View Full Version : Conversion box.
Knight
09-17-2002, 03:35 PM
I purchased a DVD player a while ago and it had copy protection built in and would not work through a regular Co-Ax cable but Radioshack provided me with a little black box that would take my composite video input from my DVD player and it also had a Co-Ax in and out to put it in the loop with my TV.
why would there not be something similar that would accept the DVI input from your reciever or device, and output component/sound to your tv/AV reciever????
it seems to me that if they do this that would be the logical step and there is absolutely no reason for anyone to panic.
Video Stabilizers have been around for a long time. Not everyone knows about them. Not many people tape DVDs because of the loss in quality and the loss of DD5.1 (not a digital format - you lose resolution, quality, etc).
HD programming will be different - here, you'd be able to make a perfect copy in digital format.
Although, if enough people end up with enough of a problem due to this whole DVI-HDCP situation, I'm sure a black market device will be available, but it will be illegal.
JoeInBH
09-18-2002, 08:43 AM
To comply with the HDCP licensing agreement as it is now drafted, copy-protected material cannot be transmitted as an analog signal in a manner such that an ordinary person, using ordinary equipment could capture the signal.
It would be perfectly "legal" (in the sense of complying with the licensing agreement) for manufacturers to produce converters, but they would just have to be adequately secure. How the engineers will do this is speculation - there is currently no market for such converters. I haven't seen any HDCP encrypted material anywhere to date. So the only advantage of DVI vs. component today is arguably better picture quality, although the jury's definitely still out. Presumably that advantage would be lost by having a "converter." If (big if) and when there is actually a reason for people to own "converters" my guess is that it will require a hard-wired internal upgrade on your TV - but I'm pretty confident that will be available and legal if you're interested. As 57 said, most people might just find it easier and/or cheaper to use unlicensed external converters - although there's no incentive today for anyone to start producing those either.
Joe
Logansneo
09-19-2002, 02:22 PM
Here is a link to a site I recently ran across that makes a conversion box for just this purpose, although I am unsure as to how it would deal with the HDCP protection.
http://store.kayye.com/kayye/dvitovgacon.html
-Jeremy
JoeInBH
09-19-2002, 04:40 PM
You can buy cables that go DVI-component, by-passing VGA, for a lot less than that box. DVI-analog connectivity has been an issue for awhile in the front projector market, as many business applications will require outputting via a laptop or such, so it's not that the connection itself is a very hard one to make.
As per my email above, however, there's no reason anyone would want to do this to connect, for example, their STB to their HDTV. Any improved picture quality from the DVI (if any) is lost by the connection, and such connections do not address HDCP. Soup up such a box with some software and some hacked keys to decrypt the HDCP, and you've got 57's unlicenced converter. If they could be manufactured on a large scale, they'd be simpler and cheaper than the hardwired fixes manufacturers will develop, but if the manufacturer's have any sense, they'll fight the external converters. The "black market premium" that will accompany the risk associated with legal liability will probably make the licensed fixes cheaper. That's my hunch, but I guess we'll see how it all works out in 5 years if DVI/HDCP ever starts to take off.
Joe
Tesla
11-17-2002, 10:13 AM
Re: Conversion box
> So the only advantage of DVI vs. component today
> is arguably better picture quality ... -- JoeInBH
Does somebody really say DVI gives you better picture quality? Let's think about that.
The picture and sound come into your tuner in a highly compressed digital stream (using MPEG-2 compression) at 19.4 Mb/s. One way or another, this digital stream has to get uncompressed. After uncompression, you have the actual luminance signal and two color difference signals, still in digital form, at an extremely high data rate.
It's like unzipping a text file to get the original. Unzipping doesn't add "quality", it just undoes the compression.
The next thing that has to happen is these three very-high-data-rate digital streams have to go to three digital-to-analog converters, which produce the high-bandwidth analog signals known as high-definition YPbPr component video, which ultimately get transformed into the RGB signals that drive the RGB guns of your picture tube.
Whether your equipment uses DVI or doesn't use DVI, the same things have to happen. Exactly the same.
What's different is the location of the three digital-to-analog converters. They can be in your tuner, or they can be in your monitor.
Scenario 1: The three digital-to-analog converters are in your tuner. High-definition YPbPr component video comes out the back of your tuner, goes to your monitor, it all goes round and round, and everybody's happy.
Scenario 2: Your tuner nas no digital-to-analog converters. They're in your monitor. Your tuner uncompresses the MPEG-2 stream as usual, producing the actual luminance signal and two color difference signals, still in digital form. Which it sends out the back of the tuner on an interface called DVI, at the extremely high data rate of 5 Gb/s (gibabits/second). You pass the three data streams to the DVI input on your HD monitor. They go directly to the monitor's three digital-to-analog converters, which produce the high-bandwidth analog signals known as high-definition YPbPr component video deep inside an integrated circuit where you can't get your paws on them, and they ultimately get transformed into the RGB signals that drive the RGB guns of your picture tube. And everybody's happy.
But actually, everybody's not happy.
In Scenario 1, Hollywood's not happy. That's because you have access to the dreaded high-bandwidth analog signals known as high-definition YPbPr component video. An astute person could use that to make pristine copies of Hollywood's most valuable intellectual properties and swap them on the Internet.
In Scenario 2, Hollywood's happy but you're not. That's because you can't get your hands on a high-definition signal that you can record. You can't time-shift a high-definition program because there's no way you can record a 5 Gb/s DVI data stream. You can't pause a high-definition program if all you have to work with is DVI.
Next time you visit the electronic superstore down the street, tell 'em how impressed you are with all these DVI things. You'd really like to hand them a few thousand bucks and start hauling this stuff home. But say to the guy, "What do you have so I can time-shift or pause a high-definition program? I really have to have that! Not having that would kill the whole deal!"
Kindly do that in a half-dozen stores, and report back to this forum. It will make interesting reading.
What these DVI TVs do have on the back panel, as a consolation award (a booby prize), is a yellow RCA-type connector called "composite video out". The lowliest of the low. DVI TVs take 1080i and 720p high-definition signals and downconvert them to 480i (standard definition, the same as you've used all your life). They feed that wimpy thing out the composite video connector, which you can duly pass to your 15-year-old videocassette recorder. Now Hollywood can stop worrying about you and move on to other things.
That's what DVI is all about.
Hollywood has moved the D/A converters from the tuner to the display. Moving the converters cannot change the quality of the picture, but it can make darn sure you won't make any high-definition copies. That's what DVI does. A salesman who tells you otherwise is insulting your intelligence.
If you're content to put Hollywood in charge of your VCR, then throw up your hands, say I give up, and buy everything the salesman wants to sell you. Take it home and live happily ever after.
But maybe you're not quite ready to do that. Isn't there a way around this? The Supreme Court says you have the right to do time-shifting. It's legal. It's called "fair use". So what are your options?
Well, you could start hanging around with the folks who are building what some call HTPCs (Home Theater PCs). Sure, that's an oxymoron if there ever was one. But look at what they're doing.
Some of them get a black computer case that looks like a VCR, but twice as high, stick in a motherboard, and plug one or two ATSC tuners into the PCI bus. Some of them put the thing in the living room with the rest of their audio-video gear, connect a UHF antenna, and plug the high-definition YPbPr component video output into a high-definition television monitor at 1080i. Or into a nice computer monitor, like the Samsung SyncMaster 240T LCD HD Monitor.
Some of them have a hand-held remote control, and can pause and time-shift high-definition programs until the cows come home. With two tuners, they can record the MPEG-2 stream of say, the NBC digital television channel, while they watch or pause a program on the CBS digital channel. All in high definition, of course. The computer doesn't have to be very powerful to handle this, but you'd want a 120-GB hard disk. That'll record 12 hours of MPEG-2.
When I get this figured out, that's what I'm gonna do.
-- Tesla
Or you can wait a couple of months and get a high def PVR. The HDPVR will then output via component video or DVI/Firewire and you'll be happy. When/if encrypted signals start coming down the pipe, you'll only be able to watch and not record (or perhaps record only at a lower resolution). Those encrypted signals will likely only be on premium product.
Tesla
11-25-2002, 02:55 PM
Some PVRs:
http://www.hdtvoice.com/voice/showthread.php?s=&postid=7996#post7996
-- Tesla
TheBigE
11-26-2002, 09:14 AM
Originally posted by 57U
....When/if encrypted signals start coming down the pipe, you'll only be able to watch and not record (or perhaps record only at a lower resolution).
I wonder 57U...I truly think that the HD-PVR will be able to record the actual bitstream regardless of encryption, without downconverting. Now THIS is where HDCP will apply, in making a distributable copy of the PVR recording to some other device. But the wrinkle in my theory here is that some of these PVRs may also have internet capabilities, so some sort of protection would also have to apply to files that could be sent. Unless of course the internet distribution capability is ONLY between like devices. In this case the file would be transferred from PVR to PVR, and the recieving PVR would be in the same position as the original...unable to make a widely distributable copy.
maybe??
Originally posted by TheBigE I wonder 57U...I truly think that the HD-PVR will be able to record the actual bitstream regardless of encryption, without downconverting. You could be right. What I was trying to indicate (obviously not very well) was that there may be "issues" with recording and/or viewing encrypted material, if and when it arrives... All conjecture at this point.
