USB and Webcam Tests

Webcam Test Programs

luvcview and guvcview are display programs that can be used to test a webcam. uvccapture will save an image to the current directory. Each were installed with Synaptic. For example to run guvcview:

eepp@tabor:~/Pictures$ guvcview
guvcview 1.1.3
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
bt_audio_service_open: connect() failed: Connection refused (111)
video device: /dev/video0 
/dev/video0 - device 1
Init. UVC Camera (046d:0805) (location: usb-0000:00:1d.7-1)
{ pixelformat = 'YUYV', description = 'YUV 4:2:2 (YUYV)' }
{ discrete: width = 640, height = 480 }
	Time interval between frame: 1/30, 1/25, 1/20, 1/15, 1/10, 1/5, 
...

An example of a window that it opens is:

Trouble Shooting USB

Us lsusb from usbutils. You can check installation with Synaptic. For example:

eepp@tabor:~$ lsusb
Bus 004 Device 006: ID 04fe:0006 PFU, Ltd 
Bus 004 Device 005: ID 04fe:0008 PFU, Ltd 
Bus 004 Device 003: ID 03eb:21fe Atmel Corp. 
Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 003 Device 003: ID 05ac:0304 Apple, Inc. Optical USB Mouse [Mitsumi]
Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Bus 001 Device 010: ID 046d:0805 Logitech, Inc. 
Bus 001 Device 007: ID 06c2:0059 Phidgets Inc. (formerly GLAB) 
Bus 001 Device 006: ID 06c2:0045 Phidgets Inc. (formerly GLAB) PhidgetInterface Kit 8-8-8
Bus 001 Device 002: ID 05e3:0608 Genesys Logic, Inc. USB-2.0 4-Port HUB
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

For example the following will give you a lot of information about the Logitech webcam on bus 1 device 10.

eepp@tabor:~$ lsusb -s 1:10 -v
bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass          239 Miscellaneous Device
  bDeviceSubClass         2 ?
  bDeviceProtocol         1 Interface Association
  bMaxPacketSize0        64
  idVendor           0x046d Logitech, Inc.
  idProduct          0x0805 
...

Trouble Shooting Webcams

After plugging in the webcam, make sure its driver has been activated. Make sure the /dev/video0 is there:

eepp@tabor:~$ ls -l /dev/video0 
crw-rw----+ 1 root video 81, 0 2012-05-12 09:44 /dev/video0

As root you can force this with

mknod /dev/video0 c 81 0

Also

eepp@tabor:~$ lsmod | grep uvcvideo
uvcvideo               57438  0 
videodev               34457  1 uvcvideo
v4l1_compat            13251  2 uvcvideo,videodev

If not, as root do a

insmod /lib/modules/2.6.32-38-generic/kernel/drivers/media/video/uvc/uvcvideo.ko

The version numbers depend on Linux version installed.