2

I have a Logitech C920 webcam connected to my computer running Debian Linux. I want to access the stream by using mplayer (/dev/video0) and it works out of the box. However, the saturation/brightness/other settings are not correct, so I use guvcview to set the proper configuration.

If I keep the preview window from guvcview open, I can't connect to the stream anymore because the device is busy (= in use by guvcview). mplayer returns an error. If I close guvcview my settings are gone and the stream is 640x480 again (instead of 1280x720). I get the same error when using openCV to connect to the stream:

  • without guvcview: connected, but bad settings
  • with guvcview running: good settings, but can't connect to /dev/video from any other programs (blocked by guvcview)

Here are some parts of the console output when setting the configuration in guvcview. I don't know if its helpful:

V4L2_CORE: Unable to find parent usb device.V4L2_CORE: Unable to find
parent usb device.GUVCVIEW: version 2.0.4
V4L2_CORE: (UVCIOC_CTRL_MAP) Error: Inappropriate ioctl for device
V4L2_CORE: failed to subscribe events for control 0x00980001:
Inappropriate ioctl for device
V4L2_CORE: failed to subscribe events for control 0x0098f900:
Inappropriate ioctl for device
Cannot connect to server socket err = No such file or directory
Cannot connect to server request channel
jack server is not running or cannot be started
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for
4294967295, skipping unlock
JackShmReadWritePtr::~JackShmReadWritePtr - Init not done for
4294967295, skipping unlock

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.