Multiple Cams in OBS
- Thread starter ElioAdler
- Start date
FerretBomb
Active Member
USB supports more than just 2 cams, but you may need to install a PCIe USB expansion card to have more UHCI/XHCI hubs to allow the bandwidth needed. There are companies that sell 4-port, 4 host-controller cards that each port has full USB 2.0 bandwidth available to it.
For HDMI cameras, there are internal PCIe capture cards that will skip the USB bus bottleneck entirely; Magewell sells a 4-port HDMI capture card that supports 4 1080p60 inputs simultaneously. Though it DOES require a solid CPU to handle decoding and ingesting four 1080p60 video streams at once.
NDI can take up a HUGE amount of network throughput as well... even a gigabit network can be overwhelmed pretty easily, and you may need to run a second dedicated cameras-only network on a PCIe NIC to avoid issues with traffic shaping on your streaming output.
If you're on a laptop... well, just one more reason laptops are not recommended for streaming setups. They're extremely limited in function and expandability.
For HDMI cameras, there are internal PCIe capture cards that will skip the USB bus bottleneck entirely; Magewell sells a 4-port HDMI capture card that supports 4 1080p60 inputs simultaneously. Though it DOES require a solid CPU to handle decoding and ingesting four 1080p60 video streams at once.
NDI can take up a HUGE amount of network throughput as well... even a gigabit network can be overwhelmed pretty easily, and you may need to run a second dedicated cameras-only network on a PCIe NIC to avoid issues with traffic shaping on your streaming output.
If you're on a laptop... well, just one more reason laptops are not recommended for streaming setups. They're extremely limited in function and expandability.
deFrisselle
Member
On USB the bus bandwidth is a limiting factor You might be able to do two 720p cam on one USB bus, especially USB3, but 1080p cams will have to be on their own buses to give the needed bandwidth for each cam You can either add a USB PCI card or a capture card
My setup has 5 cams, three usb cams and two IP cams
r1ch.net
My setup has 5 cams, three usb cams and two IP cams
Managing USB bandwidth with USBView | r1ch.net
Find out how to make your USB devices perform optimally by moving them to less saturated controllers.
Lawrence_SoCal
Active Member
Just to clarify, for my PTZ AW-HN38 camera NDI HX consume about 20-30mb/s per camera (at 1080p60fps), but HX then needs more CPU to handle the extra decompression (vs regular (compared to high/HX) efficiency NDI which will take a bit over 100mb/s for same stream)
So, as @FerretBomb mentions, each camera type has its own consideration.
You mention only 2 cameras at a time... let me guess, you were using USB cameras, right? ie most likely ran into USB hub limit, not OBS (either that or PC 'horsepower')
To that you can add whether, depending on camera, you will have a switcher of some sort in front of streaming PC... that is, will OBS computer have to deal with (process) all 4 video streams all the time, or will you externally limit to only a single desired camera at a time? This obviously has significant resource implications (RAM, CPU, GPU)
Though you aren't asking specifically about computer s[pecs, and you have answers above about getting that video feed to OBS, then next issue is the PC specs themselves. You haven't mentioned how long you want this computer to last, and whether always limited to 1080p. And what else you want to do with this PC if anything. For example, any video editing?