Most folks buy their TV's at places like Sears or Best Buy, and there's a lot to be said for plunking your credit card down and driving home with a functional television set. But that's not my style. I've been using a Commodore 64 color monitor hooked up to a VCR since the late 80's and it's worked great. On the other hand, VCR's are going the way of the dodo and a 13" television with weak mono sound isn't much fun so I should probably upgrade.

Given my fondness for doing things the hard way I've decided to hack together a computer-powered television set using parts that I've mostly already got lying around the house.

Bill of materials:

• HP A2094A monitor - a 20" RGB monitor from an old HP X terminal. Picture tube is a Sony Trinitron.
• Intel 815-based motherboard with a 900MHz PIII.
• AverTV tuner card. The only component I've had to buy so far, $20 at Compusa.
• Sound card (not sure which one yet but the 815 motherboard has built-in sound)

As a proof of concept I think I'll try to get my office computer to work with the TV card. The only problem is that my office computer is a diskless workstation so I've been using pre-built kernels from the LTSP project at http://www.ltsp.org/, and their kernels don't have all of the drivers that I need.

Change of plan: I found a project called MythTV http://www.mythtv.org/ which can run in client-server mode. This will allow me to run the tuner in a server in the basement and the display on a workstation in the den.

I wanted to put the tuner card in my 1U VA Linux server but for some reason the card wasn't seen by the operating system. Maybe the little right-angle riser card was broken? In any case it worked just fine in my Intel 815 mobo which will allow me to get it working but then I'll have to move it to my other server, I guess. That's the price you pay for a 1U form factor.

Building MythTV was somewhat challenging. It has lots of dependencies but they're spelled out on the website. This is one of those times where Debian is a good and bad thing. Good because it's so easy to find and install software, bad because many people expect files to be where Red Hat puts them and Debian often puts them somewhere else.

On the other hand, why build when you can apt-get? http://dijkstra.csh.rit.edu:8088/~mdz/debian/dists/unstable/mythtv/

Here's a command-line recorder: http://www.stack.nl/~brama/vcr/

http://tvtime.sf.net/

2003-06-20 - Spent a couple of hours fooling around with the setup. Was able to get the capture part working just fine (had to compile i2c as a module, also v4l stuff which is very old in the kernel). I can run xawtv and capture snapshots and they look fine. Display is FUBAR - I've installed X and DRI and it seems to run OK, but it splashes pixels all over the display. Looks almost as if you took the red, green and blue parts of the pixels and put them side by side instead of combining them into a single pixel. Guess I'll need some help.

In the mean time I figured out that the cable no longer provides basic signals (it did when we moved in) so I have to use a powered antenna to play around, which works poorly since I've got all of the gear in the basement. Comcast wants $45/mo for basic cable which seems amazingly expensive to me. I would get a $20 discount on the cable modem but I don't care since my company pays that.

2003-09-05 - I've switched over to RCN and signed up for cable tv and made a little more progress. The display problem above must be an X Windows configuration problem because I can run xawtv on the server but display it on my diskless workstation and the picture is fine (although not the most crisp since it's going over the network). It's pretty cool to see that X can stream TV over the network.

2003-09-13 - Got sound and video working on the server. No real problems - I used the debian kernel, alsa, and bttv packages.

2003-09-14 - Moved the tuner card to "phoenix", my Compaq DL380 server. Now I can use the PIII desktop as a client and (hopefully) run it diskless. I was using the on-board sound on the desktop so I had to use a SoundBlaster Live! card that I had lying around in the server.

2003-09-16 - Turns out sound was more complicated than I thought. Mythtv always records and then plays the recording back; that's how it can do things like pause and rewind "live" tv. So you need to set up the sound card so it is recording the Line input but it must be muted. The biggest hassle was figuring out what the different features of the SoundBlaster Live card were and how they worked.

Here's a dump of the card with a working config:

• mythtv-mixer.txt: soundblaster live mixer configuration

All of the pictures had strange jagged lines when things moved. It turns out there's an option to "de-interlace" the video on the client side. It crashes on the PII machine but works fine on the PIII.

XVideo and Xinerama don't play nice so it looks as if I can't watch TV on my dual-head machine. That's sort of OK since it doesn't have quite enough CPU either.

2003-09-19 - the wierdest problem so far. Cable channels 2 and channel 14 (WGBH-2 and WGBX-44) didn't have the right audio - they had the BBC instead. I as seriously stumped until I noticed that channel 6 (WFXT-25) was in Spanish. Googling for "Mythtv SAP" did the trick. Turns out there's some really random bttv module option that fixed it:

options bttv audiomux=0x56664e

In debian you add this to /etc/modutils/arch/i386, in other flavors of GNU/Linux I think it's =/etc/modutils/.

See http://www.gossamer-threads.com/archive/MythTV_C2/Users_F11/bttv_driver_&_Aver_Studio_TV_Tuner_P73141/ for more info.

2003-09-23 - It turns out that video files are big. Who knew? I managed to wedge this server last night by filling it up with The Simpsons videos. Probably a good idea to put the recordings on a partition other than /.

Installed Myth Weather which is quite cool but I doubt that I'll use it.