I want a HTPC. I've wanted one for a long time. Unfortunately I waited just long enough that HD content is now available from my cable company, so of course now I need an HD-HTPC (raising the price considerably).

Here's the challenge. Can you design a system capable of doing High Definition capture for less than $500? There are only two rules- all hardware has to be available online, even if it's from a local parts shop, and you can't use the results of an auction unless it's a "Buy it Now!" price. Delivery costs are not factored into the final cost.

Winner gets a big hug, and an invite to Google Talk if they want.

A few reference links:
PVRBlog
Building a MythTV box
Systm episode

Wait a month; the new Radeons being released in the begining of October are said to be able to decode H264 in hardware. Not sure if they'll be able to encode as well though.

What's H264?

I was thinking something along the lines of mythTV, this capture card, and one of their recommended nVidia cards (FX5200). What will the new Radeon capture cards do that this setup won't?

Well, unless I'm mistaken, that card does software encoding, NOT hardware encoding. It'll mean slower, and harder to do multiple things at once (such as watch one show, and record a second).

I may be mistaken, though.

What I found was that no card currently available was able to decode a digital cable signal. What that means is you can only record the channels you watch...

The best quality video that card will provide is Svideo I believe. While Svideo's not bad, it's not component so you'll probably lose a lot of the quality you'd be expecting from HD. I don't really think there's a card out right now that will provide good quality HD signal into an HTPC, but I've been wrong before~

P.S. on the subject of digital, you can use the cable box to decode the signal and then output the decoded signal to your HTPC. Obviously the more channels you want at the same time, the more boxes you need, but the HTPC can be used to control the external box which is a pretty good workaround with the state of the hardware right now.

Today's processors can decode 720p HD content, but I think only Apple's high end G5 dual processor setup is capable of reliably running 1080p content. Below is a picture of my processor usage (P4 2.8C) while playing the Batman Begins trailer in 720p from Apple's HD gallery:



For the majority of the trailer the processor usage is between 40 and 50%, spiking to 58% at its highest. Since 720p is less than half as demanding as 1080p, my processor would most likely be pegged at 100% and dropping frames for much of the trailer.

Here's an AnandTech preview of the next generation of ATi processors, and they state that even the RV515 (low end) will have some sort of H264 decoding (though that could just mean software decoding, so I'd wait for the actual reviews).

I'm interested in the RV530 series; 12 pipelines, low power consumption, and H264 decoding should make it a good all-round gaming/multimedia card that won't cost a bundle.

Edit: I just realized that because the Batman Begins trailer was only a 1280x544 widescreen, it wasn't as accurate an example as a true 1280x720 image. Here are a couple processor usage shots while running The Macaulay Library (1264x780) and the BBC Motion Gallery (1280x720). The yellow line represents 50% processor usage:

Macaulay Library:


BBC Motion Gallery:

Just as an update, AnandTech has an article up which talks about ATi's "Avivo" platform. Here's the first page of the article, and here's the page concerning GPU accelerated H264 decode.