I'm trying to capture several webcams at the same time. Unfortunately, it's a lot harder than I thought

So, to give more methodology to my varying successes, I made a test for my four webcams and QuickTime (i.e. built-in Processing Capture), OpenCV, JMyron and GSVideo.
Since it looks like it isn't trivial, I thought I'd publish my findings here, although the results may of course be very different when using other webcams.

The webcams are:

• Internal webcam of the Acer TravelMate 4230
• Logitech QuickCam for Notebooks Deluxe
• Logitech C210
• Logitech QuickCam Express
  
• Microsoft Lifecam VX-700

I used the most simple example from every framework. Every example was started with 320x240 and 640x480 resolution, and every example was started as applet or full-screen application. Note that I didn't start these examples from the Processing PDE, but from Eclipse, since it's my preferred IDE (but I don't think it matters anyway).

So, here are the results:

QuickTime

Acer TravelMate 4230 Webcam

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam for Notebooks Deluxe
In general, the Quickcam options window always pops up

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech C210

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam Express

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok
  

Microsoft Lifecam VX-700
In general, the color resolution is bad

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

OpenCV

Acer TravelMate 4230 Webcam
Doesn't work, shows only back pixels

Logitech QuickCam for Notebooks Deluxe
In general, the Quickcam options window always pops up

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech C210

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam Express

• Applet: Crash after closing
  
• Application: ok
• 320x240: ok
• 640x480: ok
  

Microsoft Lifecam VX-700

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

The Logitech QuickCam Express crashes with this error:

1. #
   # A fatal error has been detected by the Java Runtime Environment:
   #
   #  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x7f842adf, pid=2504, tid=532
   #
   # JRE version: 6.0_26-b03
   # Java VM: Java HotSpot(TM) Client VM (20.1-b02 mixed mode, sharing windows-x86 )
   # Problematic frame:
   # C  [lvcodec2.dll+0x2adf]
   #
   # An error report file with more information is saved as:
   # M:\workspace\Tests\bin\hs_err_pid2504.log
   #
   # If you would like to submit a bug report, please visit:
   #   http://java.sun.com/webapps/bugreport/crash.jsp
   #
   

JMyron

Acer TravelMate 4230 Webcam

• Applet: Crash after closing
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam for Notebooks Deluxe
In general, the Quickcam options window always pops up

• Applet: Crash after closing
• Application: ok
• 320x240: ok
• 640x480: Image is repeated three times with black lines

Logitech C210

• Applet: Crash after closing
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam Express
In general, only shows five distorted interlaced black & white pictures, can't be used.


Microsoft Lifecam VX-700

• Applet: Crash after closing
• Application: ok
• 320x240: ok
• 640x480: ok

In general, JMyron crashes after starting a webcam capture in an applet:

1. #
   # A fatal error has been detected by the Java Runtime Environment:
   #
   #  EXCEPTION_ACCESS_VIOLATION (0xc0000005) at pc=0x10001bf0, pid=796, tid=3496
   #
   # JRE version: 6.0_26-b03
   # Java VM: Java HotSpot(TM) Client VM (20.1-b02 mixed mode, sharing windows-x86 )
   # Problematic frame:
   # C  [JMyron.dll+0x1bf0]
   

GSVideo

Acer TravelMate 4230 Webcam

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

Logitech QuickCam for Notebooks Deluxe
Doesn't work: NullPointerException in GSCapture.getSuppResAndFpsList()

Logitech C210
Doesn't work: NullPointerException in GSCapture.getSuppResAndFpsList()
 
Logitech QuickCam Express
  Doesn't work: NullPointerException in GSCapture.getSuppResAndFpsList()


Microsoft Lifecam VX-700

• Applet: ok
• Application: ok
• 320x240: ok
• 640x480: ok

So, I think that this can help someone else. If anything, I think that it shows it's difficult to work with webcams 

Best regards,
Eric

P.S. Next step will be to combine several webcams and to test what works with what combination.