Mythbuntu

Mythbuntu is a media center linux distribution which combines an operating system (ubuntu) with software (mythtv) to achieve a complete DVR and video library system. Mythbuntu is an official Ubuntu flavor focused upon setting up a standalone MythTV based PVR system. Mythbuntu is a custom Ubuntu distribution with a prebuilt MythTV install, and it is a Ubuntu that has been optimized for use with MythTV.

Ubuntu is a linux distribution that typically uses Gnome Windows Manager. Mythbuntu does not use Gnome. Mythbuntu uses Xfce as the Window Manager.

MythTV is a software that runs on Linux to virtually turn a Linux desktop system into a DVR. MythTV can run entirely on a single system, or utilize a front-end back-end configuration.

MythTV is "beta" quality DVR software for a PC running Linux. Even under the most standard, typical hardware configurations Mythbuntu and MythTV work reasonably well but not without errors and annoyances. The use of the term "beta" is opinion rather than an official designation by the developers (-2014).

Typical Problems with Mythbuntu

HDMI audio does not work by default
pulseaudio server will not start
smb/cifs not included by default
unexplained crashes
scheduled recording fails when tuner on LiveTV
storage group design makes alternate video player fail
screen goes black

See the Section: Mythbuntu#Troubleshooting

unexplained crashes

While watching LiveTV, or while watching a recording which may be associated with a tuner active in recording another program at the time, popup crash messages appear. Messages are infrequent, however, seemingly random and very annoying.

The Cancel button is clicked. Playback of a recorded program continues, even during the error popup. The popup blocks part of the viewable screen space. Once the popup goes away, a new popup appears.

Send an error report? Sounds like Microsoft! Click "Show Details" and lets find out what went wrong so it can be fixed.

The error report itself has now crashed. Meanwhile the video is still playing behind all these popups. The cause for the error is never determined. The error report will not complete.

This is a fairly common problem with Mythbuntu installations on common PC hardware. Due to the attitude towards bug reports by the MythTV developers, it is unlikely the problem will be addressed in the near future. Fortunately, this tends to be a once-per-day type of error in most cases and like most things with buggy software in our modern age, simply gets tolerated.

RESOLUTION: none.

Customization

Use the The apt-get Package Management Tool to install packages.

Theme Notation

The most common screen resolution of an LCD panel television is 1920x1080 - which is 16:9 . Some themes do not work well on the common television.

Arclight - not recommended.
Steppes - fair. Glitches in media library view.
Mythbuntu 25.30 - excellent.

Key bindings to mimic VLC

I like to have the SPACE BAR pause and resume to mimic the behavior of VLC Player.

Setup, Edit Keys, TV Playback, Pause, and press the SPACEBAR when prompted in the empty slot after the "P."

The key binding conflicts with another which can easily be removed.

Setup, Edit Keys, Global, Select, and select the slot with SPACEBAR to remove the binding. Press ESCAPE and Save Changes.

Paths: File Locations

MythTV DB does not care about the exact path to a recorded program video file. It only cares that the file resides somewhere in the configured root path, and the specific name.

With Mythbuntu, and perhaps most MythTV installs on Linux, media is stored under /var/lib/mythtv unless otherwise configured differently by the user. See these common directory names under /var/lib/mythtv

/var/lib/mythtv/ 
             banners  bare-client  coverart  db_backups  fanart  livetv  music  
             pictures  recordings  screenshots  streaming  trailers  videos

/var/lib/mythtv/livetv - all live TV contact for the current period (typically for the last 24hrs) that has been watched or recorded. Sometimes scheduled recordings fail to show up in the Media Library-Recordings list can be found here too. Names on FS are not meaningful and are associated with MythTV DB entries. SEE: MythTV Offical Wiki: LiveTV

/var/lib/mythtv/recordings - user recorded tv programs. auto configured to share as \\Mythtv\recordings on Windows network. Recorded programming is moved from /livetv to /recordings upon completion of scheduled recording or user initiated recording. So to speak, everything is recorded, that which is marked recorded is moved here.

/var/lib/mythtv/streaming -

MythTV directories that are shared to Windows network neighborhood are done so with Linux CIFS Utils and Samba with the configuration file {smb.conf) being at the path /etc/samba/smb.conf - example: Example Mythbuntu SMB Shares. If you modify smb.conf you will need to restart the service: service smbd restart && service nmbd restart

Menu Structure of Mythbuntu 25.30 Theme MENU

Mythfrontend 0.25 
|
+---Media Library
|   +---Watch Recordings
|   +---Watch Videos
|   +---Listen to Music
|   \---Image Gallery
|
+---Manage Recordings
|   +---Schedule Recordings
|   |   +---Program Guide
|   |   +---Program Finder
|   |   +---Search Words
|   |   +---Search Lists
|   |   \---Custom Record
|   |
|   +---Recording Rules
|   +---Upcoming Recordings
|   +---Previously Recorded
|   \---Set Priorities
|
+---Information Center
|   \---System Status
|
+---Optical Disks
|   +---Play Optical Disc
|   +---Import CD
|   \---Eject Media
|
+---Watch TV
\---Setup
    +---Setup Wizard
    +---General
    +---Appearance
    +---Theme Chooser
    +---Audio
    +---Video
    +---Media Settings
    +---System Event Handlers
    +---Edit Keys
    +---Artwork and Metadata Sources
    \---Screen Setup Wizards

extras

Install vim editor

apt-get install vim

Set VNC password

sudo x11vnc --storepasswd

To connect to windows shares you need cifs

apt-get install cifs-utils

Install Firefox, because Chromium doesn't support NoScript.

apt-get install firefox

Easy way to secure transfer files

apt-get install lrzsz

disable screen blanking

After my computer with ubuntu 12.04 has been idle for a short while, the screen will go blank, and even enter standby mode. Drop out of MythTV frontend to Xfce and on the menu in the upper left:

Applications, Settings, Screensaver

~~Change "Blank After" to 0 or any value you want.~~ Change "Screensaver" to "none."

STATUS: update. TV blanks on MythTV menu. Does not blank on livetv, player, or Xfce desktop. Culprit is a communications issue on the HDMI interface. HDMI technology flaw, implementation flaw, failure for some television and monitor manufacturers to adhere to HDMI specifications. On a Vizio brand display exhibiting the problem changing the automatic luminance to disabled seems to resolve. Keep in mind that pressing a button like "input" on the remote will recover display.

sudo xset dpms 0 0 0 && xset s off && xset s noblank
xset q

xset -dpms
xset s off

Using VLC Player for playback

Using VideoLAN Player for playback in MythTV (otherwise known as VLC Player) for all video files or certain video files.

The subject is covered in the Official MythTV Wiki (MythTV VLC).

The location in the Front End is:

Setup, Media Settings, Video Settings, Player Settings

Note: VLC Player exists without playing video. UNRESOLVED.

The reason is due to the way MythTV uses STORAGE GROUPS for your video files (those not recorded using MythTV). If you have MythTV configured to access a path containing video files (such as a LAN path or NFS path, or even local) the MythTV Frontend sees this in a Storage Group. SG = Storage Group. MythTV will not allow Storage Group content to be played with an external player such as VLC. (Yeah this is a sucky deal and a strike against MythTV.)

For example, /var/lib/mythtv/videos is seen by MythTV and sent to the external player as myth://Videos@localhost, which is a storage group path.

further research and reading

Adding files from a windows share to MythTV media library

There are more than one ways to do this. This example uses cifs to permanently mount the shares so that they will be available after reboot. If the system complains add the 'noauto' parameter.

First edit your /etc/hosts file and add the hostname and IP address of the windows share or file server
Next create mount points in /mnt for each windows share
Make sure you have cifs installed
Edit /etc/fstab and add a line for each windows share, see examples:

//apollo/public/ /mnt/public cifs username=nicolep,password=mythtv,iocharset=utf8,sec=ntlm  0  0
//apollo/media/ /mnt/media cifs username=nicolep,password=mythtv,iocharset=utf8,sec=ntlm  0  0
//apollo/video/ /mnt/video cifs username=nicolep,password=mythtv,iocharset=utf8,sec=ntlm  0  0

mount the shares

mount -a

This provides read-only access to the network shares.

KERNEL CHANGE BREAKS CIFS.

Somewhere between kernel 4.10.0-38 4.15.0-20 a change was made that COULD PREVENT your cifs shares from mounting. Kernels at and before 4.10 used SMB (Server Message Block) version 1.0 as the default if not specified. Most folks did not specify it so it defaulted to 1.0 and worked. Microsoft ditched 1.0 in Windows 10 and dropped support. Linux kernel developers decided to change the kernel code to no longer default to SMB 1.0 and now default to a newer version. For people that are using legacy networks or NAS devices, it breaks the mounting example from above.

Solution: Specify the SMB version.

The solution is to tell mount.cifs to use the SMB2, SMB2.1 or SMB3.0 protocol using the "vers" parameter. in Linux CIFS Utils and Samba Specify 1.0, 2.0, 2.1, or 3.0.

For the following full line example a linux desktop is connecting to an older NAS device. It is necessary to specify SMB version 1.0. Example:

//apollo/video/ /mnt/video cifs defaults,vers=1.0,domain=workgroup,username=nicolep,password=mythtv,iocharset=utf8,sec=ntlm 0 0

See Linux CIFS Utils and Samba for more information on installing cifs-utils and mounting Microsoft Windows shares.

In the MythTV Frontend: Setup, Media Settings, Video Settings, General Settings.

Troubleshooting

For troubleshooting it helps to know your Mythbuntu version

cat /etc/lsb-release

There's sound on line out, but not on HDMI

Manifestations

Audio present in MythTV frontend but not in X.org
Audio absent in MythTV frontend and present in X.org
No Audio in MythTV frontend and X.org

CORRECT IN MYTHTV SOFTWARE

In MythTV this can be corrected easily. From the MythTV Frontend:

Setup
Audio
Change "Audio output device" to "ALSA:dmix:CARD=PCH,DEV=3" (or whatever soundcard and device tag matches your system)

The default here was "PulseAudio:default". When there are problems with PulseAudio, which is common, it is better to specify your soundcard and output device specifically. For our example we had an Intel ACH audio board.

CORRECT IN X11 (X.org) simple

This is a quick fix. Use this solution only if:

You previously had audio in X.org apps, perhaps before a reboot or other event
You already have PulseAudio Control installed "pavucontrol"
You use an HDMI cable for audio and video to a monitor TV

Sometimes users of Mythbuntu drop back into the xfce to run media software, such as VLC. Even though MythTV Frontend has a working audio configuration, the desktop may not. Once configured, users are noticing that Pulse Audio loses its setting after a reboot or other event, and audio for apps in X.org stop working.

Quick Fix: (assuming you have checked cables are not loose)

Simply open pavucontrol and click the configuration tab. If it is correctly set to "Digital Stereo (HDMI) Output" (or whichever you typically use) inwhich it should be working, and has in the past worked, but is now not working, change it to another option, and then change it back to "Digital Stereo (HDMI) Output." This basically "refreshes" or reminds Pulse Audio what output you wish to use. This seems to kick start the audio and get it working again for most people.

If your problem doesn't meet the 3 bullited criteria above or the Quick Fix solution fails, proceed to attempt the thorough troubleshooting that follows...

CORRECT IN X11 (X.org) thorough

If you go to console and type

aplay /usr/share/sounds/alsa/Front_Center.wav

and do not hear anything out of the TV via HDMI, but do hear if you connect speakers or headphones to the line-out jack, try this:

speaker-test -c 2 -r 48000 -D hw:0,3

Again, the test is on a system with Intel ACH audio and the HDMI puts it on hw:0,3 - yours could be on another like hw:0,7. Here is how to find out where yours is, type this:

aplay -l

Here we seen:

card 0: PCH [HDA Intel PCH], device 3: HDMI 0 [HDMI 0]

The card number and device number you need to know. Another test is to:

aplay -D plughw:0,3 /usr/share/sounds/alsa/Front_Center.wav

Substitute plughw:0,3 with the correct values for your card and HDMI based on the output of aplay -l

Install the mixer.

apt-get install pavucontrol

Open mixer

pavucontrol

In the mixer choose the "Output Devices" tab. If you do not see "HDMI / DisplayPort" listed in the dropdown then do the following:

click on the Configuration tab and select "Digital Stereo (HDMI) Output"
Go back to the Output Devices tab and look for "HDMI / DisplayPort"

If at this point you found and selected the HDMI DisplayPort option, and tested audio is working then stop here. Be sure to test within a program such as VLC and not using aplay from console. VLC will use the pulseaudio device you selected in pavucontrol.

If there is still no sound via HDMI, then proceed...

Now we need to edit the pulseaudio configuration file "/etc/pulse/default.pa" and uncomment, and edit a couple lines:

load-module module-alsa-sink
load-module module-alsa-source device=hw:0,3

Set the "device=hw:0,3" to the appropriate values for your card that you discovered though testing above.

Now start or restart pulseaudio

killall pulseaudio
start-pulseaudio-x11

If it starts, then Good! Now you need to open the PulseAudio Volume Control applet in Xfce

Applications, MultiMedia, PulseAudio Volume Control

Now click the drop-down box named "Port" and choose "HDMI/DisplayPort"

Now the default audio is set to the HDMI into your television. Next time you reboot you might have a problem with PulseAudio again. See the troubleshooting below if this is the cause. It basically means you have to remark out those two lines in default.pa and manually start pulseaudio service "start-pulseaudio-x11"

pulseaudio: pa_context_connect() failed: Connection refused

pulseaudio does not start with system boot and you try to manually start it and get:

$ start-pulseaudio-x11
Connection failure: Connection refused
pa_context_connect() failed: Connection refused

The problem may be caused by an error in one of the pulseaudio config files. Those files are located in:

/etc/pulse

In order to get HDMI audio working, two lines that were enabled in default.pa later caused a problem after reboot.

load-module module-alsa-sink
load-module module-alsa-source device=hw:0,3

Those lines were uncommented in order to get HDMI sound working. After a reboot those lines needed commented out once again so that pulseaudio would start.

Why? Who the hell knows? pulseaudio is very buggy.

random screen blanking / goes black

This happens sometimes when I pause live TV, or sometimes when browsing the video library. It has nothing to do with inactivity. Screensaver off, DPMS off, not related to either. Screen goes black, MythTV is temporarily non-responsive on the HDMI display device (LCD TV). No discernible pattern or triggers. I can watch three hours of live TV and everything is fine. Another time the screen going black happens in the first 15 minutes of a show when I pause or try to skip past commercials. Again, no discernible pattern.

I mentioned my recorded buffer was being lost originally but that is my fault as it is happening with my keyboard actions trying to get the display back. I discovered if I connect with VNC viewer I can see the picture there. It is blanking on the HDMI device.

Screen blanking is also caused by the display device going into standby because it misunderstands the video signal. Vizio displays are infamous for this.

Login screen loops unless you login as Guest

I login and there's this black screen where I can only read some text or error (doesn't matter) and then it goes right back to the login screen. The graphical login just keeps coming back after the correct password. Other text consoles work.

Resolved: Lost permissions to /home/username/.XAuthority - it has been taken over by root owner. Go into /home/username and change it back to your ownership. Do this for ALL files in /home/username that were somehow taken over by root.

Backend Configuration

Adding an additional backend

On the backend machine, open the /etc/mysql/my.cnf file

sudo vi /etc/mysql/my.cnf

Comment the line that begins with bind-address by placing a # in front of it.

# bind-address          = 127.0.0.1

Now restart the MySQL server.

sudo service mysql restart

References:

Master Backend Info- Security Key

You will need this set to add additional mythtv frontends to the network.

In the xfce windows interface use the dropdown menu in the upper left "Applications" and choose System, MythTV Backend Setup.
In the MythTV backend setup choose: General, Security PIN (required)

Keywords: mythubuntu mythbuntu myth-ubuntu mythtv myth-tv myth tv television capture pvr dvr linuxpvr linuxdvr