[mythtv-users] Mythcommflag is off by one

Jon Boehm boehm100 at comcast.net
Wed Sep 26 18:42:34 UTC 2007

Chris Pinkham wrote:
> * On Mon Sep 24, 2007 at 06:07:37PM -0500, Craig Huff wrote:
>> Don't think I have run transcode.  Yet. ;-)
>> So, how would you recommend fixing them?
> You'd want this:
> ionice -n 7 nice -n 20 mythcommflag -j %JOBID% -V %VERBOSELEVEL%
> That would run the normal JobQueue's normal mythcommflag
> command with the preceeding nice and ionice.  The JobQueue will
> already nice jobs if you set the JobQueue CPU usage setting to
> LOW, and mythcommflag will go a step beyond that and will sleep a
> little every frame when set to this LOW value, so your "nice"
> isn't really required.  The JobQueue does use a nice(17) though,
> so your 20 is a little better but unless you set the CPU usage
> setting to LOW, mythcommflag will still run full-bore when it can.
> People with software encoders have seen issues even when running
> niced, so when set to LOW, the flagger will sleep a little between
> each frame to be extra-nice. :)


Thanks for this explanation.  I found it very helpful.  I've always 
wondered why one mythcommflag job only take 25% of the cpu when NOTHING 
else is happening on the system.  I plan on changing my JobQueueCPU from 
(0, LOW) to (1, MEDIUM) or (2, HIGH), since I don't have software 
encoders in order to get rid of the pause between each frame.

One question though, doesn't the mythbackend job need to be run as root 
for the ionice and nice commands to execute in this fashion? Unless you 
edited your /etc/sudoers file to allow ionice and nice for your 
mythbackend user.  Do I have this incorrect?


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