Sunday, May 21, 2006

Building my own MythTV, day 1

Long and short: in return for moving data off an old PC's HD to the owner's new HD, I inherited the PC. It so happens that it has 512Mb RAM, 200Gb HD, a DVD burner, an nVidia card and a mediocre 450MHz slot 1 PIII.

In other words, a reasonable candidate for a Linux PVR. Since the box was free, my objective is to get the whole thing done for less than $200.

Myth is a little different than your regular Linux distro. ext3 is apparently unsuitable for large files like the ones Myth creates and deletes, so the instructions say to set aside a separate partition in XFS. I'm following Daniel Hyams' instructions because they're made for the PVR card I bought, the $80 Hauppauge PVR-150. Nota Bene: I fucking hate Fry's. If I'd gone into CompUSA first I would have been done with my shopping and left with my dignity inside twenty minutes.

The Hauppauge series are prized in part because they have the Conexant MPEG2 encoder chip that relieves realtime load from your CPU. The PVR-150 uses the same "microphone" IR receiver the AlchemyTV DVR does, except that it also features a separate IR transmitter as well (for controlling set-tops).

Getting the video out to the ancient 19" Magnavox is another issue. This TV was bought to watch President Bush debate. That is, President Bush debating then-Governor Clinton, so it's not going to have a DV or VGA input on its back. Because we're doing this on the cheap, replacing the video card is out of the question. Fortunately, we've already got a Radio Shack RF converter connected to the television for the DVD player, so what we need is VGA to SVHS. Enter the Grandtek GEZ-1000, a $40 VGA-SVHS cable which encapsulates the converter circuitry and uses a USB cable to leech the 5v it needs from your computer instead of requiring a brick. These were clearly designed for notebook computers, but it's hard to argue with something that eats less space and costs less than the boxes that do the same thing. Had I been thinking more clearly by the time I was at CompUSA I would have purchased one there; I ended up ordering one online. It'll arrive in the mail in a few days and I can test it then.

Since the TV's on the other end of the room from the router, for now the internet connection will be managed by the AirPort Express we installed last year. I'll have to look into whether the kernel is competent at managing a generic wifi card before sinking $70 into that.

Some considerations for those who'd follow in my footsteps:
  1. Hyams' instructions were written soon after the Breezy release, so parts of his timetable are optimistic. If you're not on a T1, they're extremely optimistic; prepare to wait over an hour for apt-get update; apt-get upgrade to finish. There are a few other places where the downloads are either large or slow depending on connection.
  2. I prefer KDE to Gnome. That said, the instructions are optimized for Gnome when it comes to configuring startup and repairing broken scripts that Myth installs. Accept this, use Ubuntu not Kubuntu, and move on.
  3. This process involves creating a lot of users and passwords in various places. Keep a paper notepad nearby and take notes. Resist the impulse to use the same uname/pw everywhere; this is a box with a live internet connection.
  4. There are two PVR-150 models out there; the one with "MCE" in the title is the one you don't want. It's built for Windows XP Media Center Edition and doesn't have a remote. While it has a few more ports on the back, it doesn't have video out either. Skip it and go for the plain PVR-150; it's cheaper as well.