[mythtv-users] Time Warner & Firewire

[Lane Schwartz]

On 5/17/05, Brad Templeton <brad+myth at templetons.com> wrote:
> On Tue, May 17, 2005 at 11:21:30AM -0700, Mark Knecht wrote:
> > I happened to be at Comcast this morning getting a replacement remote
> > for my non-HD box. I managed to run into a fairly knowledgable tech
> > person while I was there. She said Comcast here in the Bay Area does
> > not enable 1394 by default on any box going to the field. If a
> > customer calls and asks for it to be turned on they ask what equipment
> > it's going to be attached to. Unless the answer is on a list of things
> > they support it won't be turned on. After that she says that even
> 
> Well, I think they are violating the FCC regs by saying this.  However,
> seems that you should be able to just tell them you have one of the
> TVs with a DTVLink (new name for 1394 in TVs) port.  My Mitsubishi
> 52725 has such ports, I know that Toshiba and some RCA TVs have them.
> Or perhaps one of the digital VCRs that have the ports.   I don't see
> a moral issue in lying to them if they are going to break the regs.
> 
> However, at least for now the hard truth is that the ability to get
> your HD -- or even your non-OTA SD -- over 1394 is likely to be a
> temporary situation, something flying under the radar until they notice
> it.   I can understand why they are leaving the 5C off at first.
> DRM systems can cause a great deal of user trouble and incompatibility
> even for people who have the blessed equipment.
> 
> But once a lot of people start using this, particularly if they find
> a lot of torrents sourced from people who got 1394 output of programs,
> then weenies at the studios will start calling the cable companies and
> forcing them to turn on the copy prevention and 5C stuff.
> 
> However, it's certainly great to have until that happens.  For now,
> tuner cards are legal again, but there's no clear path to the abliity
> of a Mythbox to record non-OTA HD shows in a way that will remain
> stable.  We're not too far away from people making cheap 720p capture
> equipment, in fact I think it could be done if people saw the market
> for it (which they will as consumers start demanding 720p camcorders,
> which won't need the A2D but will need the compressing chips).
> 
> Unfortunately, it will always be a kludge to convert digital to
> analog and then re-capture and re-compress/transcode it.  You will
> spend a lot to get (probably) larger recordings that are not as good.
> 
> Digital capture (DVI) would technically make it possible, if you compressed
> with exactly the same algorithms and parameters as the original source,
> to get approximately the same file out as came in, just with a lot of
> work.

Not that I would do this, nor recommend that others try.... :)

But how severe are the technical (not the legal) barriers to putting a
bus sniffer between the cable box and a blessed device, and observing
how the blessed device replies to the cable box's initial inquiries?

It's possible that the behavior of the cable box goes as follows:
notice that a device has been attached, make an initial query to see
if the attached device is blessed, if attached device is not blessed
then terminate connection, else if attached device is convinces the
cable box that it's blessed then send data to it.

Of course it's also possible that the cable box periodically queries
the attached device &/or actually encrypts the data.

Just some thoughts...

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