How to permanently set higher process priority in GUI

[Nils Kassube]

Tony Baechler - BATS wrote:
> I'm having a bit of a problem.  When transcoding video from .mpg to
> other formats like .mp4, it's really slow.  On the server, the
> process takes maybe a minute or two, but on the desktop, even after
> several minutes, it wasn't done and it's only a 7 minute video.

Maybe you should measure the time it takes to transcode the video and 
not just guess from memory. After all I wouldn't say there is a big 
difference between "two minutes" and "several minutes". And make sure 
you are transcoding with the same input files and identical conversion 
parameters.

> This
> is with ffmpeg.  I was thinking perhaps the problem has to do with
> ffmpeg not getting a high enough priority.  On the server, it does
> not have X and everything is done from the command line, so I can
> simply run "nice -19 ffmpeg $@" and it works. However, with the
> desktop, that isn't really possible because the user has no command
> line knowledge and obviously doesn't want to go into Terminal every
> time.
> 
> Both the server and desktop are running Ubuntu 14.04 with the Trusty
> multimedia repository added.  We have tried handbrake, winff and
> another GUI frontend.  I personally don't use the GUI and I'm of
> little help here, but I think winff is the best option because it
> uses ffmpeg, but I'm not positive on this.  We are using the real
> ffmpeg with all extra and nonfree codecs, not libav-tools which is
> the default.  The desktop has at least 4 GB of RAM, two cores and is
> running Xubuntu.

I don't think you can gain anything noticeable if you increase the 
priority. Just for fun I did an experiment. I transcoded a 15 min. video 
from mpg to mp4 using avconv on my dual core 1.8 GHz machine. With the 
command 

avconv -i filename.mpg filename.mp4

the job was finished after 17:26. Using the same input file with the 
command

sudo nice --19 avconv -i filename.mpg filename.mp4

the job was finished after 17:28, so there was virtually no difference.

I would expect that the main problem was that the desktop user had other 
applications running at the same time which needed a lot of resources, 
not only X alone. Something like firefox running with a lot of tabs for 
various websites.


Nils