[mythtv-users] visit from the cable guy (Firewire query)

[Steven Adeff]

On Wed, Apr 2, 2008 at 1:52 PM, Steve Peters - Priority Electronics
<steve at priorityelectronics.com> wrote:
>
>  >The only way to store something on a hard-drive is to convert it to
>  >digital, so I'm not sure what you're asking about with regards to
>  >that.
>  >
>
>  The reason I wondered this one was because it seemed like if this is the
>  case, then the hd dvr's must have two tuners in them, one for digital
>  channels, and one for analog channels. Also, since they can record two
>  programs at once, they now have 4 tuners in them??? Seems like a waste.
>
>  -Steve

I know for the Motorola's at least (the DCT-6xxx and newer), the
hardware basic internal hardware is all the same. What changes is the
exact options. So they can have one or two "dual tuners" (capable of
digital and analog tuning). The device also has an mpeg conversion
chip to convert analog stations to an mpeg. The internal system is all
digital, whether you have the DVR or not, so the signal is immediately
converted then passed to the rest of the hardware for doing the
overlay, etc. I don't know if it has a single mpeg encoder chip
capable of handling two streams or if each tuner section has its own
mpeg chip, though I imagine that there is one chip per tuner (and
probably all part of the tuner module).

So yes, they convert analog channels to a digital stream (mpeg), they
have two tuners, but they are like the QAM tuners on PC cards in that
they can tune one digital or analog signal at a time.

So, for instance, I have two DCT6200's (non-DVR) connected to my
mythbackend machine via firewire and can capture all the remaining
analog channels this way. Of course, I also have three QAM tuners for
capturing OTA HD stations.

-- 
Steve
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