Simon wrote:
On 2/20/07, James Richard Tyrer <[EMAIL PROTECTED]> wrote:
My was that if software running on the computer can turn off HDCP
for a video card that the card would not meet the requirements. If
software can't turn it off, then the software does not need to be
closed.
So, closed software is neither necessary nor sufficient to meet the
requirements. If that is the case, there is no reason that we
could not produce a board that could be licensed.
The license itself assumes the usage of closed software, and
prescribes the use of various techniques, such as code signing (this
is mandatory), to protect the code.
This appears to apply to the implementation of HDCP in software. This
would appear to be an obsolete provision since new chips implement it in
the HDMI transmitter chip.
If the software can't turn off the HDCP, that means more logic would
need to be implemented in hardware.
Not much actually. The video controller has registers indicating the
resolution of the screen and all the MCU needs to do is read these and
do a simple compare to turn HDCP on or off.
Plus, you have no way of allowing the software to signal whether
content is protected or not, and therefore must assume that all
content is protected.
Yes, I agree that this is bad. But, it appears that that is what may
happen with other hardware.
This is very contrary to the goals of OGP, but to do otherwise would
breach the terms of the license. So, there's still no way to
implement the scheme legally.
Yes, we could encrypt all HD video over HDMI. This would satisfy the
license terms as long as there was no way for software running on the
system to turn it off.
I don't know if these devices are legal but they appear to be made
under license. However those currently available strip HDCP off
of a HDMI or DVI signal so that it can be used with a monitor that
doesn't support it.
It's impossible that such devices are made under license, they defeat
the whole purpose of HDCP.
I agree. However the company -- http://www.spatz-tech.de/ -- making the
first one (now discontinued) clearly does have a license. IAC, there is
the the PRC (mainland China). I see no way for anyone to stop them from
making them and selling them mail order to the USA.
OTOH, I see no reason why a device that *adds* DHCP to an HDMI signal
that doesn't have it would not be legal and could be produced under the
license.
This results in a very strange situation. Clearly, it is perfectly
legal for us to offer a board with non-HDCP HDMI on it. However, if we
obtain a license, it would appear that this would no longer be legal.
Would this apply to all products we make or only to individual products.
E.G. could we offer one board with HDCP and one board without it?
There have been reports of TVs that won't accept a HD signal over
HDMI unless it is HDCP encoded. As I said previously, we need to
find out if this is true.
Indeed, but it's not our problem if it is, since there's nothing that
can be legally done, and in terms of cracking (illegal, but only in
the US and places with similarly strict DMCA-like laws), HDCP seems
to be already fully broken. Plus, we wouldn't want to attempt to
make an unlicensed implementation of it, because that would probably
make it impossible to sell an OGC in certain countries.
We do not want to crack this. If DHCP is needed, we should see if there
is a legal way to offer it. If there isn't a legal way to offer it,
then we should contact the EFF or some other legal foundation to see
what can be done since this would be a conspiracy in restraint of trade.
--
JRT
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