[mythtv-users] Was: 5C - DOH! Now: Set Top Box Passthrough/Converter Solution Device

Joe Borne joe.borne at gmail.com
Fri May 11 17:21:16 UTC 2007

> On 5/11/07, Joe Borne <joe.borne at gmail.com> wrote:
>> Well, my posting about the PYRO AV device really did stimulate
>> discussion.
>> I'm glad to see that.
>> Several people have contacted me off-list in order to offer help and
>> options in creating the device to translate DVI/HDMI/Component video
>> into a
>> usable ieee1394/mpeg2 signal. I have also opened discussions with a
>> couple
>> of hardware vendors.
>> In particular I intend to focus on the creation of an external box that
>> will translate several HD formats. Specifically we are looking to create
>> a
>> device that can accept DVI, HDMI, and Component video formats and output
>> them in VGA, Composite and ieee1394(via mpeg2). Only the ieee1394 output
>> would be HD (as of now). This combination seems to represent the best,
>> most
>> marketable product. Obviously the market just to solve the MythTV STB
>> problem is too small to persuade any vendor. So a device that translates
>> into multiple outputs would appeal to the broadest range of consumers.
> You call DVI, HDMI, and component video "formats" but they are really just
> transport mediums.  In no particular order, they can carry mpeg-2 and

>He's just talking about making a universal switchbox.

>The cost would probably outweigh the value.

>It's got to have he output hardware onboard because it's not
>attached to anything else. It's not a "card". More than anything
>else it looks like something akin to a macrovision descrambler.

>Something that could descramble encrypted HDMI and ATSC would be
>quite cool and rather useful and probably very illegal.

Well, not exactly accurate in either the case of cost or illegality. But
completely understandable assumptions.

Let me clarify...

The device in question would not be "universal" by any means, in that it
would only translate the HDMI/DVI digital video/audio signal to an mpeg2
stream. It would then output via ieee1394, or to an analog video signal and
stereo line out signal. As we already know, such a device already exists to
a degree with the PYRO AV. That device can accept an analog HD signal via
component video and output ieee1394 (in DV), composite video, VGA and stereo
line out.

The missing pieces are the DVI/HDMI input and the ability to convert the
signal to mpeg2.

According to an offline discussion, the technology for this to be done is
already in development. The solution would be a single chip costing less
than $10 per unit (I don't know the volume purchase requirement to get this
price yet). That communication is informal and unofficial as of right now so
I cannot disclose more about the component.

Now, considering the fact that the PYRO AV exists, and is able to do what it
does proves legality (IMHO, INAL). The device envisioned will not do any
descrambling of any kind. It simply accepts a clean, unencrypted video and
audio signal, translates it into mpeg2 and then carries the mpeg2 signal via
ieee1394 transport. It also translates this digital video signal into an SD
analog signal for VGA and composite outputs.

Since we are talking about intercepting the clean, unencrypted DVI or HDMI
signal AFTER the STB has descrambled it and is sending it to your
monitor/TV, we are not circumventing any laws. There are no laws preventing
anyone from converting a non-protected signal from one format to another for
purposes of viewing. If there were - then your cable box and every TV ever
made would be illegal, so would every switch box in existance

Now I know there's an effort underway to institute a handshaking key-pass
method for HDMI between devices such as DVRs, HD-DVD players and
televisions. My observations of the market, consumers and the behavior of
the manufacturers tells me this effort is doomed to fail. There is already a
proliferation of HDMI and HD capable devices on the market and in use that
will not be backwards compatible with said key-scheme. Said technology is
also going to be trivial to circumvent. Keys for the devices cannot be
rotated because access to the internet by the device would be needed - plus
any decent hacker could then connect to the device and give it the key he
wants. These keys will be published to the internet within days, if not
hours of release. Anyone want to talk about how long HD-DVD and Blue Ray's
so-called "uncrackable" key schemes lasted?

The entire effort to DRM-ify the portable media player market collapsed
under it's own weight because of the above factors, pressure from consumers,
and the desire of end-use device manufacturers to create a device that gives
their users what they want - total freedom.

So I'm betting HDMI encryption institution will fail. Even if it doesn't,
DVI and Component connections will be around for a very long time. Those
formats do not carry encryption and cannot ever carry it due to the fact
they are there to support the legacy devices that aren't HDMI-key
compatible. So our STB's are already outputting clean unencrypted signals.
We are simply talking about converting those signals from one format and
transport medium to another.

I don't want to sound boastful, but I've made a pretty decent living out of
predicting these types of trends and I've been right more often than not.
There are a lot of Linux servers and iPod's out there proving my point. The
market pressures and factors are already underway that will make the end of
encryption happen.

So let's move on from the stage of "You can't do that because..." and move
into "How do we make this happen?". That's how we got airplanes, phones, tv,
electricity, nuclear power, and basically anything worth having.

Now if I could just find cat-flavored dog food I could fulfill my dog's
dream as well.  :)


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