[mythtv-users] Permission problem on /dev/video 0-3

Greg greg12866 at nycap.rr.com
Thu Jul 29 13:55:11 UTC 2010

On 07/29/2010 09:21 AM, bhaskins wrote:
> MacNean Tyrrell wrote:
>> Ok so my fathers mythtv box running .23, 2  days ago was running 
>> fine.  Tonite he calls me and says mythtv isn't recording.  I go up, 
>> information says recorders has an error.  I look in the mythtvbackend 
>> log, i see:
>> Channel(/dev/video0)::Open(): Can't open video device, error 
>> "Permission denied"
>> Channel(/dev/video1)::Open(): Can't open video device, error 
>> "Permission denied"
>> Channel(/dev/video2)::Open(): Can't open video device, error 
>> "Permission denied"
>> Channel(/dev/video3)::Open(): Can't open video device, error 
>> "Permission denied"
>> I did some searching and say and error with pvr150's and a udev 
>> fixing it.  However, both of his are pvr500's.  I did try that fix 
>> but it didn't work.  The weird thing is, once X is loaded, if I ssh 
>> in and run:
>> sudo service mythtv-backend restart
>> Everything works fine.
>> He hasn't done updates (he doesn't without me) in those 2 days.
>> The permisions on /dev/video0-3 is
>> crw-rw----- root video
>> where video has mythtv/hisusername as part of the group.
>> The udev rules made it:
>> crw-rw-rw- root video
>> But again non of this fixes mythbackend running correctly on bootup. 
>>  I have to VNC/SSH in and restart the backend, but once I do it works 
>> fine.
>> So if anyone could shed some light on this for me that would be 
>> great.  I do have autobuilds for mythbuntu enabled, I believe he's 
>> running 25368.  Please help me out here.
>> -- 
>> Sincerely,
>> MacNean C. Tyrrell
>> ------------------------------------------------------------------------
>> I think that we are seeing the same problem showing up in different 
>> ways.
> I had this hit on several different ways, and it did come from one of 
> the ub10.4 updates.
> The first sign was that mythweb shows blank pages, after that other 
> problems will
> sneak out under the baseboards.
> It appears to be a sequencing problem, the backend  starts before it 
> should.
> The workaround is to restart the backend.
> On one box I just gave up and went back to 9.10 ( works fine again ) 
> but this also had
> ongoing problems with hibernation crash and major wireless problems.
> Ub10.4 has just not worked well for me, I hope that they can fix it in 
> 10.10.
> Does anyone see any advantages to upstart?
>> _______________________________________________
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I don't see any advantage,but it seems Ubuntu and all the major distro's 
must change things just for the sake of changing things...
I don't use upstart for starting my backend, I put mythbackend in 
startup applications..It works for me ..It might not be the most elegant 
solution,but  who can argue with success... One other pet peeve of mine 
is pulse-audio..Why not make that an option for those people  who don't 
want or need it???
  It seems to me they are trying to gain users by making Linux look and 
act like Windows...

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