video0, udev and permissions

Chestah · 2005-02-08 20:31:01

Hi, I just installed ArchLinux 0.7, and i'm trying to get my tvcard to work. Somebody at the IRC told me to install udev because it works better with 2.6 kernels (i have 2.6.10 installed).

As user i can't start tvtime:

marco@Prometheus>tvtime
Running tvtime 0.9.15.
rtctimer: Cannot open /dev/rtc: Permission denied
rtctimer: Cannot open /dev/misc/rtc: Permission denied

    Enhanced Real Time Clock support in your kernel is necessary for
    smooth video.  We strongly recommend that you load the 'rtc' kernel
    module before starting tvtime, and make sure that your user has
    access to the device file (/dev/rtc or /dev/misc/rtc).  See our
    support page at http://tvtime.net/ for more information.

Reading configuration from /etc/tvtime/tvtime.xml
Reading configuration from /home/marco/.tvtime/tvtime.xml
videoinput: Cannot open capture device /dev/video0: Permission denied

As root i am able to start it without any errors.
Here is the v4l section of my udev.permissions file:

# v4l devices
video*:root:root:0660
radio*:root:root:0660
winradio*:root:root:0660
vtx*:root:root:0660
vbi*:root:root:0660
video/*:root:root:0660
vttuner:root:root:0660
v4l/*:root:root:0660

/dev/video0 is a symlink to /dev/v4l/video0

marco@Prometheus>ls -l /dev/v4l/video0
crw-rw----  1 root root 81, 0 2005-02-08 14:59 /dev/v4l/video0

Thanks in advance.
Marco Louter

phrakture · 2005-02-08 20:34:27

you need to check the permissions on the "rtc" device... either /dev/rtc or /dev/misc/rtc... that's your problem with the first part...

as for the udev permissions... there's two ways to do it - sticking with the way arch does other things (audio and optical groups), I created a "video" group... you can just use "users" if you dont want the hassle (switch video below to users, in that case):

# v4l devices
video*:root:video:0660
radio*:root:video:0660
winradio*:root:video:0660
vtx*:root:video:0660
vbi*:root:video:0660
video/*:root:video:0660
vttuner:root:video:0660
v4l/*:root:video:0660

Chestah · 2005-02-08 20:48:49

i can now start tvtime with 'tvtime -d /dev/v4l/video0', only the rtc devices aren't working yet.
i still get the permissions error on the rtc devices

lucke · 2005-02-08 21:18:56

On my box /dev/misc/rtc belongs to the audio group. Did you add yourself to the audio group?

Snowman · 2005-02-08 21:20:15

Try this:

rtc:root:video:0660 
misc/rtc:root:video:0660

It will give the right permission for the rtc device.

EDIT: If rtc belongs to the audio group, follow lucke's suggestion instead.

phrakture · 2005-02-08 21:27:35

i don't think rtc should be in video or audio groups... it doesn't make logical sense.... i'd put it under root:users

Snowman · 2005-02-08 21:46:32

phrakture wrote:

i don't think rtc should be in video or audio groups... it doesn't make logical sense.... i'd put it under root:users

Yes... I think phrakture is right. I didn't know what rtc was when I posted. I just googled and found that it means Real Time Clock (RTC). Nothing to do with video or audio.

lucke · 2005-02-08 22:03:11

Well, it doesn't make much sense. But that's the way it is in the genuine udev.permissions file.

-edit-

But it's set to 664. So it shouldn't be a problem.

Arch Linux

#1 2005-02-08 20:31:01

video0, udev and permissions

#2 2005-02-08 20:34:27

Re: video0, udev and permissions

#3 2005-02-08 20:48:49

Re: video0, udev and permissions

#4 2005-02-08 21:18:56

Re: video0, udev and permissions

#5 2005-02-08 21:20:15

Re: video0, udev and permissions

#6 2005-02-08 21:27:35

Re: video0, udev and permissions

#7 2005-02-08 21:46:32

Re: video0, udev and permissions

#8 2005-02-08 22:03:11

Re: video0, udev and permissions

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