My blogging has been sparse recently because my usual blogging time has been taken over by my Personal Video Recorder (PVR) assembly project. A PVR is a do-it-yourself TiVo. The main advantage over TiVo is that you don’t have to pay anyone a monthly subscription fee. The disadvantage, especially if you want to use your PVR with a TV instead of a computer monitor, is that you’re dealing with bleeding edge technology. That means you’ll find lots of debates about the “right way” to configure the system and you’ll inevitably hit a few snags while setting things up. But if you’re a geek, that’s also what makes it fun. And besides, according to the New York Times, everybody’s doing it.

My friend and co-worker Chris wanted to build one too, so we decided to pool our expertise and save on shipping costs by buying our components together. We built our systems from scratch. Where things got tricky was deciding what to do for the TV tuner card, video card, and PVR software. We did lots of Googling and browsed through the SageTV forums to assess our options (the Build Your Own PVR site was also helpful). The only thing everyone agreed on is that you need a TV tuner card with hardware-based encoding, so that writing your favorite TV shows to files doesn’t slow your PC to a crawl.

Where folks disagreed was on how to get the best picture when decoding the files back to your screen. If you use an ordinary TV tuner card (like the Hauppauge PVR-150) with an ordinary video card, and run the output via S-video to your TV, the picture quality will, at best, be about the same as a VHS tape. I started with a configuration like that, and was disappointed with the results. Cartoons, with their limited use of color and detail, looked fine, but live action scenes, especially if they involved hard-to-digitize video elements like smoke, looked lousy.

There are two ways to a better picture. One is to go with a higher-end video card that’s designed for gaming (specifically, an ATI or NVIDIA card). Most of the folks in the forums who were watching on a TV instead of a computer monitor used the S-video out on these cards. Some of the new cards apparently have a component out as well. Some used a VGA-to-component adapter (but you have to be careful not to blow up your TV!).

The other approach is to go with the Hauppauge PVR-350, which is a tuner card that has a hardware-based decoder and S-video out built-in. This is supposed to give the best possible picture, but there’s a major drawback: it will only output data that was processed through the tuner. That is, you can’t use it as a substitute for a video card (e.g. it won’t show your Windows desktop). The big breakthrough for this card came last year when the SageTV folks figured out how to run their TV scheduling video overlays through it, so you could at least see that much through your TV.

I currently have the PVR-150, which I’m going to give to Chris (as he hasn’t bought his TV tuner card yet, and that’s the one he wants). I’m going to get the PVR-350. Since I don’t want to have a computer monitor sitting next to the TV, I’m also going to get an S-video selector box. My TV only has one S-video input, so I can use the selector box to switch between the output from the TV tuner card and the output from the video card. I’ll probably only need access to the desktop every once and a while, so it should work out fine.

My main motivation for doing all this was to provide time-shifting and commercial-removal for the shows Kai watches. SageTV is really cool: you can easily search the TV schedule for a show (say, Sesame Street) and then tell it to record every new instance (i.e. so it won’t record a re-run if you’ve already recorded it), and then you can tell it to keep, say, the 10 most recent episodes on the hard drive, and to just delete older ones. And I’ll finally be able to keep up with The Daily Show! I’m putting Kai to bed when it’s on at 7, and I’m asleep when it’s on at 11. Since The Daily Show seems to have more than your average number of commercials, I bet I can watch an entire episodes in 15 minutes after skipping them.

The other cool thing is that you can hook up your VCR to it, so you can transfer your videotapes to DVD. We have some infant videos of Kai I’d like to digitize! And I guess it’s the only way I’ll ever see the non-Special Edition of Star Wars on DVD…