Wednesday, December 2, 2009

MythTV - The Do-It-Yourself DVR

My television watching has decreased exponentially with every passing year. It wouldn't take much statistical analysis to determine a correlation (and probable causal relationship) between this trend and the additional children that have also arrived at Chez Lyons over the years.

I'm not complaining; it's two blessings in one. More tangible enrichment; less etheral mind candy. Still, it's nice to be able to pig out every now and again, and a DVR (or PVR) fits the bill nicely.

There are a lot of reasons not to rent a box from your cable company: the monthly cost, limited storage space, no user-upgradability, automatic deletion of programs (whether you've watched them or not), and the inability to back up your shows on external media (funny that VCRs should have a technical advantage in that respect).   Plus, if you want to have DVR access in additional rooms, you need to rent additional boxes.

TiVo is now also an option for Canadians, but the unit price is high, storage volume is low, expandability is nil, and the electronic programming guide costs are significant (details here).  EPG costs are a fact of life with any DVR, but with MythTV the charges are not for profit.  Currently I pay $20 US per year  for excellent service from Schedules Direct.  In comparison, TiVo charges $13 per month.

So what's so great about MythTV? What is MythTV? The website says:
MythTV is a Free Open Source software digital video recorder (DVR) project distributed under the terms of the GNU [General Public License]. It has been under heavy development since 2002, and now contains most features one would expect from a good DVR (and many new ones that you soon won't be able to live without).
They aren't lying.  Ever wish that your DVR would automatically skip all the commercials so you could easily watch your one hour program in 40 minutes?  MythTV does that, and once you get used to it, you'll find it a chore to watch someone else's DVR. And if you suddenly decide you want an additional unit in your bedroom, there's no extra expense.  Put the software on a moderately-powered computer that works as a "front end" -- sending commands and retrieving recorded content from your main recording box ("back end").

MythTV is actually much more than a DVR though.  In addition to its recording abilities, it can play audio, photo and video multimedia of any kind; display news and weather; download and play movie trailers; browse the Internet; emulate old-school video game platforms -- nearly any function that people can write a plugin for.  But for now, let's consider its use as a really great DVR.

Basic Hardware Requirements

I built my MythBox out of a slightly older PC.  If you know someone (or are someone) who buys a new system every two years, you may have access to the perfect hardware to start building with.  Alternately, you could buy a used PC, or a new one that just isn't state of the art anymore.  If you go with a new one, I'd recommend getting one from a dedicated computer store that sells their own line of no-frills, store-built boxes with no operating system installed.  There's no reason to pay for a copy of Windows that you'll just delete to install MythTV.

Use the best hardware you can acquire (or that you're willing to pay for).  For standard definition TV, a 3.0 MHz CPU (single core) would be adequate; if you'd like the capacity for high definition signals, go dual core.  AMD or Intel are equally fine, but steer clear of their cheap lines (like Sempron and Celeron, respectively).

Memory and hard disk space is very inexpensive these days, so there's no reason your box should have less than 2 GB memory and 1 TB of storage.  Again, don't buy these from big box consumer electronics stores; go to the same specialized, small box computer places that sell their own homemade boxes.  And to keep costs low, get OEM versions rather than retail boxed versions of hardware.

A MythBox needs a minimum of two video cards/devices: one display card and one video capture card/device/tuner.  If you intend to use your MythBox as a DVR, this may be all the hardware it ever needs.  If you want to use your Box to watch live TV while you record, additional capture devices will be needed (note: some external devices include more than one tuner, allowing them to record more than one program at a time).

Video Hardware

Your video display card should use the NVIDIA chipset.  ATI might work but I don't recommend it.  NVIDIA has provided very consistent support for accelerated video, and you want your box to work hassle free.

The MythTV wiki lists many video capture devices, with links to individual specifications. For a start, consider those on the following list.

*HDTV is tricky.  Cable companies don't really want you capturing their HD signal onto a box that you have full control over.  They use encryption to make their signals unusable, unless you use their equipment.  Fortunately, manufacturers are already finding ways around this.

Because it encodes analog HD output (via the component video outputs on cable or satellite TV boxes) the Hauppauge HD-PVR is currently the only way to record HD content from providers that encrypt their digital data streams. Don't be alarmed by sound of  "analog HD": everything I've heard indicates the difference in quality is negligible.  So unless you're one of those people who bought a Super Audio CD player, the HD-PVR 1212 looks like the first wave of the HD DVR future.

I elected go to the simple route: one tuner card and SDTV recording. I bought the Hauppauge (pronounced "hop-hog") PVR-150. It's no longer being manufactured, but I found one through a Canadian on-line retailer. Used ones are plentiful on eBay, and for much less.


MythTV is a software package that runs on (gasp!) Linux.  Do not panic.  You don't need to install Linux, or even really understand Linux, to use MythTV.  The simplest way to get going is to install a MythTV distribution that combines MythTV and the operating system in one disc.  It saves installation time, configuration, and disk space.  It gives you a highly specialized and streamlined system that does just MythTV, and does it well.  Best of all, it turns your old computer into an appliance; something you turn on and just use, without having to launch this and minimize that.  The DVR runs in full screen (although there's a graphical desktop you can get to, if need be).

Among the most popular ready-to-install distros are Mythbuntu (MythTV on Ubuntu Linux) and Mythdora (MythTV on Fedora Linux).  I've tried both and prefer Mythbuntu for it's leanness, plus a number of geeky technical preferences which you can safely ignore (unless you're suffering a bout of prolonged insomnia, in which case we should discuss these at length).

Further Investigation 

Do I have your attention?  A step-by-step installation is beyond the scope of this article, but there are a number of resources I recommend for more information:
  • The MythTVCast podcast -- great for learning during your commute to and from work.  Start from Episode 0, and listen to them in order.  The hosts (Pat & Dan) are immensely likable and the content is pure gold.
  • Video tutorials, including a Mythbuntu installation, also from the guys at MythTVCast.
  • The official MythTV wiki.
  • The official Mythbuntu support forum.
This is a short list by design.  Start here, then venture out onto Google and YouTube to learn more.