Difference between revisions of "Frequently Asked Questions"
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The #mythtv-users [[IRC]] channel on irc.freenode.net can be helpful, but please do read all the documentation that you can before asking questions.
The #mythtv-users [[IRC]] channel on irc.freenode.net can be helpful, but please do read all the documentation that you can before asking questions.
Questions can also be asked on
Questions can also be asked on [[Forums|forum]].
== Development ==
== Development ==
Revision as of 08:05, 23 August 2016
(Note that there are many collections of Questions and Answers. Some are linked from the sidebar: Robert Kulagowski's Official FAQ/Install Guide. You might want to check those before adding a question -- or answer -- here.)
- 1 General
- 2 Development
- 3 Versions and database
- 3.1 I'm getting a protocol mismatch. What is wrong?
- 3.2 Can I use Release X or unstable/development X frontend/backend with release Y or unstable/development Y frontend/backend?
- 3.3 How can I go back from unstable/development code to release X?
- 3.4 Do I really need this backend thingie?
- 3.5 Does the backend need to be running all the time?
- 3.6 Well then, what about this MySQL thing?
- 4 Hardware
- 4.1 I can't get <insert component here> working. Help!
- 4.2 I want a low power, quiet computer to use as a frontend. What are my choices?
- 4.3 Can I run MythTV on a virtualized system?
- 4.4 Can I use MythTV without using my cable / satellite company's provided cable box?
- 4.5 Since I need to keep using my Cable/Sat box, how can I control it with MythTV?
- 5 Operating system
- 6 Software
- 6.1 Why is X taking 100% CPU just drawing the frontend menu?
- 6.2 I upgraded X, Y, and Z and now everything is broken. Help!
- 6.3 Do I need to have the X Window System installed on my backend? I don't want it.
- 6.4 Why am I getting QMYSQL3 errors?
- 6.5 Why am I getting QMYSQL3 Unable to connect?
- 6.6 I get a database 145 error. What is it?
- 6.7 Are there any packages for MythTV for my distro?
- 6.8 Do I really need a window manager for a frontend only box?
- 6.9 How can I get DVD menus to work?
- 6.10 How do I remove recordings that no longer exist on disk?
- 6.11 How long does mythfilldatabase take to run? It seems to be stuck in a loop?
- 6.12 The popups in mythweb don't work
- 6.13 How does mythtv determine tuning frequency?
- 7 Setup
- 7.1 What are the types of channels I can record and what type of capture card(s) do I need?
- 7.2 Where do I get my TV guide data outside the US?
- 7.3 How many capture cards do I need?
- 7.4 How much disk space do I need?
- 7.5 Where have the options for the Fast Forward / Rewind jump sizes gone?
- 7.6 MySQL sucks! Can I use a different database?
- 8 Display
- 8.1 What are my options for connecting my computer to my TV?
- 8.2 All my fonts look like they are the wrong sizes, how can I correct this?
- 8.3 Should I use the mailing list to find out where I can download TV shows/Films?
- 8.4 Why can't I see all of my desktop/MythTV screen on my TV?
- 9 Usage
- 9.1 Why aren't my new recordings showing up in Watch Recordings?
- 9.2 How do I import recordings from other sources into Myth?
- 9.3 I have no interest in recording TV but I wish to use Myth as a music/video jukebox. Is this possible?
- 9.4 Can I temporarily keep MythTV from attempting to record my scheduled programs?
- 9.5 Myth won't record a later showing of a program
- 9.6 Myth keeps recording shows that have previously been recorded
- 9.7 How can I tell which encoder was used to record a program?
- 9.8 Myth won't recognize when I insert a CD or DVD
- 9.9 Myth removes commercials but when I watch the file elsewhere or transcode, the commercials are still there. Why?
- 9.10 Changing the volume and muting doesn't work, what should I do?
- 9.11 How can I get my channel icons?
- 9.12 Why can't my remote frontend play recordings even though I can see them in 'watch recordings' ?
- 9.13 How can I override mythfrontend settings which are stored in the database?
- 9.14 My recorded Programs do not Auto-Transcode
- 10 Live TV
- 10.1 Why is MythTV recording EVERYTHING I watch in Live TV?
- 10.2 When using live TV, why is there a delay between the moment I change the channel and the time the channel actually changes?
- 11 External links
What is MythTV?
Where can I ask questions?
Address queries to the mythtv-users mailing list. Please read the Mailing List etiquette page before posting.
The #mythtv-users IRC channel on irc.freenode.net can be helpful, but please do read all the documentation that you can before asking questions.
Questions can also be asked on a forum.
Is MythTV development dead? Where is the next stable release?
No, development is very active.
The MythTV developers typically package releases when they are stable and it's a good time for a release. Releases do not (as yet) occur on a fixed, predictable schedule. That's just how it works.
For a history of releases, see the [Github release page].
Does MythTV have a bug tracker?
Yes, at . This website runs Trac, which merges together a ticketing system with Subversion version management tools. The source code can be browsed through this page too.
What has changed in unstable/development since blah (time/revision)?
Undoubtedly several things have changed in the unstable branch of development. Interested parties are advised to subscribe to the mythtv-commits mailing list and read the commit messages as they come out. There is a searchable archive of list messages at http://www.gossamer-threads.com/lists/mythtv/commits/. You may also use git log to see commit messages.
When will Myth reach 1.0?
What's in a number? Numbering releases is extremely arbitrary, even more so in open source, even many commercial projects select version numbers out of the air and on the basis of how it will affect sales. Perceived 'wisdom' in the commercial world is that releases containing new features get a major version number and cost more, those receiving just bug fixes get minor numbers and cost less. In a project like MythTV where every release contains a new feature we'd be on version 23.0, but that doesn't give an accurate impression of where MythTV is in its development. MythTV is very stable, but it cannot be said that the developers consider it to be finished, and the version numbering reflects that.
Whenever the developers decide it's time to change the version numbering system they will.
Myth should be released more often! Why wait so long?
Because it's run by people donating their spare time. If you're impatient you can roll up your sleeves to help things move faster by contributing code. Most Linux distributions create packages from the current -fixes branch so you can benefit from post-release bugfixes.
Versions and database
I'm getting a protocol mismatch. What is wrong?
You are running different versions of MythTV on your frontend and backend. This occurs when a protocol change is implemented as part of a MythTV release. Update your systems to the same version to prevent this problem.
Can I use Release X or unstable/development X frontend/backend with release Y or unstable/development Y frontend/backend?
Quite often, development changes will incorporate database schema changes and/or backend protocol changes. All of your frontend/backend/mythweb/DSMyth installs must use the same database schema and backend protocols, or things will surely break.
This means that all parts of MythTV (mythtv, mythplugins, and myththemes) should be installed from the same revision or release version. Likewise, all computers running MythTV on your network (the master backend, slave backends, combined frontend/backend systems, dedicated frontends, etc.) should use the same revision/version. Therefore, when using packaged versions of MythTV, it is considered best that the same distribution be used on all systems.
Note, also, that there are multiple branches of development. At a minimum, these include 0.XX-fixes (which is usually used for packaged "binary" versions of MythTV) and "master" unstable/development (the main development branch). Components from different branches should not be mixed. Therefore, even if you acquire a specific revision from both 0.XX-fixes and unstable/development branches, you must choose to use either the 0.XX-fixes or unstable/development branch for all your systems.
Generally different revisions of the 0.xx-fixes branch will work together without issue. Therefore, if you must use different distributions or use multiple different platforms and plan to use packages, use the 0.xx-fixes branch on all your systems. Different revisions of the unstable/development branch, however, do not usually work together.
How can I go back from unstable/development code to release X?
If a backup of the mythconverg database was not made before upgrading, a downgrade will likely be impossible without recreating the database (thereby losing all recordings, recording history, settings, etc. in the process - basically starting from scratch). See the "Miscellaneous" section of the MythTV Documentation for more details. Newer versions of MythTV often upgrade the database schema (tables & columns change structure etc.) and older code is unlikely to work with newer database schemas.
If a pre-upgrade database backup is available, restore that backup. In the process, you will lose all information about recordings that occurred since the pre-upgrade backup was made.
While it may seem that MythTV works fine after downgrading versions, any data being added to the mythconverg database is likely being corrupted. And--if nothing else--new data is being inserted into the database in the old format. Therefore, running MythTV with the "upgraded" database after downgrading versions is a time-bomb. While MythTV may work fine now with the older version, it will surely fail when you upgrade later. So, the longer it is run in this broken state, the more data will need to be fixed (or the more data will be lost) upon later upgrades. Therefore, regardless of whether it seems to be working, the pre-upgrade database (from your backup) should always be restored when downgrading MythTV versions.
Do I really need this backend thingie?
Strictly speaking, no, it is not absolutely necessary for some features. Certain functionality (i.e. TV) relies on it - it's certainly not needed for use as a simple media player installation without TV features. mythfrontend WILL nag at users from time to time that it can't connect to the master backend if they opt not to run mythbackend on their system. This can be avoided by setting up a tuner-less backend (best done properly with a Dummy_Tuner)
Long term design goals (0.23 onwards) for MythTV will require the backend for most uses as video, music and other media will be served from this one process to all frontends.
Does the backend need to be running all the time?
If you are looking for the easiest solution then yes, it can't record when it is not running!
If you don't mind a challenge, then no, but you need to consider whether the hassle of starting mythbackend at the right times is worthwhile. If you want to shutdown the computer completely you might use Wake On Lan or a bios wakeup timer, but this can be complicated and unreliable. See Shutdown Wakeup, ACPI Wakeup and Mythwelcome for more details.
Well then, what about this MySQL thing?
MySQL is required for the frontend and the backend. It stores all the data they need to run and to do things, so yes, you will need it running whenever the backend or frontend are being used, which typically is all the time (see previous question).
I can't get <insert component here> working. Help!
A tried and true rule: Get it working outside of MythTV before you try to get it working inside.
MythTV isn't an operating system. It requires working components to work. You would never try installing a PVR application on Windows before you got your video card, capture card, and audio system working perfectly. Don't try to do it on Linux.
Confirm that all of your hardware is working with an application outside of MythTV before attempting to run MythTV. It will save you innumerable hours of barking up the wrong tree and generally make your MythTV experience better.
I want a low power, quiet computer to use as a frontend. What are my choices?
The Mac Mini is Apple's small form factor computer. It has the benefit of looking extremely nice and being extremely small. While it does have a fan, this is generally regarded to be so quiet that it is not an issue. Power consumption is very low (see http://support.apple.com/kb/HT3468), especially when using VDPAU for playback--much lower than even Intel Atom-based systems. The Mini can run either Mac OS X or linux (using Apple's Bootcamp or another virtualization system). Both the backend and frontend can run under either OS.
Another option is building your own system. There are many articles on the web about building low-power, quiet, small systems. For example, see Maximum Efficiency: Build A 25W Performance PC Using Core i5, G31 And E7200: The Real Low-Power Story, and Efficiency: Core 2 Nukes Atom On The Desktop.
Additional information is available at Choosing Frontend Hardware.
Can I run MythTV on a virtualized system?
Yes, but running a virtualized backend is not recommended when using a PCI-based tuner, due to timing issues. When asking for support, always specify any hypervisor or other form of virtualization being used to avoid wasting others' time.
Can I use MythTV without using my cable / satellite company's provided cable box?
- Normal Analog Cable: Yes, you can usually use MythTV without their provided cable box.
- Digital Cable, analog channels: In many cases you can tune the analog cable channels off the same line, but sometimes you will need to use the cable box.
- Digital Cable, digital channels: Certain cards, such as the pcHDTV 3000, can receive non-scrambled QAM-256 channels. These will generally only be your local HDTV channels. For all other channels you will need the cable box and an analog capture card, or a CableCARD tuner.
- Satellite: No, you will need the satellite box.
The Netherlands (Europe)
In the Netherlands all alternatives work using a MythTV system. Following the tested setups.
- DVB-S = yes (Tested with CanalDigital)
- DVB-C = yes (Tested with Ziggo)
- DVB-T = yes (Tested with KPN digitenne)
- analogue = yes (Tested with Ziggo)
Since I need to keep using my Cable/Sat box, how can I control it with MythTV?
A few different ways, and it depends on your specific hardware and the provider. Possibilities include RS-232 (serial), USB, FireWire, and IR Blaster (using the PC as a programmable IR Remote Control). See the HOWTO for details. At least some models of the Hauppauge devices (PVR-150, HD-PVR) include an IR output capability as well.
Does MythTV run on Windows?
Yes, as a basic frontend. MythTV compiles and runs on Windows using the MinGW toolset. All core frontend features work, including LiveTV, scheduling, and watching recordings. Most MythTV plugins, however, do not work and would need additional patches to operate in Windows. Refer to Windows Port for details on compiling MythTV on Windows.
For those who need an alternative to the lengthy and sometimes painful process of building MythTV on Windows, your best options are:
- Use mythlink.pl or mythfs.pl to create human-readable, sortable links to your recording files and share the file system using Samba.
- Use MythWeb and VideoLAN - With a few modifications, clicking on the "direct download" icon in MythWeb's "recordings" view, will bring up the recording, via a Samba share, in VideoLan. This solution is stable, works with v0.21+ of MythTV and multiple slave backends.
- Use a LiveCD MythTV distribution, such as Knoppmyth or Mythdora. This will allow you to boot up your windows box into mythfrontend in a way that won't touch your hard drive (so when you take the CD out and restart you'll go back into windows).
- Use MythTV running inside a Linux Virtual Machine running inside Windows. Tests using the free for personal use VirtualBox virtual machine show that this solution can work quite well. It's quite usable with a VM screen resolution size of 640x480 or 800x600. Adding realtime deinterlacing or larger screen sizes can result in some choppiness in the video playback. (tested with MythBuntu 7.10 running in VirtualBox 1.5.2 on Windows XP on an Athlon 64 X2 3800+ based system.)
- Run MythStreamTV. This will allow you to stream video from your backend to a Windows machine, on which you can use mediaplayer etc to watch the video.
- Run boxee.
- Run XBMC with the Mythtv plugin
See Play Recordings On Windows for additional community-developed options.
Does MythTV run on Mac OS X?
Yes. Both the frontend and backend run under Mac OS X. The Mac mini is a popular platform. In general, Intel-based Macs are capable of playing HDTV. On the backend, the Silicondust HDHomeRun and FireWire connected devices are supported.
Note that there is a bug in Firewire code regarding Big Endian number handling, which prevents LAM lock in Intel Macs. A fix as been submitted, but has not been included yet in current 0.24 binary build here : Intel-based Macs . A suggested workaround is to use Rosetta to run the backend in PPC emulation, but this is not possible in the current supplied build at Intel-based Macs , as it is not a Universal Binary and contains only Intel code.
Hopefully someone will upload complete Mac binaries (with the Firewire big endian fix) in the new Apple Mac Store, which will serve as the official distribution path for Mac OS X.
Which Linux distribution should I use?
If you are already comfortable with Linux then it's probably best sticking to the distribution you know best--as long as it provides pre-built packages for MythTV. If, however, you're a Linux novice, then your best bet is to go with one of the MythTV-based distribution, such as Mythbuntu or LinHES.
Note, also, that there is no reason to choose, for example, Ubuntu over Mythbuntu, then attempt to install MythTV on Ubuntu. There's no real difference between Ubuntu with MythTV properly installed on it and Mythbuntu, but starting with Mythbuntu will save a lot of time. The same applies for MythDora/Fedora and LinHES/Arch.
Please also note that if you choose an obscure, unknown distro, not many people will be able to help you with distro-related issues--and that most of the issues users encounter when trying to install, configure, or use MythTV are distro-related issues, and not MythTV-related issues.
A1: If you compiled X yourself you may have used -Os or another problematic optimization flag. Use -O2 when compiling Xorg 6.8 through 7.1.
A2: If you enabled OpenGL menu drawing, then this is probably because you do not have hardware accelerated OpenGL working.
I upgraded X, Y, and Z and now everything is broken. Help!
The one piece of advice I can most often give Myth users is to keep it simple. Distribution packages, automatic installers, and many other Linux packaging features have made it very easy to get a MythTV system installed by even the most novice MythTV user. This does not mean that you should arbitrarily upgrade on a whim.
MythTV is designed as a PVR appliance, first and foremost. Once it is working, it should be hands off, even for what seems the most innocent of upgrades. As tinkerers, most of us can't resist installing the latest this, or the newest that. But more often than not, a mass upgrade of every component on your system leads to trouble.
If it ain't broke, don't fix it
It may sound simple and foolish, but many people will tell you that once you have your MythTV system working, don't upgrade anything other than the MythTV application unless you absolutely have to. If you want to tinker with the latest of everything, build a slave backend and mess with it there.
Do I need to have the X Window System installed on my backend? I don't want it.
MythTV requires Qt for many non-gui related reasons. Qt is commonly misunderstood to only be a UI toolkit but it's much, much more. Qt requires the X Window System libraries.
You are not required to boot into graphical mode (see the documentation for your operating systems for details on how to boot to a console login). The mythtv-setup program run on the backend system is a graphical interface. You can either run this locally on the backend or use X11 forwarding to display the output of the program on another system.
If you run mythtv-setup via X11 forwarding, and you don't run a frontend or any other X programs on the backend, you don't need to have an X server or graphics drivers on the backend. You do still need the X window system libraries, though.
If you're still concerned about the space that X takes up, consider for a moment that your entire system is built to process multi-gigabyte files, so a few megabytes for X libraries (approximately 10MB) is a drop in the bucket.
Why am I getting QMYSQL3 errors?
QSqlDatabase warning: QMYSQL3 driver not loaded QSqlDatabase: available drivers: Unable to connect to database! No error type from QSqlError? Strange... couldn't open db
There are actually a few causes for this error that all revolve around the same basic problem, and that problem is that your Qt binaries are missing their MySQL support (which is required by MythTV). If you have Qt-3.3.x, either your Qt was not compiled with MySQL support (via -plugin-sql-mysql if you compiled it yourself), or you've accidentally left out the sub-package containing libqsqlmysql.so. If you have Qt-3.2.x, it's possible that the plugin is actually present but not in a directory your library linker has been searching.
To determine if the Qt MySQL plugin is actually present your system, run the following command:
find /usr /opt -name libqsqlmysql.so 2>/dev/null
If this command returns a filename (and you are using Qt-3.2.x) then you probably need to add this directory to the list of places your system's linker searches. So for example if it returns "/usr/lib/qt-3.2.1/plugins/sqldrivers/libqsqlmysql.so" you would add "/usr/lib/qt-3.2.1/plugins/sqldrivers/" (without the quotes) to /etc/ld.so.conf and then run `ldconfig` to rebuild the linker's cache.
If however it returns nothing then depending on your Linux distribution, adding this support may be as easy as installing a package (qt-MySQL for Fedora Core for instance, libqt3c102-mysql on Debian Sarge) or as nasty as recompiling Qt yourself with support for it. In Gentoo, putting 'mysql' in your USE flags and doing 'emerge qt' will also solve this problem.
Why am I getting QMYSQL3 Unable to connect?
I am running gentoo and got this issue when setting up the secondary backend on a second pc:
$tail -f /var/log/mythtv/mythbackend.log QMYSQL3: Unable to connect Database error was: Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2) QSqlQuery::exec: database not open QSqlQuery::exec: database not open 2009-06-27 19:46:41.305 DB Error (KickDatabase): Query was: SELECT NULL; No error type from QSqlError? Strange... 2009-06-27 19:46:41.356 Cannot login to database? 2009-06-27 19:46:41.357 Cannot login to database? Cannot login to database?
this occurred on my secondary mythtv box. solution was to: user $ mv .mythtv .mythtv.temp user $ mythtv-setup and point to the remote mysql server. then cp -R /home/user/.myth /home/mythtv then restarting the /etc/init.d/mythtvbackend restart
I get a database 145 error. What is it?
Errors that look like this
QMYSQL3: Unable to execute query Database error was: Can't open file: 'inuseprograms.MYD'. (errno: 145)
An errno of 145 mean a corrupted database table. The mysqlcheck program from MySQL is used to repair tables. If mysqlcheck finds errors, you can run either (you will be promted for your database password)
mysqlcheck -u root -p --repair mythconverg
to repair damaged tables. Be advised that sometimes repairs can cause data loss. It is always recommended that you perform a database backup often so that if problems arise, you have something to restore.
Are there any packages for MythTV for my distro?
Please see Packages.
Do I really need a window manager for a frontend only box?
Do you use one or more windows, such as the mythfrontend window? Then, yes, you should use a window manager. Without one, you are very likely to run into focus issues (the frontend won't receive keyboard and/or remote input while watching a recording/live tv/video file/etc) or stacking/layering issues, so running without a window manager is an unsupported configuration. There are plenty of very light-weight window managers, such as LWM, TWM, Ratpoision, blackbox/fluxbox/*box, XFCE, and so on. Using one of these should never impact your performance, and will prevent invalid "bug" reports of focus issues that are actually due to not using a window manager.
To put things in perspective, after accounting for shared libraries that you need to load for other parts of X/MythTV, the incremental cost of running FluxBox is less than 1MB of RAM. The incremental cost of running RatPoison is only 300KB. If your system needs that 1MB or less of RAM, that's not all the RAM it needs (so you're better off getting more RAM than trying to run without a Window Manager). See, also, http://www.gossamer-threads.com/lists/mythtv/users/230352#230352 and http://www.gossamer-threads.com/lists/mythtv/users/230354#230354 .
If you are using an older install of MythDVD you may still be using mplayer to play DVDs. Mplayer doesn't support DVD menus. MythVideo now uses an Internal player to play DVDs which supports all DVD functionality including menus. If you change the DVD Player Command from mplayer to Internal (Capital I) you should be able to use DVD menus.
How do I remove recordings that no longer exist on disk?
If you have deleted some of your recording files through an external (non-MythTV) program, MythTV will not delete recording metadata for those recordings without explicit permission to do so. This means that MythTV will not auto-expire any of the recording entries (as doing so will not free up any disk space; and, therefore, does not accomplish any of the objectives of auto-expire). Similarly, the recording metadata can not be deleted from "loosely-integrated" client applications, such as MythWeb. Instead, the recording metadata must be deleted through mythfrontend.
To delete the recording(s), go to the Watch Recordings screen in MythTV. Then, select the recording metadata you would like to delete. Use the MENU key (by default 'M') once or twice to bring up the recording menu. You should see a dialog that says, "Recording file can not be found," and specifies the recording's title and start time. At this point, you may select "Show Program Details" to see details of the recording (including subtitle (episode title) and description). You may use Esc to exit the recording details screen. If you would like to delete the recording metadata, press MENU, again, to bring up the recording menu, and select Delete. You should see a dialog that says, "Are you sure you want to delete:" and then lists the recording title and start time. Select either "Yes, delete it" or "Yes, and allow re-record" to delete the recording metadata. At this point, you will see a dialog that says, "Recording file does not exist. Are you sure you want to delete:" and then lists the recording title and start time. Select "Yes, delete it" to remove the metadata. (Note, also, that if you chose, "Yes, and allow re-record," from the first dialog, choosing, "Yes, delete it," from the second dialog will not change your decision to allow re-record.)
Alternatively, after selecting the recording, use the DELETE key (by default 'D') to bring up the delete dialog. The dialog says, "Are you sure you want to delete:" and then lists the recording title and start time. Select either, "Yes, delete it" or "Yes, and allow re-record" to delete the recording metadata. At this point, you will see a dialog that says, "Recording file does not exist. Are you sure you want to delete:" and then lists the recording title and start time. Select "Yes, delete it" to remove the metadata. (Note, also, that if you chose, "Yes, and allow re-record," from the first dialog, choosing, "Yes, delete it," from the second dialog will not change your decision to allow re-record.)
Note that the reason MythTV requires explicit permission to delete recording metadata when it cannot find the associated recording file is so that it does not create orphaned multi-gigabyte files if the filesystem that contains the recording file is not available at the time MythTV tries to delete the recording. Therefore, before allowing MythTV to delete metadata for any recordings for which it cannot find recording files, make sure you verify that all recordings filesystems are mounted and available on all backend hosts.
See, also, find_orphans.py.
How long does mythfilldatabase take to run? It seems to be stuck in a loop?
It can take a few minutes to a long time, depends on how much data and where you are getting it.
It's actually not stuck in a loop, it grabs data for each day, processes it and goes onto the next day, so don't worry about it looking like it's stuck in a loop, it's really not.
The popups in mythweb don't work
You have a version of php installed which does not have json support enabled.
How does mythtv determine tuning frequency?
For satellite channels, MythTV uses a starting frequency, then uses the information specified by tables in the digital stream you receive on that frequency to determine the other channels in the stream. For all other types of channels, MythTV contains internal tables of the standardized frequency tables for that area.
What are the types of channels I can record and what type of capture card(s) do I need?
In general, channels are received by MythTV through either an antenna connection or a cable connection to the capture card(s). To find channels in your area, you can do a search using labs.zap2it.com. You will be able to determine which channels are over-the-air broadcasts (whether NTSC, digital TV (DT) or High Definition (HD)). For example, you may find that your cable provider provides you with "Channel 10 KXXX", and "Channel 10 KXXXDT". The former is an NTSC broadcast and the latter is a digital broadcast.
In general, you should be able to receive at least one digital signal per local station that you can receive normally over the air.
To capture NTSC broadcasts, you will need a card like the PVR-350. That card cannot recognize digital or HD broadcasts. To capture those, you will need a card such as the pcHDTV 3000 (although the pcHDTV 3000 also has the capability of capturing NTSC as well).
If you live in an area where Digital Terrestrial Television (DTT, also known as DVB-T) is an option, then this is a particularly good option, as the received signal is already MPEG-encoded, lowering CPU requirements for the backend. The author of this paragraph has measured recording three 4.5Mbit/s DVB-T channels simultaneously as requiring about 7% CPU on a Celeron 1.7 machine (using Hauppauge Nova-T and Nova-T-500 tuner cards on FC8rc3).
Where do I get my TV guide data outside the US?
MythTV can integrate with a separate set of scripts maintained by the XmlTv project to provide guide data for countries outside the USA. Please refer to the XmlTv page for more information. For digital broadcasts, MythTV may alternatively use the Electronic Programme Guide data broadcast as part of the DVB or ATSC specification, known as generally as EIT.
How many capture cards do I need?
You need one capture card for each program you wish to record at any given time, and one extra, if you want to simultaneously watch live TV. The exceptions to this rule are the PVR 500 which contains two NTSC tuners and the Silicondust HDHomeRun which contains two ATSC/QAM tuners; they consequently count as two capture cards each. Examples:
- With a single capture card you will be able to record a single program or watch live TV at any given time
- With three capture cards you will be able to record up to two programs whilst still having the ability to watch live TV. You may then begin recording a third program but will then lose the ability to watch live TV.
DVB cards can often watch / record more than one channel per tuner, provided the channels broadcast from the same multiplex.
How much disk space do I need?
The short answer is as much as you can afford. If, however, you're not made of money, here are a few guidelines:
- Video recorded via a PVR x50 typically comes in at 2GB/Hour
- Standard Def DVB will typically be 1.2-2GB/Hour
- High Def video will be somewhere between 3.5GB and 7GB/hour
Where have the options for the Fast Forward / Rewind jump sizes gone?
This functionality has been moved to the Playback Groups setup menu. Here you can create Groups to apply different skip, jump and stretch to any programs you want. You'll find it at Utilities/Setup -> Setup -> TV Settings -> Playback Groups
MySQL sucks! Can I use a different database?
No. Supporting multiple database engines is not considered a worthwhile use of the developers' time. Furthermore, simple or lightweight databases like SQLite just can't cope with MythTV's needs.
It is planned that in the future MythTV will move to use embedded MySQL and running a separate MySQL server will no longer be necessary.
What are my options for connecting my computer to my TV?
There are many informative posts on this subject in the mythtv-users mailing list archive by Cory Papenfuss.
HDMI is the current standard for HD connections. Many new onboard and PCI-E video cards support it directly, as do the current proprietary NVIDIA drivers. The 2.0 standard supports video and audio in one cable.
TV out on a graphics card.
Lots of graphics cards come with a TV out these days, usually in the form of an S-Video out which can then be converted to SCART if you live in Europe. The main piece of advice is to ensure that the graphic card you are thinking of has Linux drivers that support the TV out functionality (until recently some ATi cards had problems with this). If noise is important to you then try and get one without a fan.
A Scan converter
This is a single box, which converts the VGA signal from your video card into NTSC/PAL/SECAM for your TV. This has the advantage of working with any graphics card that has drivers available, and is relatively simple, but the output probably won't be frame- or scanline-accurate.
A homebrew VGA to SCART conversion circuit
If you're a dab hand with a soldering iron and you live in Europe then you can cheaply make a circuit which will enable you to take the VGA output of the video card and plug it straight into the SCART socket on your TV. Instructions on how to make the circuit are here. NVIDIA GeForce 440MX cards work well, and a fanless design is preferred. The author of this paragraph recommends using Linear Blend deinterlacing, rtprio scheduling (by editing limits.conf), disabling OpenGL sync in MythTV, but leaving the video texture and video blitting sync options in nvidia-settings set. Note that you may need to modify the On-Screen Display themes and MythTV GUI appearance settings to make sure the graphical elements are properly framed on your TV. Recommended PAL modelines are:
ModeLine "1024x576pali" 19.750 1024 1056 1152 1264 576 581 586 625 -hsync -vsync interlace # 16:9 ModeLine "720x576pali" 13.5 720 722 786 864 576 581 586 625 -hsync -vsync interlace # 4:3 DVB ModeLine "768x576pali" 14.75 768 789 858 944 576 581 586 625 -hsync -vsync interlace # 4:3 Analogue
Direct VGA connection.
If your display supports it (some LCD TVs have a VGA input) this input type is simple, but you may be limited with supported resolutions. This is a particularly a problem, for example, if your TV is widescreen, but only accepts 1024x768.
Direct DVI connection
Many video cards have a DVI connection these days, and it's available on some TVs as well. There is the possibility of limitations with supported resolutions for this case as well.
All my fonts look like they are the wrong sizes, how can I correct this?
MythTV sizes fonts as specified by the MythTV theme (regardless of your configured DisplaySize or DPI in X). Therefore, if your fonts do not look right, you first need to ensure you have installed the font your selected theme is using. If you have the font installed, and you still don't like the font sizes, you should choose a different theme.
Fonts distributed with themes are loaded automatically. Note, however, that some of the MythTV themes use MS core web fonts (often the msttcorefonts package in many distros), which may not be redistributed. If a theme-specified font is not installed, the log file will show errors such as, "MythFontProperties, Error: Failed to load 'Arial', got 'DejaVu Sans' instead".
However, many other applications are designed to operate in a limited range of display pitches (dots per inch). To find out what your vertical and horizontal pitch is (with the X display running) use the command:
$ xdpyinfo | grep dots
If the response from this isn't 100x100 dots per inch, you may want to change your system configuration to force X to calculate dimensions appropriately for non-Myth program usage. Unfortunately, there are many ways to specify the pitch, but X will use only one. The "-dpi" command-line argument to the X server takes precedence over all others. Note that some distributions use this argument in their X start scripts (such as the "startx" script) or by calling "startx -- -dpi 75". If your distribution does this, you'll need to modify the start script to either specify 100 DPI or simply remove the option (preferred) and use the configuration files as described below.
If your system does not specify a command-line argument to set the DPI, you should configure the pitch using the X configuration file (XF86Config or xorg.conf, usually in the /etc/X11/ directory ). The standard X approach for configuring the pitch is through the "DisplaySize" setting. This approach will work with all video card drivers (if using an NVIDIA card, however, see below). To set 100x100 DPI with the DisplaySize option, add a line:
DisplaySize x y
Under the "Monitor" section in your X configuration file. Where x = (horizontal resolution)*0.254 and y = (vertical resolution)*0.254, both rounded to the nearest integer. See the Display Size page for appropriate settings for common monitor and TV resolutions or if your display is using non-square pixels (i.e. the ratio of the physical display's dimensions are different from the ratio of the X and Y resolutions). It's important to choose a DisplaySize whose aspect ratio is the same as your physical display's aspect ratio, so if you have a 16:9 TV, choose a 16:9 DisplaySize. If you have a 4:3 TV or monitor, choose a 4:3 DisplaySize. If you have a 16:10 widescreen monitor, choose a 16:10 DisplaySize.
Note that you may also specify a font pitch of 100 dpi (which is not the same as specifying a screen pitch of 100 dpi) by adding the following line "Xft.dpi:100" to /etc/X11/Xresources or ~/.Xresources.
If you're using NVIDIA display drivers, see, the section Specifying DPI for NVIDIA Cards
If this doesn't solve the problem then the chances are it's a broken font package or something. Feel free to post the problem to the mailing list at this point, but make it clear you know you're running at 100dpi or you'll get lots of requests telling you to make the changes listed above.
Should I use the mailing list to find out where I can download TV shows/Films?
No. When you use MythTV you will find out that it is a very useful piece of software that can completely change the way you watch TV. It is not, however, a means to circumvent copyright and this list is no place to be asking for tips on how you should do so. See, also, Mailing List etiquette.
Why can't I see all of my desktop/MythTV screen on my TV?
Probably because of overscan.
Why aren't my new recordings showing up in Watch Recordings?
You probably have a filter set from a previous session. Hit MENU (press M on your keyboard) in the Watch Recordings screen until you see a menu with options, "Change Group Filter" and "Change Group View", and verify that both the filter and view are set to include All Programs.
How do I import recordings from other sources into Myth?
Place the video files into MythVideo directories and scan for changes.
I have no interest in recording TV but I wish to use Myth as a music/video jukebox. Is this possible?
No. Myth has two plugins called MythMusic and MythVideo which can be used to handle audio and video libraries, respectively. However, mythfrontend requires a running mythbackend to connect to, and mythbackend requires at least one properly configured capture card.
Can I temporarily keep MythTV from attempting to record my scheduled programs?
If you're going to, for example, have your cable TV feed temporarily disconnected, and you don't want to record static, but you don't want to lose your schedules:
A1: Go to the "Upcoming Recordings" page of the frontend (or MythWeb) and add a "do not record this episode" override for each scheduled recording during the expected service outage. (This solution will not work for episodes with empty subtitles or descriptions because they are exempt from duplicate checking. You can simply delete these recordings after they have occurred and they will have no impact on future recordings.)
A2: Use the frontend or MythWeb to edit each recording rule and set the "Inactive" flag. If you have a large number of recording rules, this is probably not a good approach. It also is difficult to undo after the fact if you have some recording rules that are normally inactive (i.e. an inactive "First Episodes" rule whose sole purpose is to alert you of new series).
A3: Modify whatever starts your machine's backend to add the --nosched flag, like this:
This will cause the backend to run normally, but not execute scheduled recordings. When your problem has been cleared up, remove or comment out that switch.
Myth won't record a later showing of a program
The scheduler, by default, will not bump programs of higher priority even if there is a later showing as it assumes that you want to see higher priority shows sooner rather than later. To override the scheduler's decision, you may create override rules to tell MythTV to "Do not record this showing" of the earlier showing and, if necessary, "Record this specific showing" of the later showing.
If you feel it is acceptable to let the scheduler bump high-priority recordings to later showings automatically, there is a setting in the frontend setup to allow rescheduling of higher priority items that can be checked. Just be aware, that exciting episode of 24 might be recorded a week or two later leaving you in the dark and plugging your ears as your friends talk about it.
Myth keeps recording shows that have previously been recorded
By default MythTV will not record shows it recognizes as having already been recorded. There are some circumstances, however, in which it does rerecord shows - see Duplicate_matching for more detail.
How can I tell which encoder was used to record a program?
In the "Upcoming Recordings" display, the encoder that is going to be used is shown. There is no corresponding field in the "Previously Recorded" display, because the encoder numberings could change over time. The way to find out which encoder was used is to consult the myth-backend logs.
Once upon a time, Michael T. Dean wrote:
There's an ugly hack at http://www.mythtv.org/wiki/Which_recorder.pl that will stick the information in the backend status page when used with the Miscellaneous Status Script.
Myth won't recognize when I insert a CD or DVD
First, make sure that the media monitoring is checked in the general settings. Also make sure that it is enabled in the plugins for MythVideo or MythMusic. Lastly, check if your mount point for your drive is set to use filesystems of "udf, iso9660" instead of "auto" which can correct problems with lowercase directory entries failing to be detected on DVDs.
Myth removes commercials but when I watch the file elsewhere or transcode, the commercials are still there. Why?
See Removing Commercials for details. The simple answer is, "Because commercial detection is detecting, not removing, commercials."
Changing the volume and muting doesn't work, what should I do?
Ensure that you've got the correct audio output device. To route audio through the default ALSA Mixer, change /dev/dsp to ALSA:default. To route the audio through JACK, change the setting to JACK:
How can I get my channel icons?
Please see Channel_icons.
Why can't my remote frontend play recordings even though I can see them in 'watch recordings' ?
Ensure that all your MythTV machines have different hostnames. Myth works out whether or not to stream a recording (live tv or otherwise) by determining the frontend's hostname. If the frontend hostname is the same as the backend's hostname, it will try to play the file 'locally'. Having different hostnames for machines is useful (and correct) in many other scenarios too!
Also, make sure your frontend and backend have the same timezone and have roughly the same idea of what time it is.
How can I override mythfrontend settings which are stored in the database?
My recorded Programs do not Auto-Transcode
There are two MythTV settings that govern auto-transcode:
- In Mythtv-setup, General (Job Queue) > "Allow transcoding jobs" - near the bottom, a checkbox.
This setting sets the default for new recording schedules.
- In Mythtv-setup, Recording Profiles > Hardware DVB Encoders > Default > Enable Auto-Transcode after Recording
This must be enabled in your hardware recording profile, it won't allow it to auto-transcode unless it is specifically set.
Why is MythTV recording EVERYTHING I watch in Live TV?
MythTV is not a TV, it's a PVR. When you watch TV, the ability to pause, rewind, and skip commercials is because it is actually recording everything you watch. As an added bonus, when you are watching something and decide you want to keep it, hitting record will just tag the existing recording as a keeper. The LiveTV page has lots more info, but here are the three most FAQs.
But my Harddrive keeps filling up from all these Live TV recordings! How do I stop it from recording?
- Short answer: You can't.
- Long answer: You can't stop it from recording, but you can stop it from filling up your harddrive. MythTV is designed with an autoexpire concept. Every time Myth tries to watch or record something, it first makes sure that it has room for it, and will delete the oldest available recording to make space. You can specify how much free space to leave, but it is recommended to dedicate a partition to Myth recordings and tell it to leave at least one gigabyte free. Live TV recordings by default have a shorter lifespan than normal recordings and a lower priority, so they will be expired before any recordings are.
It didn't used to do this, why did it change?
- It always did. In versions before 0.19, it saved live TV recordings to a separate file (a ring buffer), which stayed within a certain size range. It got complicated when you have more than one tuner and more than one live broadcast being viewed. There was no easy way to transfer from that ring-buffer file into a normal recording, so even though you can pause the TV, there was no way to keep it (and if you paused for long enough, another scheduled recording would come around and wipe out your live TV buffer).
I don't want it to delete things unless I tell it to!
- You have the option when recording a program to have it auto-expire or not, as well as the ability to change that setting on an individual-recording basis. If no programs are set to auto-expire, however, it will run out of space very quickly.
When using live TV, why is there a delay between the moment I change the channel and the time the channel actually changes?
When you are watching live tv in Myth, you are actually watching content which has first been written as a file to the hard disk. In doing so, the 'live TV' that you are watching is actually TV that has been captured a few seconds beforehand. Whenever you change channel, the old file has to be removed and a new file created. The fact that this takes a couple of seconds is responsible for the gap you are seeing in between channel changes.
Although this doesn't sound too good, it is necessary to create this file so that you can do cool stuff such as pausing and rewinding live TV. The 'approved' method of using live TV is to use 'browse mode' so that you can see what is on any given channel without having to change to that channel itself. The other main answer to this query is that once you have MythTV, you'll rarely use live TV anyway on the grounds that all you favourite programs will be sitting on the hard drive ready to watch.
Of course if you do have any coding skills, there's always the chance to have a look at the code to see if channel changing can be made any faster.
- MythTV.org project page
- MythTV-Users mailing list archives
- Mythportal.be : community site for Belgian and Dutch users
- Mythblasterz : Inexpensive IRblasters for with 5+ meter range
- Jarod's guide for Fedora
- LinHES (former Knoppmyth), a LiveCD with MythTV
- Mythbuntu : Standalone PVR system based on MythTV and Ubuntu
- MiniMyth : a diskless system that netboots
- Mythdora : a DVD that installs MythTV
- Developer Documentation
- Rage 3D Linux forums : TV out advice for those with ATi cards
- IVTV mailing list archives