May 27, 2008 | By Danny O'Brien

Watching the Detectors

In the absence of NBC or Microsoft coming clean about what they've done -
what flags NBC sent, and what flags Microsoft obeys, we've been doing some detective
work of our own -- and we'd like your help.

NBC have already said that their activation of their copy-control system was
a "mistake". But when the next mistake occurs is the best chance to uncover what
copy-protection Vista obeys on digital, over-the-air TV.

We're looking to obtain raw data dumps of the ATSC stream next time your
copy of Vista chokes on an over-the-air digital TV feed.

(Note that we're not looking for "Can't Record Program" errors
with shows received via either CableCard units or analog TV tuners -- we know
that Microsoft obeys href="http://www.eff.org/deeplinks/2005/07/microsoft-sells-out-public-cgms">copy
controls on these systems. We just want cases where over-the-air, broadcast
digital (HD) TV has been affected.)

Right now, we're asking owners of the href="http://www.silicondust.com/wiki/products/hdhomerun">HDHomeRun to
watch out for this problem. We're concentrating on this device because many
Windows users run this hardware in conjunction with Vista Media Center, so
they'll be able to see when the problem arises. Also, it provides only digital
HD information to your PC (allowing us to eliminate any analog copy-protection
systems). Finally, it's relatively easy to make a complete copy of the digital
TV datastream using HDHomeRun's command line utility. Here's how:

  1. Go into Live TV mode in VMC and choose the problem NBC channel.

  2. Check the HDHomeRun LEDs to determine if tuner 0 or tuner 1 is

    being used. The LEDs are in this order: (Power) (Ethernet, Tuner 0, Tuner1).

  3. Record a 60 second sample of the stream:

    Open a cmd prompt and run:


    "C:\Program Files\Silicondust\HDHomeRun\hdhomerun_config" FFFFFFFF save
    /tuner0 sample.ts

    (specify tuner 1 if VMC is using tuner 1)

    Wait 60 seconds then press Ctrl-C to stop.

  4. When you've got your sample, mail EFF at info@eff.org with a specification of your setup, the date, time and channel of the show. We'll get in touch.

If you know how to record the raw datastream (not just the MPEG2 data, the
whole transport stream) on other hardware, let us know, and we'll add it to
this blog entry.


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