Like many people, I went out into the great choas known as Black Friday after a deal.
In my case I was focused on obtaining an Olevia 237T 37″ LCD television being sold at Target for the low, low price of $549.00.
After getting it home and plugging it all into my MythTV system, I ran into problems. First of all, since the tv had a vga input, I used the vga output of my video card instead of the svideo output. Initially I got no video, but then I realized I needed to undo some of my xorg.conf changes since I had changed the output.
After fixing the xorg.conf problem to not use the svideo port (thank you SSH!), I ran into other small problems.
Getting the resolution output right
The 237T has a native resolution of 1366×768, which according to an article at CNET.com is the most common resolution, yielding an output of 768p.
It turns out that I needed a particular video modeline in order to make the tv work properly. This required a great deal of research since manually calculating a modeline is not something that I really wanted to undertake. After finding a few online calculators, I found that I could not use them since the Dot Clock Frequency was not something that was included in the manual for the tv. So I diligently searched on the Internet to see if I could run across someone else who had this model tv (or the slightly improved 537 series) that had solved the problem. On the MythTV wiki, I ran across two entries for the 537h. I tried them both, but unfortunately the source display on the tv still reported a resolution of 1024×768. After trolling the xorg.conf logs, this turned out to be due to a failure of either modeline to be validated.
Digging ever deeper into the realms of HDTV screen resolutions and the xorg.conf options, I found that the binary, proprietary Nvidia drivers give you something that can help out a lot here, Appendix J. Programming Modes. This enables one to specify a series of validated modes and the driver will automatically validate them and use the correct output settings for the first mode that is found to be valid.
Here is what I ended up using in my xorg.conf file:
Section "Screen" Identifier "Screen0" Device "Videocard0" Monitor "OleviaHDTV" DefaultDepth 24 SubSection "Display" Viewport 0 0 Depth 24 Modes "1360x768_60" "1280x720_60" EndSubSection EndSection
Getting the right TV output
The next hurdle was to make sure that I got the right output of each of the MythTV applications.
Xine
In the configuration of the DVD player or the Video player, make sure that you launch xine with the following command:
xine -pfhq -D -r anamorphic
In theory xine should automatically display the video output exactly as is on the media, but using the command above will ensure that your get a fullscreen display. (Thanks to a posting in the Freevo-users list by John Molohan for this)
Mplayer
In the DVD or Video playback configuration you can use the following command to launch mplayer to use the correct aspect ratio (Thanks to Jarod Wilson for this tip):
mplayer -fs -zoom -quiet -monitoraspect 16:9 -vo xv %sYou can also set these same configuration options in your mplayer configuration file (~/.mplayer/config):
## Audio Output ao="alsa"
ac="hwac3,"
## Verbosity
really-quiet="1"
## Video Out
vo="xv"
## Scaling fs="yes" zoom="yes" monitoraspect="4:3"
double="yes"
## Misc
nojoystick="yes"Internal DVD player
The MythTV built-in dvd player should display the video correctly by default.
Live TV output
When watching live television, you have a few options:
- Leave the aspect ratio alone
- Change the aspect ratio to be 4:3 or 16:9
- To set the aspect ration to be Fill
- To set the aspect ratio to be 4:3 with zoom or 16:9 with zoom
Each of these has it’s own drawbacks, but I have gotten the best results using 16:9. This setting is in the Playback options of the TV section of the MythTV setup.
References