Find the answer to your Linux question:
Results 1 to 6 of 6
When I run apps like mplayer to use my web cam it uses /dev/video#. For reason unknown to me this number changes and is usually either 1 or 0. I ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Linux User
    Join Date
    Mar 2008
    Posts
    287

    Find video device web cam uses


    When I run apps like mplayer to use my web cam it uses /dev/video#. For reason unknown to me this number changes and is usually either 1 or 0. I have looked on the Internet after struggling to find how to know which /dev/video device is used. So far I can only presume I have used the wrong terms to find how to determine which device the web cam is using. Can someone help me?

  2. #2
    Linux Engineer Kloschüssel's Avatar
    Join Date
    Oct 2005
    Location
    Italy
    Posts
    773
    who does provide you with the /dev/video device? usually this is a driver decision and thus it may be configurable once you found out who the driver is.

  3. #3
    Linux User
    Join Date
    Mar 2008
    Posts
    287
    The device /dev/video is found in the directory /dev and is provided in most Linux distros.
    I have no information on how one would manually assign a device to hardware. I believe this is done during booting which I will stay away from with all dispatch.
    There are commands like lsusb, lspci, etc which list modules and hardware. I found cat /proc/asound/cards lists the sound and video cards/hardware but have not found a command which lists devices and cards. I have bt787, v8235, and camera cards but depending (haven't validated this yet) whether the HV7131R is detected or not seems to dictate whether /dev/video0 is used by the camera or if it is /dev/video1. I would like a command or one I can build to show the card vs device assignments.
    Hope this helps.

  4. $spacer_open
    $spacer_close
  5. #4
    Linux Engineer Kloschüssel's Avatar
    Join Date
    Oct 2005
    Location
    Italy
    Posts
    773
    lspci should do all you need?

  6. #5
    Linux Engineer GNU-Fan's Avatar
    Join Date
    Mar 2008
    Posts
    935
    Isn't that determined by the udev daemon?

    You plug in the hardware and udev looks into some config file what dev node to create.
    Debian GNU/Linux -- You know you want it.

  7. #6
    Linux User
    Join Date
    Mar 2008
    Posts
    287

    Find video device web cam

    lspci yields:
    00:00.0 Host bridge: VIA Technologies, Inc. VT8377 [KT400/KT600 AGP] Host Bridge
    00:01.0 PCI bridge: VIA Technologies, Inc. VT8235 PCI Bridge
    00:06.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
    00:06.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)
    00:10.0 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
    00:10.1 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
    00:10.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 80)
    00:10.3 USB Controller: VIA Technologies, Inc. USB 2.0 (rev 82)
    00:11.0 ISA bridge: VIA Technologies, Inc. VT8235 ISA Bridge
    00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
    00:11.5 Multimedia audio controller: VIA Technologies, Inc. VT8233/A/8235/8237 AC97 Audio Controller (rev 50)
    00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 74)
    01:00.0 VGA compatible controller: nVidia Corporation NV17 [GeForce4 MX 440] (rev a3)
    I don't see where video0 or video1 occur?

    Thank U GNU-Fan!! Your comment seems on to it, but on my system the rules in the appropriate directory were all for CDROM (seems strange). I can at least try those terms in a search to see where that leads unless you have more info.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •