Build Your Own Personal Video Recorder 101: (Part2)

ABSTRACT: I want to build a PVR, uh how do I go about doing that again?

Author: rampy AT randomdrivel.com



I want to build my own PVR what do I need?
A little bit of money, some patience, a little PC building knowledge, and a dream!



A brief word about costs: Your costs are directly tied to how fancy you want to make your PVR and what functionality you *have* to have. Your homebrew PVR expectations could be very low/simple like: "I want to grab some of my favorite shows and either watch them on my PC monitor or burn them on to DVD or SVCD for prosperity". In such a scenario you can simply buy a tuner/capture (ranging from $50 – $200) and you can use your existing PC as your PVR. Baddaboom Baddabing, done… but if you have higher expectations for your project such as having a small form factor PC and a sexy case that fits right in with your other entertainment center electronic devices, you are going to pay a slight premium and ratchet the costs up. The main point here is that your PVR costs correlate to your desired functionality and vanity.



Skillsetwise you should probably be comfortable upgrading your PC as you are going to need to be able to insert a PCI tuner/capture card. It doesn’t hurt to be able to build a PC from scratch (it’s not that hard if you done it before). You should also have a reasonable working knowledge of the OS (Operating System — but if you didn’t know what an "OS" is, don not pass go, do NOT collect 200 dollars, and go to circuit city and buy a Tivo instead) you are basing your PVR on. You should also be able to understand basic home electronic signal chain concepts like "coax in" and "video out" and "s-video". If you’ve got a grasp of all those concepts lets move on, shall we?



One last prerequisite: You probably should enjoy tinkering. The homebrew tivo is still in it’s infancy and it’s not necessarily a plug and play experience (but it’s getting close!). So if you do NOT like fiddling under the hood (so to speak) of your PC this might not be the best project for you.



Still with me? What hardware do I need?

That’s an excellent question. As you may or may not realize encoding video (encoding is the process of converting the analog video signal to a digital one) is a fairly processor intensive task. Decoding the recorded video also requires some CPU muscle. If you want to record one show while watching a different pre-recorded program concurrently, obviously that would also require significant horsepower. Thanks to Moore’s law and our fine friends at AMD, Intel, & VIA (in no particular order) almost any "modern" and properly configured PC can handle the load, for the most part.

Some other general thoughts — Don’t skimp on RAM get at least 512MB. You wouldn’t want to lose precious frames of "Baywatch" just because your hard disk is thrashing around with virtual swap memory. Speaking of hard disks: Get a nice big one with decent seek times and spindle RPMs. Although probably anything you go out and buy on sale at a big brick and mortar should be plenty fast enough.



The geekier of you may say, "*snort* Tivo is only running *snort* a 33mhz processor… why do I need such a beefy machine *snort*" That’s a very excellent way to segue to: "The miracle of hardware assisted encoding and decoding" A Tivo can easily record and playback your video streams because it has a special chip dedicated to encoding the incoming video (and decoding the outgoing video) streams thereby alleviating most of the pressure on it’s paltry 33mhz CPU.



This is why we STRONGLY recommend a TV tuner/capture card with hardware assist MPEG2 encoding. You can buy a cheapo TV tuner card and use software encoding which relies totally on your CPU to do the heavy lifting, but you better have a reasonably fast machine and even then I wouldn’t recommend it.



I’m sure people have had success building their own PVR’s with ATI All in Wonder or TV/PVR tuner cards (especially with Digital TV), but right now the "best" cards to do TV tuning with built in MPEG2 encoding is Hauppauge‘s WinTV PVR 250/350 line of cards (gratuitous Amazon Associates link). If a cheaper card came to market that was as good AND had MPEG2 encoding I’d be all over it, but right now Hauppauge is where it is at for homebrew PVR applications (actually those gateway Media Center convergence devices are just PC’s with a WinTv PVR250 MCE card in it and Windows Media Center Edition installed). planetjay explains his affinity for the WinTVPVR 250 vs other alternatives pretty well in an older byopvr forum post. I have an in-depth review of the PVR350 (also HTPCForums has a good review of the PVR250). A PVR250 will run your around 130 bucks, a PVR350 will run your closer to 180. (The WinTV PVR350 has an additional MPEG2 decoder for its TV out and a FM tuner. The PVR250 does NOT have a TV out NOR MPEG2 decoder NOR any FM capabilities. Both cards have the coveted MPEG2 encoding hardware).



The other main consideration when choosing a TV tuner/capture card is software/driver support. The WinTV PVR 250 is well supported by both LINUX and Windows based software solutions. From free solutions like MythTV (linux based) to pay for solutions like the well regarded Snapstream BeyondTV (TechTV review) or SageTV.

The Hauppauge WinTV PVR 350 hardware encoding is supported on the same level as the pvr250(it’s the same chipset really) BUT there is a caveat regarding the display of menus/OSD through the TV out on the 350. This functionality is NOT quite totally supported across the board yet (only CVS versions of MythTV with special IVTV/xfree86 patch (linux) driver, Beta GB-PVR (windows), and Beta SageTV) support displaying OSD/desktop through the PVR 350’s tv out ) To clarify, the TV out on the PVR 350 works fine with all software but it will ONLY show the source material, you will not see the on screen displays (OSD) or menus or your desktop… which makes it hard to interact with you PVR if you can’t see the menus. I know that seems like a lot of information but if you are considering the 350 (and I would consider) that’s an important consideration.



I don’t have an ATI All in Wonder or other TV specialized ATI cards, but BYOPVR-er valiamarkais notes that linux drivers/PVR software for their TV tuner/capture cards are lacking a bit,"
You might want to indicate the problems with drivers for the ATI all-in-wonder cards. These are very common fairly cheap video/tuner cards, and a lot of people have gotten burned when they found out it didn’t work with Linux. That’s the only addition I would include. I know there are some people who are working on drivers, but the progress has been slow (unlike the ivtv project).
" Those of you interested in the linux platform with ATI AIW cards might want to watch the Gatos Project



Lets move on to my other favorite topic: mini-itx. Mini-itx is a tiny form factor making it perfect for fitting a PVR in a small space or using a sexier case than the old stand by giant beige PC tower case. There are other options for small form factor PC’s like Shuttle systems (flex-atx – XPC), micro-atx, etc… and as long as you can fit a full sized PCI card in your slot you should be fine.



EPIA VIA has come up with a line of mini-itx board called the M-Series, presumably short for Multimedia ready. They are modestly fast processors (only 1ghz or less) BUT they have a built in MPEG2 decoder which means that you can use these comparatively (to intel/amd) slower CPU motherboards and still watch DVD’s and playback your MPEG recording without making the lil CPU sweat too much.



To recap: the attraction to the mini-itx EPIA VIA M10000 is:

A. the small size

B. the built in MPEG2 decoder

C. the small size





Hopefully a bell went off in your head… if not… wait for it. Ok I don’t have all day =). There potentially could be a great match between the WinTV PVR 250 with it’s built in MPEG2 encoding AND a VIA EPIA M10000 with its TV out and built in MPEG2 decoding. The only fly in the ointment might be trying to find the "best" drivers for your EPIA VIA M10000 ( official driver page | unofficial/beta/other drivers ) board to take full advantage of the MPEG2 decoding and tweak the TV out so that it doesn’t overscan (Note: the PVR 350’s TV out quality wise is superior to that of the built in TV out of the M10000 so if you are a quality junkie you may want to consider that — or possibly get a separate TV out card (like an ATI) for the m10000 if you decide to go that route)



If you want to get a good feel for what other people are using in their homebuilt PVR/HTPC systems you should check out the PVR hardware database (you’ll see a lot of mini-itx boards and hauppauge cards as well as some ATI tuner cards).



NEXT UP — SOFTWARE (in Part III of course!)