Want to build 4X PIP for gaming on a 4K TV

[Mustang Guy]

I have been looking and researching all over the place to get this figured out. I have been building computers and servers since the early 80's, so I am not shy when it comes to that. The answers I found here when doing my research indicated that the people who know this stuff are right here! From what I see, you all are not only knowledgeable, but are willing to help numb-skulls like me.

Reason for project:

• Split a giant 4K projection screen into 4 quadrants for collaborative gaming.

Needed (as far as I know):

• 4 HDMI capture cards

• 4K capable output video card

Things on my mind about project:

• If the input from a gaming computer is 100FPS, what rate will be displayed on 4K TV?

• Is there an operating system or software that supports splitting these inputs?

• Is there an input card that is best suited for this?

• What should be avoided?

• If I want no more than 15ms lag, can this be built for any cost?

• Is there already a device or method that is available today to do this?
  Note: SKREENTV will be shipping no earlier than Dec 2015, so that's out.

• How much CPU power and memory does this type passthrough actually use?

• I'm sure I will think of more things, but for now, this gets me started.

I hope others get on board with this conversation. Although I do not have a 4K TV or projector yet, I am in the early planning stages of a beasty HT. I already have all the speakers which I bought from an iMax that had to be stripped before a flood. I know the screen will be acoustically transparent, and as large as 208" diagonal. I know I will install a 4K projector, even though I haven't picked one out yet. I game, and I have 3 adult sons who also game, and it would be awesome if this HT was capable of collaborative gaming.

[newpball]

At any rate this is going to cost you a lot of money.

An entry level 4K projector sets you back a least a few thousand dollars. The second issue is the framerate, 4K at anything over 30fps will become an issue but not impossible as HDMI is out for that framerate.

If you won't be happy with 60fps for your 1080p games your cost becomes exotic, I'd say 60fps is your reasonable limit.

The easiest way would be a Blackmagic multi-view unit, that sets you back about $1500

A Blackmagic Declink (4k or 4K) extreme should be able to capture the videos as well but then you have to mult-view in software. It won't be cheaper and is obviously more hassle.

Id' say you have to throw in at least $6000 to make this work excluding the computer.

[Mustang Guy]

At any rate this is going to cost you a lot of money.

An entry level 4K projector sets you back a least a few thousand dollars. The second issue is the framerate, 4K at anything over 30fps will become an issue but not impossible as HDMI is out for that framerate.

Thanks for your help! Prices come down every day. They just need to hurry up and get down to about $3,500.

If you won't be happy with 60fps for your 1080p games your cost becomes exotic, I'd say 60fps is your reasonable limit.

I agree, and 1080p60 is fine with me.

The easiest way would be a Blackmagic multi-view unit, that sets you back about $1500

Looking at that, I see the only input types are SDI. Most gamer PC's and Xbox and PS4's are all HDMI. Is there an adapter available from SDI to HDMI that can do 1080p60? IMO, this would be the best option if I could make it work.

A Blackmagic Declink (4k or 4K) extreme should be able to capture the videos as well but then you have to mult-view in software. It won't be cheaper and is obviously more hassle.

If I go this route, do I really need to be able to capture in 4K? The 4K cards they make take up two slots, and only have 1 HDMI in each. I would need 8 slots, and that doesn't include a video card for output. Blackmagic has the mini recorder that can do 1080i60, which might be the biggest compromise. $145 MSRP each is a lot better than $1000!

Id' say you have to throw in at least $6000 to make this work excluding the computer.

Hopefully the $600 + option (4 x $145 mini recorders) will do. The output card could be a consumer graphics card like a higher level Radeon or something. I will have to check to see which ones can do 4K at 60 frames.

[lingyi]

As knowledgeable and helpful as most of the posters here are, recommend you head over to AVSForum.com with your questions. They have forums for Gaming and Projection (including High End and Ultra High-End which is likely where you're headed for your needs).

[Mustang Guy]

As knowledgeable and helpful as most of the posters here are, recommend you head over to AVSForum.com with your questions. They have forums for Gaming and Projection (including High End and Ultra High-End which is likely where you're headed for your needs).

Good idea. Thread posted here: avsforum.com/.../want-build-4x-pip-gaming-4k-tv...

[newpball]

Check this software, it's open source:

http://www.casparcg.com/

[Mustang Guy]

Check this software, it's open source:

http://www.casparcg.com/

I was looking at the source code just now. video_format.cpp shows resolutions and frequencies supported, and the top is 4k30Hz.

"DEFINE_VIDEOFORMATDESC(video_format:2160p3000 ,3840, 2160, 3840, 2160, field_mode:rogressive, 30, 1, boost::assign::list_of(1600), L"2160p3000"),

This makes me wonder. Is 30Hz playable?

[pandy]

For 15 ms lag you need at least 67fps output but realistically you need to double this (four inputs are asynchronous, they need to be captured, aligned as difference can be up to 1 frame and sent to output so you need at least twice faster processing) so based on this requirement HDMI output is no longer option.
Display Port + FPGA based solution http://www.xilinx.com/applications/broadcast/digital-television.html , http://www.altera.com/technology/high_speed/protocols/displayport/pro-displayport.html - developer kits are available .

Software solution is possible but latency will be higher and new problem to be introduced likely (jitter)...

[Bjs]

Why 4k cap ? ... when games max at 1080i ?

The best solution is to buy 4 x Full hd tvs and arrange them in any order on wall ... cheapest, less cables, 0 lag, more enjoyment.

Then you can setup video (movies) to be displayed across all 4 panels

2 projects with one stone as they say

[Mustang Guy]

For 15 ms lag you need at least 67fps output but realistically you need to double this (four inputs are asynchronous, they need to be captured, aligned as difference can be up to 1 frame and sent to output so you need at least twice faster processing) so based on this requirement HDMI output is no longer option.
Display Port + FPGA based solution http://www.xilinx.com/applications/broadcast/digital-television.html , http://www.altera.com/technology/high_speed/protocols/displayport/pro-displayport.html - developer kits are available .

Software solution is possible but latency will be higher and new problem to be introduced likely (jitter)...

Pandy,

You are definitely the go to guy for this. I spent about 15 minutes just looking up all the acronyms (ASIC, ASSP, SoC, FPGA, etc). Then I studied the architecture needed to implement this. Then I looked at the 7000 evaluation kit price ($2,495) and the Stratix IV GX FPGA Development Kit price $4,495). Then I looked at the DisplayPort configuration. On top of all that, there isn't a projector that doesn't cost less than 20 moon rocks that can handle the output.

Conclusion, the technology isn't there yet, and I am not rich enough to hire the 30 people to build and trouble shoot this. Let alone the jitter and timing issues or the overhead dealing with them would create.

Your reply has been very enlightening. I have learned a lot I did not know. One thing is clear, and that is that SkreenTV will not be a good choice for quad gaming.

In 5 years or possibly less, this will be child's play. Until then, quad gaming will be relegated to an XBOX and Halo, or their ilk.

Make it a good day, and thanks again for your valuable feedback!

[pandy]

Pandy,

You are definitely the go to guy for this. I spent about 15 minutes just looking up all the acronyms (ASIC, ASSP, SoC, FPGA, etc). Then I studied the architecture needed to implement this. Then I looked at the 7000 evaluation kit price ($2,495) and the Stratix IV GX FPGA Development Kit price $4,495). Then I looked at the DisplayPort configuration. On top of all that, there isn't a projector that doesn't cost less than 20 moon rocks that can handle the output.

Conclusion, the technology isn't there yet, and I am not rich enough to hire the 30 people to build and trouble shoot this. Let alone the jitter and timing issues or the overhead dealing with them would create.

Your reply has been very enlightening. I have learned a lot I did not know. One thing is clear, and that is that SkreenTV will not be a good choice for quad gaming.

In 5 years or possibly less, this will be child's play. Until then, quad gaming will be relegated to an XBOX and Halo, or their ilk.

Make it a good day, and thanks again for your valuable feedback!

Technology is available but it is expensive, yes development is not so easy but doable (my friend running own company and they doing such things in FPGA - something with 4 HDMI inputs and h264 compressed gigabit Ethernet output) - most of things you need are already done and available as product - so called softcores - blobs of code to be used in FPGA to perform particular HW functionality, side to this you have support engineers (Xilinx, Altera, Lattice), forums etc - doable but yes - it will cost You more than 10 - 30k $ - some expectations need to be realistic and this was my point - for example 15 ms latency divide 1000 by 15 and you will see how many frames you need to meet this, everything is like this.
Software is doable, 4 input HDMI... difficult - single HDMI input boards are available (so 4 boards), special software written for this doable but not sure what kind of OS will be suitable (regular OS may be suboptimal - perhaps realtime patched Linux will be OK) - managing 4 video streams, combine is not specially challenging stuff (as HDMI PCIe card can push data by DMA to main memory or even to GPU memory), challenging is amount of data that need to be sent, combined and feed to card - GPU and mother board should have required bandwidth but you need a software - clever to deal with amount of data in realtime.