1 PC, 24 HDMI Inputs

[eesean]

Hi,

 

I'm looking for a solution to simultaneously record the output from 24 HDMI video feeds (1080p24fps) and stitch them into a single output. Here's what I've gathered:

 

Literature Review

The most relevant LTT forum post was from 2022 with no conclusion:

 

Capture Cards

I've narrowed down several consumer capture cards exist on the market that allow 4x HDMI FHD input:

1. Magewell Pro Capture Quad HDMI - PCIe Gen2 x4: https://www.magewell.com/products/pro-capture-quad-hdmi
2. Blackmagicdesign DeckLink Quad HDMI Recorder - PCIe Gen 3 x8: https://www.blackmagicdesign.com/products/decklink/techspecs/W-DLK-36

 

Motherboard

Theoretically, a Threadripper Pro HEDT motherboard with sufficient physical slots should have enough PCIe lanes to support 6 of any of these cards.

For example, this Asus motherboard supports up to seven PCIe Gen3 x16 physical cards: https://www.asus.com/sg/motherboards-components/motherboards/workstation/pro-ws-wrx80e-sage-se-wifi/techspec/

 

Does anyone have any experience with a similar setup and could share any other spec I may have overlooked?

 

Thanks,

eesean

[Needfuldoer]

What exactly are you trying to accomplish and what's your budget?

 

Do all these recordings need to be independent, full res clips?

[eesean]

17 minutes ago, Needfuldoer said:

What exactly are you trying to accomplish and what's your budget?

 

Do all these recordings need to be independent, full res clips?

I'm trying to combine multiple video feeds into 1 high res stream over RTSP for networked users. They do not need to be independent clips.
Tentatively, I'm considering using OBS to combine these inputs into the output stream.

[Needfuldoer]

31 minutes ago, eesean said:

I'm trying to combine multiple video feeds into 1 high res stream over RTSP for networked users. They do not need to be independent clips.
Tentatively, I'm considering using OBS to combine these inputs into the output stream.

Sounds like what you really want a multiviewer. Those get expensive fast (especially since they're almost all SDI which means you'd need converters on all your sources), but we can fake it with some HDMI quad splits.

 

You'd need six of these:

https://www.amazon.com/OREI-Switcher-Seamless-Support-Security/dp/B08FBLLJD9

 

And one of these:

https://www.amazon.com/OREI-Switcher-Seamless-Support-Security/dp/B0BQ1XK82T

 

Feed your inputs in batches of four into the 1080-out quad splits, then feed four of those into the 4K quad split. That will give you 16 inputs on one 4K channel. The other two 1080 quad splits can go right into your capture PC. That will give you all 24 inputs at half resolution into just one DeckLink Quad HDMI card. Once you've got these inputs in OBS, you can duplicate and crop them if you need to rearrange the individual videos to fit your stream.

 

A regular desktop platform should be able to do this if you add a GPU for hardware video encoding.

[eesean]

On 10/16/2024 at 5:35 PM, Needfuldoer said:

Sounds like what you really want a multiviewer. Those get expensive fast (especially since they're almost all SDI which means you'd need converters on all your sources), but we can fake it with some HDMI quad splits.

 

You'd need six of these:

https://www.amazon.com/OREI-Switcher-Seamless-Support-Security/dp/B08FBLLJD9

 

And one of these:

https://www.amazon.com/OREI-Switcher-Seamless-Support-Security/dp/B0BQ1XK82T

 

Feed your inputs in batches of four into the 1080-out quad splits, then feed four of those into the 4K quad split. That will give you 16 inputs on one 4K channel. The other two 1080 quad splits can go right into your capture PC. That will give you all 24 inputs at half resolution into just one DeckLink Quad HDMI card. Once you've got these inputs in OBS, you can duplicate and crop them if you need to rearrange the individual videos to fit your stream.

 

A regular desktop platform should be able to do this if you add a GPU for hardware video encoding.

This seems to be able to handle what I need it to. Thanks for the detailed response!