Multiple Video Grabbers on USB hub

Is is possible to have multiple video converters like Composite to USB and HDMI to USB to run concurrent on a USB hub connected to a PC?

I tried with two USB hub models with one at USB 2.0 and the other 3.0 and they would not allow the PC to capture from 2 Composite to USB 2.0 at the same time.

What kind of bandwidth does one of those converters use?

Even leaving other issues with those simple USB Hubs aside, that might be the main problem.

I don’t have the specs with me right now but I assumed a USB 3.0 could handle 2 USB 2.0 connections at max bandwidth rated for 2.0

AFAIK a USB Hub works by having the host talk to devices at different times, since they can’t use the same lanes at the same time.
I could imagine that the driver you’re using for those might be trouble.

But I have seen USB Hubs have issues Bandwidth-wise for that reason too where they shouldn’t.

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Hi, I don’t have experience with it, but I am intrigued;
The USB devices would be video sources, right? And you would like to receive/process a couple of sources at the same time?
Which software are you using to receive the input?

And is the problem on the side of the bud (only transferring one stream) or the receiver side (only reading from one source?)

I am thinking like OBS might be able to handle several streams, or CCTV cameras have several streams into one piece of software?

Could it be that each source, needs to be on it’s own USB controller/bus? And all USB sockets might all be on one controller?

Sorry I can’t help, but sounds an interesting problem

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You can use both video sources if plugged in different USB ports, however for the solution we’re designing we need to use an USB hub so save on USB slots going to the computer.

I’m using OBS and VLC for testing, but I’m going to use OpenCV with this project. Tried all 3 approaches but when one video slot is in use, the other in the USB hub becomes unreachable giving read error if I try displaying the video.

If I plug them in different USB ports they work at the same time. But still when plugged in the USB HUB you can see the devices plugged in in the Linux device tree.

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Same as Trooper_ish here, no idea but fascinated.

Have you tried using a USB-Dockingstation (of the compact/travel variety)? Those usually have enough smarts in them to handle all USB-ports running higher data rate devices.

No but they also take up too much space for what I need unfortunatly.

Currently I tried using something very similar to this but different brand.

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Long shot:
Have you checked power draw of the hub & grabber setup?
One of those cheap USB-meters is more than enough:

The reason I said about USB controllers, is because DIYPerks YT Chanel did a home made camera setup with USB cameras, but it would not take multiple streams on each controller.
So he added a pci device with it’s own controller. (Does not help, But this is the project I was referring to)

But he was able to get two, low quality streams per USB2 controller, not just one.

Nice to hear about the project though bud, sounds cool, hope you get it working!