7 cameras at the same time

[gburanits]

Hi!
I am planning to start a program on Twitch and for that I need to be able to transmit 5 or 7 cameras at the same time, all on screen (as if it were a Skype call but filmed with 7 live cameras).
I know that I can create scenes with several cameras simultaneously, but I wanted to know if it was possible with so many, and if I need any special device.

Another question is whether, if you can shoot with all these cameras, each one can be saved in a different file so that you can edit it later with that material separately.

If this can't be done with OBS, do you know of any way to stream on Twitch under these conditions?

Thank you very much!

 

[carlmmii]

You can absolutely use any number of cameras simultaneously... just as long as you have the hardware capability. The usual limitation you're going to run into is USB bandwidth, especially if using USB2.0 devices. USB bandwidth is allocated per host controller, so if you have multiple ports being run by the same controller, all devices connected to those ports will have to share bandwidth. For USB2.0 devices, usually only one camera can be supported per controller due to the bandwidth required.

There is a separation between USB2.0 and USB3.0 bandwidth allocation though, and USB3.0 has much more bandwidth available... but most USB3.0 devices use a lot more bandwidth due to sending uncompressed data.

Personally, I have 9 different cameras/capture devices, all operating simultaneously. 4 C922's are connected to a 4-channel USB PCIe card (4 dedicated host controllers), which meets the bandwidth requirements. A C922 and C920 connected to main motherboard USB, a camlink connected over extender/hub, and 2 PCIe capture cards.

So yes. Definitely possible, and only limited by bandwidth, and your CPU's ability to process that much data.


For the prospect of saving each to their own file... that is not really something OBS is set up to do. Each instance of OBS can only output whatever is composited within the scene -- no multiple output compositing, or raw recording. Also, with the requirement of only one program being able to access most capture devices, this means that doing using OBS would require a separate instance of OBS for each device, sending an output into your main OBS instance for stream (which is technically possible using NDI -- EposVox has a video explaining how to do this).

 

[gburanits]

Thank you very much for your time @carlmmii !! Really enlightening.

About the saving files' topic, is this the video you told me? https://www.youtube.com/watch?v=Pu5JFAIWH8Y
If so, let me see if I undestood correctly.

If I want to stream and record 5 imputs at the same time, I have to open 6 separate instances of OBS? So I would have:

1. Main streaming OBS
2. Cam 1 OBS
3. Cam 2 OBS
4. Cam 3 OBS
5. Cam 4 OBS
6. Cam 5 OBS

Main streaming OBS should have an imput of each OBS stances', is it correct?
Then I have to set each OBS cam instances to recording their own file? It won't fry my computer, right? LOL

If I understood correctly it's like nesting sequences on Adobe Premiere or After Effects, recording those internal sequences and streaming the "main one", right?

Sorry if my english is not good, spanish is my first language

Thank you very much @carlmmii !! I appreciate it