A few Myth TV tips for Ubuntu 12.04

Good morning all!

I've been using MythTV 0.25 on Ubuntu 12.04 for a little over a month now, and while pleased overall, there were a few annoyances that caused me to scour the Interwebs for a solution. Things are working better now, so I wanted to share my tips for others out there!

1) Legacy Full Screen Support

If you are using Ubuntu with Unity, you may notice the MythTV interface doesn't completely go "full screen". That is, it's somewhat shadowed by the Unity bar and top bar.

To fix this, you'll need the CompizConfig Settings Manager. I don't think this is installed by default, so find it in the Ubuntu Software Center. Note that this is an advanced tool to mess with your settings, and while there is some pretty cool stuff in here, do be careful.

To get MythTV full screen over the Ubuntu panels, use "Legacy Full Screen" support.

1) Under CompizConfig Settings Manager, go to "Utility"
2) Go to "Work arounds"
3) Check "Legacy Full Screen" support.

After that, your MythTV should go properly full screen. Restart if necessary.

Reference: http://www.thegoss.com.au/content/ubuntu-1204-precise-pangolin-mythtv

2) Mythfilldatabase takes forever to run

(Note: These seems to have been fixed in a recent version of mythfilldatabase. A fresh MythTV install on Ubuntu 12.04 seems to no longer have this issue, but the instructions are still here for reference).

One bizarre thing I noticed is that mythfilldatabase never seems to end (actually, my girlfriend pointed out that hard drive was clicking loudly causing me to investigate and finding mythfilldatabase and mysql hogging the I/O. Hint: iotop is a cool program).

This is apparently due to a mythfilldatabase bug, and is fixed in the newest builds, but if you need a work around, here it is:

1) Set up a TMPFS for /tmp
Add the following to '/etc/fstab':

tmpfs   /tmp   tmpfs   nodev,nosuid    0 0

2) Change MYSQL configuration parameter:

Add the following to '/etc/mysql/conf.d/mythtv.cn':

default_storage_engine=MyISAM

Note: It's important to know that in step 1, you are actually switching your /tmp to a TMPFS file system. This means that any data written to /tmp is written to your RAM, and not to your hard disk as usual.

This can have both positive and negative consequences.

Using a tmpfs for /tmp can have some all around nice performance improvements since writing to RAM is far faster than writing to disc. Therefore, programs using /tmp will have their write operations quicker, therefore improving performance.

The downside is that the side of /tmp will be limited to the size of available RAM. This can be issue if /tmp ever becomes full, writes will fail. So, if you run into this issue, your programs may stop working.

If this becomes a recurring problem, you might need to revert your /tmp back to the HD and use the bug fixed version of mythfilldatabase. But, I've been using /tmp as a tmpfs for a good month now and have had no ill effects with moderate usage (I also have 6GB of RAM...just saying.)

Tip: Keep track of /tmp usage with the df command on the command line. Mine is currently only at 1% full.

References:
http://ubuntuforums.org/showthread.php?t=1991684
http://ubuntuforums.org/showpost.php?p=11918589&postcount=35

3) Mythweb PHP errors

I noticed some unusual errors in Mythweb. Simple functions like setting up recordings didn't seem to take, and there were some php error message along the top of some of the pages. This was a bit irritating to fix.

Rather than repeat everything I did, I'll just point you to the official ticket:
http://code.mythtv.org/trac/ticket/10142

I just manually clicked on the individual *.patch files and applied the changes by hand. There's probably a better way to do it, but that worked for me. Hope you find it useful.

4) A new Remove_Commercials script

My first attempt to use my old remove_commercials script failed miserably. Not surprising, since some of the command line parameters changed between versions. But, there's an updated one you can use here:

http://www.mythtv.org/wiki/Script_-_RemoveCommercials 

The script didn't quite work out of the box for me. A few tweaks I made:

1) Replacing all of the usages of $START with "$START"
2) Adding --user=mythtv --password=PASSWORD (where PASSWORD is your mysql password, from the mythbackend settings) to the mysql command
3) You might also get better results if you use -f on mythcommflag instead of --chanid and --starttime, but if they work for you then great.

I'm still playing with the commercial cut script a bit, so I may make some more updates, but hopefully that'll give you something to start with.




One issue I still have is the display mythfrontend runs on. I haven't yet been able to control what display it opens on from the command line as setting $DISPLAY has no effect. But I'll keep trying!

If you have any of your own tips, let us know. Take care, and have a great day!