I have resonated with the notion of "Mac as a digital hub" since Apple started calling the phenomenon that back in 2001. Like many Mac (and, these days, Windows and Linux) users, my "digital hub" includes the usual cast of characters: my iPod, my digital camera, my digital camcorder, my printer, my scanner, and my cellphone.
Unlike most though, it also includes DVR capabilities using two products from Elgato Systems: the EyeHome and the EyeTV 500.
Here's a picture of the DVR portion of my "digital hub":
Using the EyeTV 500, I'm able to record "Over The Air" HDTV content to my PowerMac G5.
Back to the specifics of the EyeTV. Similar to TiVo, the EyeTV software lets you schedule what programs you want to record. The software also lets you play back the recorded content (and the hardware comes with a remote for this purpose). It also has an "edit" mode that you can use to remove chunks from the recording (so you can remove commercials). And it also lets you export your recorded (and, if you edited them, commercial free) TV to various video formats.
That's all nice and good, but I have no interest in watching recorded TV on my computer screen. A TV and a couch provide a much more enjoyable experience.
Here's where the EyeHome enters the picture. If you are thinking in TiVo-terms, the EyeTV is the "recording half" of a TiVo, and the EyeHome is the "playback half".
The EyeHome hardware connects to your TV (and/or stereo receiver) and then hooks up to your computer via your network. In addition to being able to playback video files from your computer, it can also show the photos you have in iPhoto and play the music you have in iTunes. I actually got my EyeHome before my EyeTV and used it just for the music playback capabilities.
I should probably also mention that although the EyeHome can play video directly recorded by most EyeTV models, but it can't play back the raw video files recorded by the EyeTV 500 (which is the HDTV EyeTV; the one that I have). The reason is that the video files are actually too big for the EyeHome to handle. The digital TV captured from over the air by the EyeTV 500 comes in at one of several resolutions, such as 480p, 720p, 1080i, etc. The EyeHome doesn't support playing video with a resolution greater than 480p.
That's actually OK by me because my TV, as much as I love it, isn't a HDTV. It has a "16:9 enhanced mode" which looks quite nice, but it's no HDTV.
The other reason I'm perfectly OK with the reduced resolution is that high resolution video takes up a lot of hard drive storage space. One hour of video captured by the EyeTV 500 can actually take up as much as about 8GB of space.
So what I do, to save space, and make the video sized OK for the EyeHome to play, is export the video from the EyeTV software as the MPEG Program Stream and then convert the video, using software called ffmpeg (those looking for a graphical program to use could check out ffmpegX), into the XviD format at either the resolution of 512x384 pixels (for 4:3 programs) or 592x392 pixels (for 16:9 programs). Those resolutions are actually below 480i (which is 640x480 for 4:3 content and 720x480 for 16:9 content), but again, since my TV isn't an HDTV, if the video was any higher resolution, I really wouldn't be able to tell a difference.
If I take one of those hour long programs that came in over the air at about 8GB in size, then remove the commercials (which makes the program around 42 minutes long), and then convert it to XviD at one of those resolutions, the resulting file trims down to about 425MB, almost 1/20th the original size. Not too shabby.
To provide plenty of space for my recorded TV, and so I don't have to run the EyeHome software on my G5, I copy over all the converted VxiD files to my old PowerMac G4, where I run the EyeHome software. Right now I have about 320GB of hard drive space in my old G4 dedicated to storing TV. That's about 700 hours of TV. :)
So, the end result is for the DVR-portion of my digital hub, I capture digital TV to my G5 using an EyeHome 500. There I remove the commercials, and covert the video files to the XviD format. Then I copy them over to my G4. And my EyeHome connects to G4 via my network and displays my commercial-free, high-quality (though not-quite-HDTV-quality) TV to me whenever I want in the comfort of my living room. Ahh, the digital life.