Using two webcams at once

[Solorize]

Hi

Quick update.

I still had the same problem with only one webcam working until i plugged the new one in and then the 1st webcam froze.
This also happend when running VisionGS =(

So I decided to uninstall the new webcam drivers that I had installed then rebooted and had a look in my BIOS and noticed
that the USBs had some of ther IRQ's the same.

ie. three of them were on 11, one was on 10, another was on 5 etc..

So I tried to change them but it only gave me a couple of options and even then when I changed
one it also changed another one of them to the same number !?! So I guess they must be linked some how?

Anyway, I decided to exit the BIOS and not save the changes, went back into Win XP and unplugged the new webcam
and moved it to another USB port..... Now this time when it was plugged in it did not freeze the 1st webcam =)
But it would not display the new webcam.

So I then rebooted the machine and load up my 1st webcam in Yawcam, then once that was working I started the new webcam
in another instance of Yawcam.

Now I have the 1st webcam displaying and working as it should, with the second webcam just showing a blank black window =(

I then adjusted the format settings settings for the 2nd webcam from 640x480 to 320x240 and volia it started displaying =)
But if I try and increase the resolution it just goes blanks again =( even tho the webcam supports a higher resolution!

The only other thing I can think of is that I am running out of graphics memory and therefore I cannot display at a larger size
along with my other webcam running at the same time. I only have onboard graphics, so I have just ordered a stand a lone
graphics card to see if that will help.. but I am now started to clutch at straws as am running out of options =(

[slashmusic]

I have also only a small computer (has the size of a book and only 15 W power consumption) with a build in Graphic card running on Windows 2003 Server with a lot of applications started.
I am using VisionGS and 2 Webcams. One is an USB webcam one is and WLAN Webcam. I don't think this is related to the Graphic Memory.
Smaller Buildin Graphic Cards should use Shared Memory.
I can face an increased CPU consumption once both Webcam pictures (Live view) is visible on the desktop.
Some month ago, I also used 2 USB Webcams at the same time and had no problems.

but anyway, good luck when using an external graphic Card
-jan

[mcrossley]

I have no experience with multiple webcams, but... It may be you are running out of bandwidth on the USB bus. Often separate physical ports are internally linked to the same USB hub and so share bandwidth - but not always. So try a couple of things:

1, move one webcam to a different USB port if possible (if you are savvy enough you can see in Device Manager how the USB devices are connected, try the 'Devices by connection' view).

2, try reducing the streaming frame rate from the web cams - this is not the same as your capture rate - this together with the frame size has a big impact on bandwidth utilization. (as a bonus the image quality often increases with reduced frame rate as many devices (usually USB1.1 device) apply increasing compression to the image stream to fit into available bandwidth.

[Solorize]

Thanks to you both for your replies,

I have had a look at the devices by connection:



I had tried the cameras in different USB ports and with the ones they are in now
is the only way I can get them to display at the same time.

FYI. I have the following connected to USB ports and have juggled them around
to see if it makes any differnece, and also tried with just the two cameras connected ony.

External HDD

UPS

FineOffset base unit

MS Lifecam

Hue HD webcam



I have also tried dropping the frame rate;

MS Lifecam = 7.5 fps

Hue HD cam = 30 fps
(I cannot get it to drop down lower, even when i select it, it defaults back to 30 fps)

I may be able to get it down further if I loaded the HUE webcam drivers back on, BUT these drivers interfere somehow with
my MS Lifecam and stop it from working.


My next problem is that the Huecam "over exposes" the image big time and as I dont have the drivers loaded I cannot
control the Exposure. The image is fine when it's night time, it seems to expose correctly, but as soon as it starts turning
daylight the images whites-out, see below. The only thing I can think of is that when I was at home and set it up when its was dark
the camera up and it must have set its exposure to display as much of the scene as it could (say +10 exposure), but
when the daylight starts to come up it doesnt change the exposure setting and therefore over exposes the scene buy the
+10 it was using when it was started in the night, therefore whiting-out the image.

One thing I will need to try is seeing if I can disconnect and then reconect it in the daytime so it sets its exposure correctly
for the daylight and displays it correctly, then when it starts to get dark the image gets darker untill at night its wont display
anythhing. Obviously I will need to wait until the weekend as its dark when I leave the house in the morning and dark when
I get home at night to try this theory out.

The other thing I was thinking was to put a polarising filter over the lens, but if the problem IS the exposure then this would
not stop down the light enough during the day to help.

[Solorize]

I reinstalled the Hue DH webcam drivers again lastnight and after disabling the system tray program from loading
and stopping and starting both instances of Yawcam multiple times I managed to get both cameras displaying theirs feeds.
So I tryed changing the resolution on the HUE HD and managed to get it to display 640x480 (with the drivers loaded I could
select many more resolutions). Happy that I finally managed to get it working I decided to reboot my machine to make sure
it all was set up ok. But when it started again only my MS Life cam was displaying... So I decided to uninstall the drivers
again and spent another while of trial and error until I had the HUE HD back to 320X240 and the MS Lifecam both displaying.

So it looks like I can only get the higher resolution when the drivers are loaded, but when they are loaded it messes up the
other webcam..

Anyway now I have the Hue cam feed working, I positioned it to look out of the window, and after looking at it again online
today it has whited-out again. on the HUE HD cam website it does state that the webcam has Auto Exposure Control see below;

http://www.rm.com/shops/thebasement/Pro ... =PD2213472

Features:

Snapshot button
360° rotation
10x zoom
Background effects
Lens effects

Digital noise reduction
Auto exposure control
Auto white balance
Brightness control
Contrast control


But it does not seem to be doing anything to adjust to the light conditions.

My only thought is that without the drivers loaded it does not use this feature.

So my next plan is to install it on my laptop along with the drivers and set that up to look
out of the window and see if it exposes correctly. Luckily it's the weekend tomorrow so I can
test it while its daylight.

If it does work then I may have to reside to having it permenently set up on my laptop and have
it FTP upload from there, as well as having the MS lifecam on my server.

Obvioulsy with all the electricty prices that have gone up recently I would rather have only one
machine running 24/7 than both.