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Discussion Starter #1
(This is all from a correspondance with someone close to the DVI/HDCP development that I had a few months ago, so feel free to cite more recent sources that contradict it).


The most important part: DVI/HDCP is only used as a connection between a source and a display device. Only display devices will have DVI/HDCP inputs. STBs, PVRs and HD-VCRs will not have DVI/HDCP inputs. The data on a HD-DVD, or a HD-VCR, or a HD-PVR is not HDCP-encrypted, so the restrictions on full 720p/1080i analog output don't apply to these devices.


The downscaling restriction only applies to the conversion of a HDCP to an unencrypted analog stream -- which none of these devices are doing. They're getting a compressed data stream off the HD-DVD (or from the cable company, etc), HDCP encrypting it themselves, and then sending that through the DVI connection. They're free to take the cable stream and convert that to full-resolution 720p/1080i, because it never was an HDCP stream.


DVI/HDCP is a restriction on the interconnect, not the source stream.

 

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But what about the ability of the IP owner to down-res the analog HD outputs that must be used to feed HD to every HD display sold to date? This is the main sticking point with most of us here.


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Discussion Starter #3
What about it? Sure, the content provider can down-res the analog outputs -- as they've always been able to -- but my point is that doesn't have anything to do with HDCP or the HDCP license, because that stream was never HDCP in the first place.
 

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Chris, I guess the fear is that now with DVI/HDCP, the cable company or DIRECTV or whatever will be more likely to downconvert their most compelling content thru the analog outputs than they would have been had they not included DVI connections. Sure, they have always had that ability but haven't chosen to use it up to now.


I guess I am still confused.


If a STB sends an uncompressed bitstream to an HD-VCR, why would the cable or sat company allow the VCR to create a full 1080I or 720P source to send over analog component to my display? It seems to me they would only allow an HD-VCR to receive the bitstream from the STB if it, too, was able to downconvert as well. Now, if I bought an HD-VCR tape and played it, I agree that could be full HDTV, but not recorded stuff. Correct?


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Rich Peterson

DBS Consumer Guide Author
 

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Discussion Starter #5
Quote:
Chris, I guess the fear is that now with DVI/HDCP, the cable company or DIRECTV or whatever will be more likely to downconvert their most compelling content thru the analog outputs than they would have been had they not included DVI connections.
That's true, though it's really separate from the DVI/HDCP connector issue. We should definitely lobby the cable companies to provide a full-resolution analog HD output on their STBs.

Quote:
If a STB sends an uncompressed bitstream to an HD-VCR, why would the cable or sat company allow the VCR to create a full 1080I or 720P source to send over analog component to my display?
I guess I'm not sure why they wouldn't allow that -- connections between a STB and a HD-VCR won't be DVI/HDCP, so that license agreement won't affect the HD-VCR's ability to provide full-res analog HD outputs.


Now, if there's going to be a digial interconnect between the STB and the HD-VCR (which there surely will be), that's going to need to be encrypted somehow. As will, I'm sure, the digital cable line or the content on a HD-DVD.


So what will really matter is what the license agreement of that encryption algorithm/connector allows. But it won't be DVI/HDCP, because that's only used between a display device and a source device (plus, it's uncompressed, which won't be the case for HD-DVD or cable content).
 

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Quote:
Originally posted by Chris Carollo:
The most important part: DVI/HDCP is only used as a connection between a source and a display device. Only display devices will have DVI/HDCP inputs. STBs, PVRs and HD-VCRs will not have DVI/HDCP inputs. The data on a HD-DVD, or a HD-VCR, or a HD-PVR is not HDCP-encrypted, so the restrictions on full 720p/1080i analog output don't apply to these devices.
I see no reason why a digital recording device would not record just the bit stream if its encrypted or not.


If it does not have a 5C input, then it would not be able to record encrypted HDTV, so having an analog HDTV output is no help. It would just be able to output HDTV that was never encrypted. That may be almost zero percent of the HDTV content.


If the video is not stored encrypted on a future HD-DVD, that might imply there will be no HD-DVD. Since no HD-DVD standard is in the stores, there is nothing to stop them from requiring encrypted HD-DVD.


Its difficult to believe that they go to all the trouble of encrypting video in multiple places and just put the bits out on HD-DVD for anyone to easily copy.
 

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I think it is true that neither 5C or HDCP explicitly limits what a cable or satellite box can put out, at least if they are treated as a source device. That is left to whatever agreement is between them, the box builders, and the content providers.


The problem is, we know it will be something, and except for 480i and encrypted digital they won't tell us what.


Since this has been going on for years they probably have a good idea what they are converging on but it is still impossible to get a definite answer.


So the completely unanswered question is "What, if anything, will emerge from component outputs on the back of a cable or satellite box?".


Nobody's telling.


- Tom


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Quote:
Originally posted by trbarry:
I think it is true that neither 5C or HDCP explicitly limits what a cable or satellite box can put out, at least if they are treated as a source device. That is left to whatever agreement is between them, the box builders, and the content providers.


The problem is, we know it will be something, and except for 480i and encrypted digital they won't tell us what.


This is where DRM (digital rights management) comes in. They'll have control over how many programs can be recorded and stored, which programs can't be recorded, stored for how long, etc. Of course, this requires getting rid of all analog data.


We're in the process of adding DVI/HDCP to our products, so perhaps I can find out what's required.


The content providers aren't about to cut a deal with each box builder individually -- too many of them. Plus, there are a limited number of chip and software suppliers the box builders can use, so they all end up being pretty much the same.




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-- Keith Jack

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"The data on a HD-DVD, or a HD-VCR, or a HD-PVR is not HDCP-encrypted, so the restrictions on full 720p/1080i analog output don't apply to these devices."


Correct. But none of these devices yet exist, and while they are not HDCP encrypted, they will be encrypted by 5C.


DVI/HDCP specifically applies to displays and STBs. In such a case, the HDCP license agreement specifically prohibits analog decrypted output of the encrypted bitstream.



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Due out this fall: A cable box with DVI/HDCP option:
http://www.scientificatlanta.com/vid...r%5F3100hd.htm


The DTCP license agreement (at least the one that was pulled from the website) requires that the stb not output hdtv analogue output on "protected" material.


Also to clairfy, firewire (not DVI) is supposed to be used for recording. The firewire/dtcp spec is encrypted compressed data. The DVI/ HDCP is encrypted uncompressed data.


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Alex
 

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Discussion Starter #11
Quote:
Originally posted by dkeller_NC:
DVI/HDCP specifically applies to displays and STBs. In such a case, the HDCP license agreement specifically prohibits analog decrypted output of the encrypted bitstream.
But that's my point -- that's not true. The HDCP license prohibits decryption of an HDCP stream, but because the stream coming into the STB isn't HDCP encrypted, it doesn't apply. The STB is free to output in whatever format it wants.


That portion of the HDCP license just prohibits people making digital-to-analog interconnects.


Anyone have a link to the DTCP license agreement? Since that's a compressed stream, it seems more likely that it will be used as inputs on these devices. If so, it's license agreement is the one we should be fighting, not HDCP.
 

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Chris:


I have to disgaree with you. Unfortunately, the dtcp (ie 5c/firewire) license agreement was pulled from their website, but it barred the licensed device from outputting hi res analogue.


I haven't read the relevant license agreement for dvi/hdcp. Do you have access to a copy?


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Alex
 

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I agree, it is the license, not the encryption, which is the issue. IMHO the difference is semantic.


BTW, what I did pull from the license agreement:


Quote:
4.2 Analog Outputs, Video. A Licensed Product shall not pass any analog representation or conversion of the video portion of Decrypted DT Data to any output except:

4.2.1 Where an Analog Protection System (“APSâ€) would not be or is not required to be activated according to these Compliance Rules as specified, or

4.2.2 Where such output embodies an approved analog Reprotection referenced in Section 4.3 of this Exhibit B, Part 1, which is invoked as specified by its copy control bits upon such output, or

4.2.3 Where the Licensed Product is a Computer Product and such output constitutes an output to a computer monitor, such as SVGA. (Adopter is cautioned that one or more protection methods are anticipated to be adopted for such outputs, which methods will become a condition of this Agreement or an amendment thereto.)

4.3 Analog Video Reprotection. In any transmission through an NTSC, YUV, SECAM, PAL, or consumer RGB format analog output..
Section 4.3 pertains to sdtv signals


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Alex


[This message has been edited by work permit (edited 07-27-2001).]
 

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I don't see what's to fight about. STB's will have a DVI port for connection to the Display device. It will be encrypted with HDCP. It may have a Firewire (AKA iLink,IEEE1394) port for recording. If the program provider allows copying you will use this port to record. The DVI port plays no role in recording. Any analog ports will be eather disabled or downgraded.


It's just that simple.


Todd


[This message has been edited by ToddD (edited 07-27-2001).]
 

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ToDD


Yup. Just to add, if copy protection is not enabled, then analogue DHTV will be passed through.


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Alex
 

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let me see? as long as i,m not recording mywidescreen tv is safe?


I HOPE


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tom
 

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Quote:
So the completely unanswered question is "What, if anything, will emerge from component outputs on the back of a cable or satellite box?".
kjack replied
Quote:
We're in the process of adding DVI/HDCP to our products, so perhaps I can find out what's required.
Keith -


If you could really (definitively) answer my question above I would be forever indebted, but also very very surprised. http://www.avsforum.com/ubb/wink.gif


- Tom



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Quote:
Originally posted by trbarry:
Keith -


If you could really (definitively) answer my question above I would be forever indebted, but also very very surprised. http://www.avsforum.com/ubb/wink.gif
Hmmm...then I guess either the license tells me to keep my mouth shut, it's so confusing I'll get even more gray hair, or there is no definitive answer... http://www.avsforum.com/ubb/smile.gif




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-- Keith Jack

author: Video Demystified
 

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I have a quick question for you experts.


I'm thinking of buying the new JVC "D'Ahlia" rear projector, which has the DVI/HDCP connection.


If some device had a DVI output, but not HDCP, are DVI/HDCP compliant devices supposed to be able to display the content? In other words, does the content have too be HDCP encrypted to be displayed, or does the standard support content "in the clear"?


Thanks!


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Mike Kobb

(Formerly "ReplayMike", but no longer affiliated with the company; these opinions are mine alone.)
 
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