20090131

Installing Mythbuntu

The K45 doesn't have a slot for a CD drive, so I decided to install from a USB drive (my MP3 player).

I downloaded the Mythbuntu 8.10 x86 ISO, and tried to use usb-creator to write it to the MP3 player. Nothing happened. The program just hung.
I gave up on usb-creator and used UNetbootin instead. This worked first time and didn't delete my MP3s.

The K45 booted from the MP3 player and X11 appeared on the TV.
The resolution was the TV's native 1360x768 with a 60Hz refresh rate, but the display was shifted to the right so I can't see the clock. The controls on the TV are unable to correct this.
The picture is also slightly wobbly. These problems disappear when the resolution is changed to 1024x768.

I ran the installer, it partitioned the hard drive with a small ext3 / partition and the rest as an xfs /var.

The installer asked for mysql and mythweb passwords, but these were ignored.

Mythbuntu automatically logs in as the user that was created during install and mythfrontend is started. No keyboard or mouse are required.

I used NetworkManager to connect to my wireless network. It asked for a password to secure the
keyring with. In normal Ubuntu, you should use the same password as your user account, so that the keyring can be unlocked automatically when logging in. As Mythbuntu logs in automatically without a password, it doesn't know the password to use to unlock the keyring. So when setting the password for the keyring you need to use an empty password.

A PC uses more power than a set-top box, so it's a good idea to turn it off when not using it. But the PC needs to be on to record a scheduled programme, so an alarm has to be set to turn the computer back on a few minutes before the recording. The alarm is set by writing the required time to /sys/class/rtc/rtc0/wakealarm. Mythbackend can be configured to automatically set the alarm and turn the computer off when it is idle and there are no clients connected. There is a problem here - mythfrontend is started every boot, so there will always be a client connected, and the computer will not be turned off. The solution is to start mythwelcome instead of mythfrontend. Mythwelcome can start mythfrontend when requested using a remote control. To start mythwelcome at boot edit /etc/mythtv/session-settings and set MYTHWELCOME=true.

Now that the PC isn't on all the time, cron processes do not run, so the weekly database backup doesn't happen. To fix this, just install the anacron package.

The driver for the remote control I use converts the IR signals into key presses.
The keyboard controls for MythTV can be configured.
So you'd think that it should be possible to configure MythTV to use the key presses from the remote, without having to go through LIRC. It isn't, I'm not sure if this is a bug in MythTV or in the QT library it uses.

When using the arrow keys on my remote, I noticed that the key presses were being duplicated.
It turned out that the IR sensors on both DVB tuners were receiving and understanding the signals.

In Mythbuntu 8.10, HAL automatically configures the X11 server with all connected keyboards.
This includes the remote controls, so LIRC is unable to get exclusive access to the remote control. This bug has been fixed by creating a HAL configuration file to tell it to ignore
some keyboards that are known to be remote controls. This also allows me to ignore the IR sensor on one of the tuners.

When Mythbuntu installs LIRC, it automatically creates the LIRC configuration files for MythTV, Mplayer, Vlc and Xine that are tailored for the remote control you're using. These are a useful starting point, but I've had to tweak them.

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