Hey everyone, here is a quick video showcasing 8 PS3 Eye cameras running in CL Studio Live on a single computer… There is 7 fixed cameras shown at bottom and 1 moving positioned above the checkerboard. Best part it all runs under 10% CPU!!!

Thats pretty impressive.

What are the specs of the machine running this?

This machine is an Intel i7 920 with 6GB RAM and NVIDIA 8800 GTX… A rather nice machine… But still, CL Eye Camera Devices take very little CPU… We have heavily optimized the data acquisition path from the sensor to the GPU for the lowest possible CPU usage per camera.

What is the configuration in terms of the usb ports?

We are using two Belkin F4U006 4-Port Travel USB Hubs with four PS3Eye cameras connected to each hub. Then those two hubs are connected to USB ports on the back of the machine.

AlexP

Forgot to ask: what are the framerates and resolutions?

They are all running in VGA (640x480) mode @ 30FPS.

AlexP - 18 October 2010 12:28 PM

They are all running in VGA (640x480) mode @ 30FPS.

Not bad. Is it possible to increase framerate/resolution or both, without decreasing the number of cams?

Thanks.

You could increase the frame rate but since PS3Eye has a VGA sensor obviously not the resolution (unless you interpolate). Due to the max USB 2.0 data rate limit you might have to rewire the cameras to some other configuration.

AlexP

That is a pretty good specification. I noticed that there were 8 cpu threads in the video and wasn’t sure if you were using a dual CPU setup. Out of general interest I would like to see how this performs on a laptop (with discreet graphics).

AlexP - 18 October 2010 12:56 PM

You could increase the frame rate but since PS3Eye has a VGA sensor obviously not the resolution (unless you interpolate). Due to the max USB 2.0 data rate limit you might have to rewire the cameras to some other configuration.

More questions, if you don’t mind.

1. What is the bandwidth limit in terms of framerate with the said resolution and number of cams, without changing the usb hardware?
2. What would be the “rewire” solution you mention?
3. Is it possible to get 60 fps in your hardware setup, without decreasing the resolution?

Thanks.

-8

The bandwidth limit will be that of the USB 2.0 controller (480Mbit/s on paper) if you were to doublet the framerate at the given resolution you are going to be attempting to send twice the amount of information in the same amount of time. therefore you would potentially only be able to run half of the given cameras for each USB controller at 60FPS (this would be 2 cameras per controller)

I believe the rewire solution would be to wire up 2 cameras per controller.

and yes, its possible however you may need additional hardware to support (more USB controller cards)

-K

The bandwidth limit as kshaaban said is 480Mbit/s. Of course you will not get that much in real life since there is some bandwidth overhead reserved by the protocol itself. A single PS3Eye camera capturing VGA @ 60fps will require about 140Mb/s. Therefore, it is not possible to run four cameras on a single USB 2.0 bus. For eight cameras you would need to have four USB 2.0 controllers and four two port USB 2.0 hubs. Then you would wire two cameras per hub.

AlexP

PS: For more info about USB bus and the PS3Eye camera please read this post.