Setting up a MythTV system based on Mythbuntu

Introduction

This document records the steps that the Blackpool Linux User Group took to get a MythTV system up and working.

Goals of our MythTV machine:

To provide a usable EPG (electronic program guide) for upcoming programmes To schedule and record Freeview programmes directly or via the EPG To play DVD’s (and retrieve info from online sources, e.g. IMDB) To play video files (formats?) Note: Playing music and viewing images is not a priority for the group (and MythTV is notably weak in this area).

MythTV Software

Mythbuntu (Download from http://www.mythbuntu.org/) is a distribution of MythTV built on Xubuntu, with many pre-configured customisations that has its own application specifically for managing the configuration of the hardware, software and associated data such as the EPG and remotes

Why we choose Mythbuntu

We are all familiar with Ubuntu to a greater or lesser degree The Mythbuntu ‘distro’ is mature, officially supported by Canonical, is hardware-savvy and takes away many of the frustrations around getting MythTV working

Specifications of the machine

TBA (actual/minimum/recommended) 
DVD Burner
Special considerations, Noise and power consumption. 
Specific MythTV hardware needed:

Digital TV card(s) Here you will find a list of compatible cards:

A TV aerial or a satellite dish, an old sky minidish will be perfectly OK.
Wireless controller (we used a Microsoft-branded media centre remote) http://www.mythtv.org/wiki/LIRC
Speakers are a good idea! http://www.mythtv.org/wiki/Sound_card

Installing Mythbuntu

Insert the disk and follow the on-screen instructions (this first part was almost too easy – see Problems)
Note: We took over the whole disk as part of the installation. Initially the process failed at the point in the installation where GRUB is installed. We eventually resolved this by replacing the hard drive.
The official mythtv guide is here:- http://www.mythtv.org/docs/

Configuring Mythbuntu

(not sure what was done here? It just seemed to work straightaway, though we haven’t configured any tuner cards yet)
Configuring the media centre remote
Exited the MythTV frontend application – drops back to Xubuntu desktop Ran the Control Centre application which can be found in the Multimedia section on the Applications menu Ran the remote mapping scripts by selecting our specific model in the Control Centre application. Quit this and went back into MythTV frontend So far this appears to work just fine without additional tweaking. Here you can find a list of supported infrared receivers: http://www.lirc.org/html/table.html

Configuring MythTV

MythTV consists of a backend process and a frontend process. The backend must be configured using mythtv-setup,which can be found on the Mythbuntu settings menu (menu name to be confirmed). The mythtv-setup program offers to stop the backend process as most changes will not be used until the process is started again.

General

The first option to be configured is named General here you can setup the IP address of the backend server. If you only intend to have one computer running both the backend and the frontend process then you can leave the defaults values as localhost (127.0.0.1). If you intend to have other mythfrontend clients then you will need to enter the IP address or the name of the backend server.

Capture cards

The next option which needs to be configured is the Capture Cards. Here you can tell the system how it is going to receive the television signals, there are many different types of capture card which can be used but we are currently going to use the DVB DTV option this is the correct option for both PCI and USB devices.

Video Sources

This option is used to group your capture cards together, even if you have just one capture card you have to create an entry here. Each group should contain cards which provide the same channels, so you would have one group for Freeview and one for Freesat and another for SKY. We will just create one group and name it Freeview.
Input Connections
This option allows you to link you capture cards to the Video sources group you have just created.
Channel Editor
Once everything else has been configured above you can then use this configuration to add channels, if you are using digital capture cards as we are you can just use the channel scan button to scan for and add the available channels.
Storage Directories
This configuration allows you set various locations for the storage of different files. Each storage type can have multiple physical storage locations and in this case MythTV will search each location for the required files. So if you run out of space for your recordings you can add another drive without having to move your existing recordings. MythTV will the just use the disk with the most amount of free space (depending on other settings).
Other things to look at (once the main box is working)
Using MythTV as a UPNP/DNLA media server for other devices, e.g. media players, pc, XBOX, phones, etc.
Using SFF/embedded hardware, e.g. Revo, eeePC, etc to build a small combined front-end/back-end system Using MythArchive to export recordings to DVDs and other media. Usage
The official MythTV wiki has an excellent user manual which you can find here:
These instructions are for version 0.24 of MythTV, the version we are using at the moment is 0.23-fixes but the daily usage has not changed very much.

Problems

On Saturday we had some difficulty getting the Avermedia PCI DVB-T card working with Mythbuntu 10.04.
I took it home and built a Mythbuntu 10.04 system and put this card in, I also had the same problem i.e. i could not scan for channels.

Looking in the messages log

(tail -f /var/log/messages) I could see that the system could not find or load the firmware for this card. After some research I found that we were not the only people who have difficulties with this card, but there is a solution. Apparently the system incorrectly identifies the card at startup and tries to load the wrong firmware which fails and makes the card unusable.
The solution to this is to update the kernel within 10.04 this is done by just asking the package manager to update the kernel and then rebooting. Once this is done the system will correctly identify the card.
Next we have to download and install the firmware for this card, this can be done by installing the Ubuntu firmware package using the package manager the package is named linux-firmware-nonfree.
This appears to work and allows you to configure MythTV and scan for channels, when I performed the scan at home I found 41 TV channels and the 5 I tested all were watchable even though the BBC channels were picked up from the transmitter in Wales instead of Winter hill.
After rebooting the computer I found another problem when using this card with Mythbuntu, the myhthbackend process is configured to startup before the system has finished configuring the hardware. The loading of the firmware takes time and the card is not ready until this is finished.
The solution to this is modify /etc/init/mythtv-backend.conf as follows:
Replace line
start on (local-filesystems and net-device-up IFACE=lo) with
start on (local-filesystems and net-device-up IFACE=lo and started udev-finish) This makes the startup process a bit longer but it does make sure the hardware is ready.

More Problems

After making these changes we found that we could still not scan for channels. So to fix this we had to use the backend setup program to delete all of the configured capture cards. The next step was to use the backend configuration program to add the capture card again. Now the channel scan found lots of channels but it was missing the BBC channels. We did not try to resolve this, but a good start would be to use the command line scan utilities to check which channels can be found.
dvbscan dvb-t/uk-Winter Hill > channels.conf
or
scan dvb-t/uk-Winter Hill > channels.conf
these utilities are not provided by MythTV they come with the DVB utilities, the uk-Winter Hill command line value is a file that is installed with these utilities and provides the details of this transmitter. 
This page herehttp://www.ukfree.tv/txdetail.php?a=SD660144 provides technical details of the Freeview transmissions from Winter Hill, so if you are missing one group of channels you can work out which multiplex/frequency you are missing. MythTV allows you to enter the details manually and the perform a quicker scan so that you can get just the channels you are missing. If you do look at this site you will notice that there are 4 HD channels on multiplex PSB3 you we can not receive these as to do so you will need a DVB-T2 card.
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