Cameras disconnect when I add new cameras (more than 3)

[mich_golden]

Hello everybody!

First of all, please receive my apologies for my low level of OBS knowledge and English :)

I am running OBS on a brand new MacBook Pro 13" (Apple silicon M2) with has installed Monterey OSX latest update.

My Obs version is 28.0.3 (64 bits).

I have this other hardware:

-GoPro Hero 3 with HDMI video capture adapter.
-Logitech C920
-2 x Trust Taxon 2K
-Hub USB TP-Link UH720

Well... when I start to run cameras one by one... adding font/video I can correctly reach to run at the same time 3 of them but when I plug the 4th camera 2 of the 4 cameras stop to send video (at least I can't see it in my screen because the video signal turns to black). Then, I can unplug and replug the cameras (it doesn't matter in which order or sequence) when I finally plug the 4th camera 2 of them turns video signal to black.

I would like to alert it is not a total disconnect of cameras, I mean, when I select the video for from the Logitech which has a light I can see to light turns on but the video signal remains black. When I select another font light on the webcam turns off.

I hope you can understand more or less my problem and could give support, tips and/or recommend me to do some tryouts.

I have attached a zip file with many of the log files from the past Wednesday when I was trying the 4 cameras and getting this problem.

Best, Mich.

 

[Lawrence_SoCal]

That sounds like the old USB Root Hub limitation issue. I'm not a MacOS user nor ARM-based CPU (M1 or M2) so can't be sure, but I suspect a similar cause as in x86 world regarding USB connections and bandwidth, with the ARM M2 CPU and associated chipset (there is only so much bandwidth available) and chipsets on consumer gear not designed to handle that many simultaneous cameras
So, without knowing more, I'd try the old testing approach of mixing the USB ports on the macbook.
do you have all 4 cameras plugged into 1 USB Hub? if yes, probably a bad idea (unless a high quality USB4 40gb/s specific doc) and even then, may vary depending on specific dock
You could try a quality Thunderbolt dock and its USB ports?
or probably 2 cameras (with 2 USB hubs) on each physical USB-C ports?

Then again, M2 CPUs aren't actually all that powerful, and doing real-time video rendering of 4 cameras, then compositing that ... may be simply overloading system?? (especially if trying to use maximum resolution on the GoPros) you'd need to use MacOS System Monitor for real-time hardware resource utilization monitoring (to check for CPU/CPU, storage I/O, etc limits).

Have you tried to use something other than OBS to see all four cameras at the same time? my go-to recommendation is to get audio and video working outside OBS first, then deal with compositing sources in OBS after that. That way you know if a hardware, driver, or Operating System issue, vs wondering if an OBS issue
Good Luck

 

[mich_golden]

That sounds like the old USB Root Hub limitation issue. I'm not a MacOS user nor ARM-based CPU (M1 or M2) so can't be sure, but I suspect a similar cause as in x86 world regarding USB connections and bandwidth, with the ARM M2 CPU and associated chipset (there is only so much bandwidth available) and chipsets on consumer gear not designed to handle that many simultaneous cameras
So, without knowing more, I'd try the old testing approach of mixing the USB ports on the macbook.
do you have all 4 cameras plugged into 1 USB Hub? if yes, probably a bad idea (unless a high quality USB4 40gb/s specific doc) and even then, may vary depending on specific dock
You could try a quality Thunderbolt dock and its USB ports?
or probably 2 cameras (with 2 USB hubs) on each physical USB-C ports?

Then again, M2 CPUs aren't actually all that powerful, and doing real-time video rendering of 4 cameras, then compositing that ... may be simply overloading system?? (especially if trying to use maximum resolution on the GoPros) you'd need to use MacOS System Monitor for real-time hardware resource utilization monitoring (to check for CPU/CPU, storage I/O, etc limits).

Have you tried to use something other than OBS to see all four cameras at the same time? my go-to recommendation is to get audio and video working outside OBS first, then deal with compositing sources in OBS after that. That way you know if a hardware, driver, or Operating System issue, vs wondering if an OBS issue
Good Luck

Hi,

First of all, many thanks for your extended and detailed answer.

I will add some information to clarify my problem so maybe someone could go deeper to help me.

1) My macbook only has 2 usb-c ports and if I want to power the computer I will have one of them busy with the ac adapter. That’s the reason I have purchased the powered 7 port USB tp-link hub.

2) BTW I guess I have done the tryout you are suggesting because I have attached 1 camera directly in one port and after that I have attached the hub in the other port and after connect the third camera in the hub (the 4th in total) 2 of the 4 cameras turns the image to black (disconnect).

3) At the same time I can open an application I use to setup the cameras (white balance, disable autofocus and so on) and while the OBS has 2 of the 4 cameras in black I can access the video of the 4 cameras on that application. I understand this means the problem is more focused on OBS software than Mac OSX/hardware problem (but I am not sure and that’s why I am here).

4) probably I have explained wrong about my setup. I have 4 scenes, each scene has a different video source (one camera for each scene). So I never need to get more than 2 video signals at the same time but transition time. So the max cameras sending video at the same time is 2. When I say cameras turn to black is because when I swap between scenes 2 of the 4 cameras remains in black. Same camera, same scene, if I unplug the 4 cameras and connect only 2 will get video signal again. After plug-in the 4th camera 2 of them get black again in their video source.


I hope you can understand my problem now and/or you could suggest me to do more tryouts or setup parameters.

Thanks in advance.

 

[Lawrence_SoCal]

1) My macbook only has 2 usb-c ports and if I want to power the computer I will have one of them busy with the ac adapter. That’s the reason I have purchased the powered 7 port USB tp-link hub.

tp-link is known for low-price, I've never heard that company referenced in terms of quality (and was well-known for being terrible many years ago. maybe they are better now?)
There are dock options that would provide both power and USB ports, so you don't HAVE to dedicate one USB-C port for power. And with a full battery, you could test with 2 hubs/docks

2) BTW I guess I have done the tryout you are suggesting because I have attached 1 camera directly in one port and after that I have attached the hub in the other port and after connect the third camera in the hub (the 4th in total) 2 of the 4 cameras turns the image to black (disconnect).

but with this result, the 2 USB ports may be connecting to a single USB Root Hub (equivalent), in which case, there may not be a fix.
Though using a quality USB4 or Thunderbolt dock may also solve the issue???

3) At the same time I can open an application I use to setup the cameras (white balance, disable autofocus and so on) and while the OBS has 2 of the 4 cameras in black I can access the video of the 4 cameras on that application. I understand this means the problem is more focused on OBS software than Mac OSX/hardware problem (but I am not sure and that’s why I am here).

Can you simultaneously see all for cameras video feed at the same time in the other app?

4) probably I have explained wrong about my setup. I have 4 scenes, each scene has a different video source (one camera for each scene). So I never need to get more than 2 video signals at the same time but transition time. So the max cameras sending video at the same time is 2. When I say cameras turn to black is because when I swap between scenes 2 of the 4 cameras remains in black. Same camera, same scene, if I unplug the 4 cameras and connect only 2 will get video signal again. After plug-in the 4th camera 2 of them get black again in their video source.

OBS has an option to turn off a source when not in use (but will then have a slight delay when you select a scene with a device that needs to be restarted). What I'm not sure of, is whether that option would apply to your USB cameras

I do NOT know... so definitely take the input of someone more knowledgeable on the Macs over my input
Good Luck

 

[.norman.]

Apple does a fantastic job of not revealing the computers actual specs. but it appears that is may be just 1 usb 4.0 controller. if that is the case i am not sure what your options are. typically the best you can do is 2 cameras per usb root hub (not an external device, this is the internal controller inside the computer). this may explain why you can only display 2 cameras at once.

(not a mac/apple guy either, just a guy that likes to help when he can)

 

[mich_golden]

Apple does a fantastic job of not revealing the computers actual specs. but it appears that is may be just 1 usb 4.0 controller. if that is the case i am not sure what your options are. typically the best you can do is 2 cameras per usb root hub (not an external device, this is the internal controller inside the computer). this may explain why you can only display 2 cameras at once.

(not a mac/apple guy either, just a guy that likes to help when he can)

Well… I am not sure if the problem is that you mentioned.

I will give you some additional info about my tryouts:

1) I have tried at the moment 7 different hub USB 3.0 or 3.1 and I can’t access to the video source for more than 2 cameras. When adding the third camera I get the video in black.

2) If I connect the third camera in the second port of the mac (2 cameras in the hub and 1 camera directly) I can get video from the 3 cameras.

3) This is the most annoying tryout. I have an old thunderbolt 2 Belkin hub with an Apple Original adapter from old thunderbolt to USB C. Unfortunately this hub only has 3 USB inputs so I have used it as a intermediar adapter. The result was very strange. If I attach the cameras to the “new hub”, the the new hub to the old belkin hub and finally the Belkin hub to the max through the thunderbolt adapter I can access 3 cameras. When I try to get video from the 4th camera I get black image… but now is running 1 more camera. If I connect the 4th camera to the Belkin hub I can access to it. So I am running the 4 cameras using only 1 port of the mac.


So If this embarrassing external architecture can run 4 cameras at the same time why a brand new usb hub can run directly 4 cameras?

How I can check what is mac handling the cameras and usb controllers? I see you can do it with usbview in windows… is there something similar for mac??

What can I do?

Thanks

P.S. After 2 hours on the phone with Apple support team they told be they don’t support me because OBS is not Apple app and the hub is not from Apple….. Apple always wins.

 

[.norman.]

P.S. After 2 hours on the phone with Apple support team they told be they don’t support me because OBS is not Apple app and the hub is not from Apple….. Apple always wins.

this is why i am a PC guy. I wish i was able to help more... i wish you the best of luck.

 

[Lawrence_SoCal]

So If this embarrassing external architecture can run 4 cameras at the same time why a brand new usb hub can run directly 4 cameras?

because Thunderbolt (TB) does NOT equal USB
Modern Thunderbolt (3 and 4) are PCIe extensions, which can tunnel USB, and some other approaches... but basically, not surprising at all that a USB hub would struggle in certain specific scenarios, but Thunderbolt would work. Then again, a current quality USB4 hub might perform the same as TB3/4 in this scenario

Ideally, you'd get your hands on a TB3 or TB4 hub, or a quality USB4 hub and test with one of those.

Good luck