self, camphone, eye

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The immutable system engenders rot

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Mythbuntu Box Build (and Analog Copy Protection Blues)
self, camphone, eye
With a bit of time on my hands lately, I've embarked on a project that I've always wanted to try--I've built a MythTV box, using the excellent Mythbuntu distribution.

The Plan, of course, was to build a DVR box for analog cable because I don't feel like paying for the cable company's HD-DVR box. The recordings would be nice in HD, but theyr'e fine in standard-def, too, especially if I want to keep them around for when the HD set is in use--say, when the rest of the house wants to watch a football game I don't want to watch.

The house already receives HD cable via Cox Cable, but we have a bunch of cable drops still using analog cable with our older equipment. The HD box has put most of the analog equipment out of regular use, which is a pity, since it's pretty handy.

Back when I had money and time, I also bought an ancient Hauppauge WinTV Radio tuner card for just such a project. This uses a Conexant tuner chip, which is well-supported in Linux and a PCI interface. We had a bunch of old hardware kicking around the house, too, so old computers were cannibalized for parts.

Originally, I had meant to use an old HP desktop we had lying around, but its motherboard turned out to be cooked. So off I went to my local computer parts emporium where they had a sale on--buy an AMD processor, get the motherboard free--or, in my case for ten extra bucks.

In the end, I was only able to salvage the tuner card, a hard drive and a DVD drive. The rest--case, mobo, processor, graphics card, power supply--was new.

The build process was pretty standard: build it up, then, install the Ubuntu derivative of your choice. No drama.

The tuner card helpfully comes with a remote control, and it does work--sort of. I haven't yet been able to get all of the buttons working (although I seem to be onto something with this thread).

The biggest bug, though, is something I can't do. Certain programs can't be viewed or recorded at all--they show up as static. There is no signal-level problem as far as the CATV signal is concerned--otherwise the noise would be visible on all channels. This must be the dreaded broadcast flag in our midst.

For the record--I stumbled onto the programs by accident. I was flipping channels and found MTV turned into static. Apparently, they take a dim view of my watching or attempting to record Jersey Shore, which is fine by me, since I didn't intend to. But when I programmed the mythbuntu box to record Frontline on PBS, it came up as total static.

Anyway, initially, I thought this might be a problem with Cox setting the Copy Control Information (CCI) byte to "NEVER COPY." This shouldn't be the case--none of the channels were premium or pay-per-view. FCC regulations forbid cable operators from setting the byte to "never copy" for anything but premium services. [47 C.F.R. § 76.1904]

I called Cox to ask what was up. Was escalated to second-tier tech support and had a friendly conversation with with them. Apparently, Cox doesn't set any of the copy-protection themselves. I was directed to ask the originating stations about copy-protection problems.

After a bit more study, I concluded it couldn't be the CCI byte--that's for digital transmissions, and I'm only using an analog tuner. It must have been something else: analog copy protection. Like a vampire rising from its coffin, Macrovision's accursed copy-protection scheme has survived the transition to digital.

The copy-protection works by subtly varying the vertical-blanking interval of the NTSC analog signal. In the old days, this type of monkey business led to weird lighting and sometimes color bands on signals played back from videotapes. These days, it prevents my DVR from recording the program at all.

Now, even if I don't particularly like this, I can understand why certain programs are copy-protected in this way. I can't record The Adventures of Sherlock Holmes, for instance. But what really baffles me is why so many public-TV programs seem to be burdened by this restriction:

I mean, come on. I can understand dramas and the rest of it, but why on earth burden news an information progams like Frontline and NewsHour--especially when the programs are already available to view online? Indeed, why is it OK for Frontline World to distribute their show by video podcast, and then NOT OK for Frontline to allow viewers to record the show off their cable providers?


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