemtec makes a very good point about your platform. Of the big video streaming platforms, only YouTube Live has support for 4K to my knowledge, and that's in beta.

Hi Jack and Xtreemtec,

and thanks a lot for your time! This is exactly why I felt the need to ask in a forum before plunging in, since my experience with this is limited. The whole point of buying equipment which is ready for that sweet 4k revolution, is of course for future-proofing. I'm aware that as of now, there are limitations to 4k streaming, but I want to make sure that the investment will pay off in a couple of years.

So, building a rig with the necessary cpu-power is just a budgetary matter. Internet speed is no problem (300Mbit).

My mistake regarding the thunderbolt port, I just assumed you needed the full power of the thunderbolt 3 in order to process the vast amounts of data that is 4k 60fps video recordings. Are you saying that a BlackMagic UltrastudioExtreme 3 will be enough for a 2-camera 4k 60fps live stream solution over thunderbolt 3?

I (hypothetically) want to capture the streaming-output directly to external harddrives. Do I need an additional BlackMagic box for that purpose?

Regarding the audio sync, I'm guessing that you manually have to calculate the delay from a program like Logic Pro X, but that the delay will be constant, and therefore it's only necessary to calibrate the delay before starting the live stream session?

A private YouTube video is the goal for now, but we might move to different platforms in the future. As I understand it, Youtube already compresses the video to such an extent that it might not be cost-efficient to pursuit 4k 60fps streaming, but I want to prepare for the future with this build.

So many questions, and I apologize for my ignorance.

I think the problem is that 4K streaming will not be a big thing for the upcoming 3 years.. As not to much people and sites like youtube will support it to the fullest..

You can spend a whole lot of money now into 4k. ( i know.. i have a Future proof OBV full 12G 4K. ) But that time 4K streaming will rise and be more supported your hardware is out of waranty and there is a lot of new hardware that will support 4k and it will become cheaper..

Let me be clear that i don't want to stand in your way by the big 4K dream / adoption.. For my OBV i was like it's worth to me to be the early adopter while spending triple as much money as i will for the same sort of setup in 3 years.. But for a OBV were i already have some jobs in 4K (registration of live concerts) it was worth it.. For 4K streaming i have my doubts.. HVEC 4K codec is just out a few months.. Youtube is experimenting with 4K streaming.. But nobody else does yet or isn't ready for that step yet.. If i would bet my money i would invest in HD first.. Make some money out it.. And upgrade in 2 or 3 years when 4K live will rise..

By multi camera, do you mean someone switching live, or are you going to use the YouTube multi-camera feature?

So, building a rig with the necessary cpu-power is just a budgetary matter. Internet speed is no problem (300Mbit).

Typical i7 should be able to encode 2160p60 H.264. It worked (barely) on a 5 year old desktop here.

My mistake regarding the thunderbolt port, I just assumed you needed the full power of the thunderbolt 3 in order to process the vast amounts of data that is 4k 60fps video recordings. Are you saying that a BlackMagic UltrastudioExtreme 3 will be enough for a 2-camera 4k 60fps live stream solution over thunderbolt 3?

I don't have any UltraStudio units so I am not sure, but you may not be able to use multiple inputs at the same time.

I (hypothetically) want to capture the streaming-output directly to external harddrives. Do I need an additional BlackMagic box for that purpose?

You could use HyperDecks to record the SDI out from the UltraStudio, but that wouldn't include any graphics or switching done in the encoder, and they're not cheap. Software encoders will let you record the "line cut" to disk in H.264 while streaming it.

A private YouTube video is the goal for now, but we might move to different platforms in the future. As I understand it, Youtube already compresses the video to such an extent that it might not be cost-efficient to pursuit 4k 60fps streaming, but I want to prepare for the future with this build.

If it's not a client requirement I would wait, personally. It's much more expensive to do UHD workflows, the audience is small, and we're only just getting support for it. It's fun to play with the toys, though

Not A BMD solution but take a look at Vmix - it'll do everything you are talking about at a fraction of the cost - your real problem though will be bandwidth - you really need need about 20Mb - so a 40-50Mb "guaranteed" pipe.

Why 60fps? is it a fast moving sport? Even going to 25fps would make a huge difference in what you need to buy and bandwidth.

Cheers
David

Guys, you are fantastic! Thank you so much for your wonderful help.

@Extreemtec: Congrats on the 4k OBV, and thanks for the suggestion on waiting for some years before upgrading. The timing for choosing 4k for our first production equipment seems less than ideal. We'll go back to consider 1080p 60fps. This also gives us time to improve our techniques, while the technology for 4k may improve considerably in the coming years.

@Jack Fairley: I'm planning on live switching. Thanks for the suggestions on equipment and internet bandwidth. We will consider holding on a bit before going the 4k route. Even though I love my toys!

@David Hutchinson. Thanks for your suggestions! It's quite fast moving, and we really want to capture the details of the movement. The smoothness of the 60fps is too nice to neglect.

It looks like 1080p has returned to the menu for now. Thanks a lot for your help!

Cabling may be an issue do to requirements to do 12G-SDI.
From Blackmagic Design Support Notes
It is important to use a good quality HD cable with 12G-SDI products. As an example, we have used an industry standard Belden 1694A cable when testing our 12G-SDI products.
Distance for cable lengths are:
3G-SDI 100 meters
6G-SDI 80 meters
12G-SDI 50 meters

I find similar question in another forum:
https://steamcommunity.com/groups/homes ... 942357060/