[mythtv-users] correctly setting permission for /dev/video* ubuntu 12.04+myth
Michael T. Dean
mtdean at thirdcontact.com
Thu Jun 14 13:53:58 UTC 2012
On 06/14/2012 09:08 AM, Allan Strand wrote:
> Hi All,
>
> Ubuntu 12.04 and MythTV 0.25.1
>
> I have a hdpvr that works fine with the exception of color balance.
> As documented multiple places, the device can be controlled with
> 'v4l2-ctl' and this issue can be fixed.
>
> So I have a bash script to change the settings using this approach
> that's called by my channel change script.
>
> Unfortunately, the script does not seem to run when channel changing,
> though it does when I run from command line.
>
> I suspect this is a permission problem, so I added mythtv (the user
> that runs the backend) to the video group on this machine and verified
> that group permissions on /dev/video1 (pvr-150 on video0) allow both
> reading and writing.
>
> Still there seems to be no change to the device. Also, I'm not sure
> where to find stderr output from the channel change script. It does
> not seem to appear in the mythbackend log.
>
> Any pointers to solutions to what must be a common problem?
Perhaps you're running it too early--before MythTV sets it device
settings? Try putting a sleep in the channel change script before the
color-fix script is run.
Also, I think there's a fix for the "wrong colors with new HD-PVR
firmware versions" available (in new kernels or something?). Might want
to just fix the issue, instead of working around it.
Mike
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