[mythtv-users] Mythbackend problem as daemon?

[Andrew Hogue]

Hi,

Yup, Redhat it is...

I changed the console.perms file to have 666 permisions on the v4l
files and that solved the problem!  I can now watch TV right after reboot!

I've noticed that Redhat likes to change the permissions of most /dev/*
files to be 600 in the console.perms file...

Thanks again!

-- Andrew



On Tue, 7 Oct 2003, Jarod C. Wilson wrote:

> On Tuesday, Oct 7, 2003, at 16:45 US/Pacific, Andrew Hogue wrote:
>
> > Hi,
> >
> > I'm experiencing a funny little problem.
> >
> > When I reboot my computer and then log in and start mythfrontend, I am
> > unable to watch TV.  I see a blue screen, I get audio but no video.
> >
> > However, I did notice that when I didn't run mythbackend as a daemon at
> > startup but ran it as a process just before I started mythfrontend, I
> > could watch TV perfectly fine.
> >
> > It seems that starting mythbackend in the startup process isn't working
> > properly.
> >
> > Any ideas?
>
> Yep. Red Hat by chance? And attempting to run the backend via init
> script as the user you're logging in as? Due to the way Red Hat assigns
> permissions to /dev entries, you have to launch the init script as root.
>
> The long and short of it is that Red Hat assigns the logged in user as
> the owner of many /dev entries, including the key one here, /dev/video0
> (or what have you). The group is always root, and prior to anyone
> logging in, the owner is also root. So if you start up the backend
> before logging in (like with an init script), the permissions on
> /dev/video0 are such that the user you're trying to launch the backend
> as doesn't have permission to use /dev/video0, and things go awry.
>
> Using the init script while logged in as that same user you're trying
> to run the backend as, the permissions are correct, so things work. To
> the best of my knowledge, you either have to change the permissions on
> /dev/video0 to world-read/write or launch the backend as root (I launch
> it as root, and have never had a problem with it).
>
> If you're running something other than Red Hat, I'm not sure what, if
> any of this, would apply. But it sounds like it is an issue of
> permissions on /dev/video0 to me.
>
> --Jarod
>
> --
> Jarod C. Wilson, RHCE
>
> Got a question? Read this first...
>      http://catb.org/~esr/faqs/smart-questions.html
> MythTV, Red Hat Linux 9 & ATrpms documentation:
>      http://pvrhw.goldfish.org/tiki-page.php?pageName=rh9pvr250
> MythTV Searchable Mailing List Archive
>      http://www.gossamer-threads.com/archive/MythTV_C2/
>
>