RoadKingMoe
04-15-2002, 03:44 PM
There's a lot of confusion over this copy-protection issue. Perhaps some of the things I've learned about it will help someone else. I don't have all the answers, and probably still have more questions than answers. I don't have any expertise or inside info. But here's what I've put together.
HDCP is an encryption protocol that can only be licensed for transmitting information between DVI connections. It wouldn't be used to encrypt OTA, satellite, or cable broadcasts. I'm led to believe a conditional access system, such as that currently used by cable and satellite providers, for authorizing, and encrypting and decrypting, premium and pay-per-view services, would continue to be used for broadcasts. This could also be implemented on OTA broadcasts, using the ATSC standard for terrestial broadcast of CAS. I don't know if the CAS system in use today or provided for by the ATSC has a flag that could be set to cause signals to be down converted on analog outputs.
More likely, I believe ALL signals going out the analog outputs of future STBs with DVI will be downconverted. This is just a guess on my part, not something I've read from some authority.
For example, the new upcoming Mits TVs will simultaneously output any HDTV signal they are displaying, as 480i on the S-VHS and composite outputs for analog recording (as well as continue to output it in HD over the Firewire/5C port for digital recording).
Obviously, the Mits TVs don't have a component video OUT, but the new STBs probably will. It would make more sense to me if all HD signals on the component output are down-converted to 540p X 960, since the average TV viewer or consumer TVs couldn't tell or show the difference between that and 1080i (the TV would report that it's receiving 1080i since the scan rates are the same). However, the rumors say that component output will be downgraded to the 480p of DVD.
HDCP is also not used on prerecorded D-VHS tapes (just between DVI interfaces). The MPAA has given support to JVCs proprietary D-Theater encryption for that. Although the current JVC D-VHS offers an analog component video output of HD recording, the D-Theater protocol has a flag that could be set in future videos to permit HD output only on digital outputs, such as DVI-HDCP and Firewire/5C. The next version of JVC's D-VHS machine "may have DVI" according to one of their spokespersons. I suspect that will be in addition to Firewire, since they'll still need that for input, and I suspect that it WILL happen, since many future TVs (except Mits) will have only DVI digital input, not Firewire.
DVI is strictly an interface for use between source boxes and a display. It would not be used to connect an STB to a D-VHS recorder. The JVC and Mits D-VHS use the only other industry-defined digital connection useable for that, which is Firewire (however, the Mits' D-VHS, including the new one coming, do not support JVC's D-Theater and will not be able to play pre-recorded D-Theater tapes).
A number of new STBs are on the horizon which will offer DVI-HDCP for connecting to a display, and Firewire/5C for connecting to a recorder. The MPEG2 they use over the Firewire (actually the one passed through from the CAS provider), can set the copy flag to copy never, copy once, or copy forever. Copy once would provide some "fair use" yet prevent copies being made from the one copy. And DVI would have no inherent bandwidth advantage over Firewire if the source material is already compressed with MPEG2.
At any rate, I wonder if the Mits TVs with Integrated tuners, which have the Firewire/5C capability (the same things the rumored "promise module" will provide for Mits' tunerless "HD-Upgradeable" models) will be able to use the recording output of the new STBs to view content in full-resolution without down-converting, even if the flag is set to "copy never." Remember, the MPAA is only concerned about full-digital quality video being pirated and getting out on the Internet (disregarding the amount of bandwidth that would require!) and they don't want to let it out on an unencrypted analog output. 5C provides protection of digital video, just as CAS and D-Theater do. It also helps that Mits' Robert Perry is one of the 3 co-chairs of the Broadcast Protection Discussion Group, who is coming up with all this.
Anyway, that's about as much as I can deduce from what's going on. If I'm wrong about something, I certainly don't mind correction, and will learn from it.
HDCP is an encryption protocol that can only be licensed for transmitting information between DVI connections. It wouldn't be used to encrypt OTA, satellite, or cable broadcasts. I'm led to believe a conditional access system, such as that currently used by cable and satellite providers, for authorizing, and encrypting and decrypting, premium and pay-per-view services, would continue to be used for broadcasts. This could also be implemented on OTA broadcasts, using the ATSC standard for terrestial broadcast of CAS. I don't know if the CAS system in use today or provided for by the ATSC has a flag that could be set to cause signals to be down converted on analog outputs.
More likely, I believe ALL signals going out the analog outputs of future STBs with DVI will be downconverted. This is just a guess on my part, not something I've read from some authority.
For example, the new upcoming Mits TVs will simultaneously output any HDTV signal they are displaying, as 480i on the S-VHS and composite outputs for analog recording (as well as continue to output it in HD over the Firewire/5C port for digital recording).
Obviously, the Mits TVs don't have a component video OUT, but the new STBs probably will. It would make more sense to me if all HD signals on the component output are down-converted to 540p X 960, since the average TV viewer or consumer TVs couldn't tell or show the difference between that and 1080i (the TV would report that it's receiving 1080i since the scan rates are the same). However, the rumors say that component output will be downgraded to the 480p of DVD.
HDCP is also not used on prerecorded D-VHS tapes (just between DVI interfaces). The MPAA has given support to JVCs proprietary D-Theater encryption for that. Although the current JVC D-VHS offers an analog component video output of HD recording, the D-Theater protocol has a flag that could be set in future videos to permit HD output only on digital outputs, such as DVI-HDCP and Firewire/5C. The next version of JVC's D-VHS machine "may have DVI" according to one of their spokespersons. I suspect that will be in addition to Firewire, since they'll still need that for input, and I suspect that it WILL happen, since many future TVs (except Mits) will have only DVI digital input, not Firewire.
DVI is strictly an interface for use between source boxes and a display. It would not be used to connect an STB to a D-VHS recorder. The JVC and Mits D-VHS use the only other industry-defined digital connection useable for that, which is Firewire (however, the Mits' D-VHS, including the new one coming, do not support JVC's D-Theater and will not be able to play pre-recorded D-Theater tapes).
A number of new STBs are on the horizon which will offer DVI-HDCP for connecting to a display, and Firewire/5C for connecting to a recorder. The MPEG2 they use over the Firewire (actually the one passed through from the CAS provider), can set the copy flag to copy never, copy once, or copy forever. Copy once would provide some "fair use" yet prevent copies being made from the one copy. And DVI would have no inherent bandwidth advantage over Firewire if the source material is already compressed with MPEG2.
At any rate, I wonder if the Mits TVs with Integrated tuners, which have the Firewire/5C capability (the same things the rumored "promise module" will provide for Mits' tunerless "HD-Upgradeable" models) will be able to use the recording output of the new STBs to view content in full-resolution without down-converting, even if the flag is set to "copy never." Remember, the MPAA is only concerned about full-digital quality video being pirated and getting out on the Internet (disregarding the amount of bandwidth that would require!) and they don't want to let it out on an unencrypted analog output. 5C provides protection of digital video, just as CAS and D-Theater do. It also helps that Mits' Robert Perry is one of the 3 co-chairs of the Broadcast Protection Discussion Group, who is coming up with all this.
Anyway, that's about as much as I can deduce from what's going on. If I'm wrong about something, I certainly don't mind correction, and will learn from it.
