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  • D-VHS: It had to happen....

    From http://www.wired.com/news/technology...,41045,00.html

    LAS VEGAS -- The DVD, which has plenty of problems already, could be dealt a further blow from a new format that comes in a package we're all familiar with: VHS tape.

    Now, with DVD bogged down in legal problems surrounding DeCSS and copy protection, and the failure of the industry to come to an agreement on a single standard for recording, JVC is hoping lightning will strike twice with its VHS format through a new Digital VHS, or D-VHS.

    JVC introduced the new D-VHS tape at the Consumer Electronics Show (CES) along with a high definition television (HDTV) set that protects high definition content from being copied. Video on D-VHS tapes is uncompressed, so it's enormous. A 75GB hard disk would only hold around 30 minutes of the video, according to company officials, making the trading of HD content over the Internet impossible.

    D-VHS can record and play back up to four hours of video in high definition mode -- up to 1,080 lines per screen width, or more than double the resolution of DVD, according to Allan Holland, national product specialist in the consumer video division at JVC. It can also record at the standard VHS resolution of 240 lines per screen width.

    JVC was originally the Victor Company, which developed the VHS format in the mid-1970s and was bought out by Japanese investors that renamed it Victor Company of Japan. It won a format war in the early 1980s with Sony's Betamax technology to become the de facto home video recording and playback standard.

    With twice the resolution of DVD and a high definition recording option, D-VHS could give DVD a major run for its money, since the recordable standard for DVD still isn't set and now DVD discs are vulnerable to piracy.

    D-VHS also has the benefit of full backwards compatibility with VHS tape. "You could have one piece in your stereo for everything with D-VHS," said Holland. "Of course, as the developers of VHS, I'd like to think we're going give DVD some major competition."

    A new Macrovision copy protection system prevents the duplication of tapes by copying from one digital deck to another. The content is encrypted with a High Definition Copy Protection (HDCP) system JVC developed that is similar in function to the Content Scrambling System (CSS) on a DVD.

    The HDCP system can't be broken, however, because only high definition sets will have the HDCP decoder, according to Dan McCarron, national product specialist in JVC's color TV division.

    JVC's high definition television set uses the Digital Video Interface (DVI) that Intel developed for PCs and high definition television sets. DVI ports on PCs will not have the HDCP decoder, so PCs can't be used to break HDCP like it did with CSS.

    So, with the combination of massive video size and the fact that HDCP decoders are only in high definition sets, McCarron thinks it has the answer to Hollywood's concerns over content protection.

    "One of the reasons Hollywood studios support this is because the video is uncompressed," McCarron said. "By compressing it, it's easier to transmit over the Internet because it's smaller. Because of its size when uncompressed, it's harder to trade or copy."

    JVC is mustering Hollywood support. Fox Home Video, Universal Pictures and New Line Cinema have already agreed to support D-VHS and JVC claims more are looking to jump on board.

    But don't declare your DVD player obsolete just yet. The JVC D-VHS deck, which should be available around May, will sell for approximately $2,000, while blank media will cost between $10 and $15. JVC's only TV to support HDCP is the D'Ahlia system, which will sell for a whopping $10,000 when it ships this summer.


  • #2
    There is another thing in favor of disk based technologies: random access to data.

    I've yet to see a tape that could do this in any reasonable timeframe and without it eventually adversely affecting the life of the media.

    Dr. Mordrid

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    • #3
      These have been around a couple years. We had a Panasonic model in my old office in '99.

      It was MPEG2 with IEEE1394 and analog connectors.

      Look around and you'll find Panasonic, JVC, Phillips and Hitachi have been making them for a while...
      Please visit http://spincycle.n3.net - My System: Celeron 300a(@450/2v),Abit BH6, 128mb RAM, Win98SE, Marvel G200TV, Diamond MX300, Maxtor DiamondMax Plus 20g system drive, DiamondMax Plus 40 capture drive, IBM 8g Deskstar program drive, Adaptec 2940UW SCSI, 9gb Barracuda UWSCSI video drive, Hitachi GD-2500 DVD-Rom, UltraPlex CD-Rom, Plexwriter CD-recorder, Viewsonic PT775, Soundworks 4.1 speakers

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      • #4
        Yes, you are right, but dont those all have some form of compression? According to this article, D-VHS doesn't use any.

        A related question, cyjo~: can you use your decks for server backup? I am looking for some some big storage.

        [This message has been edited by JerryH (edited 09 January 2001).]

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        • #5
          Honestly, I haven't figured out what they mean by no compression. Broadcast High-Def is compressed already. All the current D-VHS decks use MPEG2 compression, sometime at higher than DVD-spec bitrate. The problem is, if you could plug a DVD player into it and record, it would re-compress in MPEG2 and the MPEG2 is one-pass, as opposed to multi-pass (in addition to various other processing) to create commercial DVDs.

          No you can't back up anything, unless you want to re-compress it. Here's a link for the player from my old office...
          http://www.prodcat.panasonic.com/sho...?sku=PV-HD1000

          D-VHS decks, up til now, have basically been souped-up digital S-VHS deck with MPEG2 compression and digital input.

          JVC may be talking about a second (or third) generation product, or there may be incorrect reporting going on...?

          On JVC's C-Cube chip:
          http://www.users.freenetname.co.uk/~mcfc/100037.htm

          [This message has been edited by cjyo~ (edited 09 January 2001).]
          Please visit http://spincycle.n3.net - My System: Celeron 300a(@450/2v),Abit BH6, 128mb RAM, Win98SE, Marvel G200TV, Diamond MX300, Maxtor DiamondMax Plus 20g system drive, DiamondMax Plus 40 capture drive, IBM 8g Deskstar program drive, Adaptec 2940UW SCSI, 9gb Barracuda UWSCSI video drive, Hitachi GD-2500 DVD-Rom, UltraPlex CD-Rom, Plexwriter CD-recorder, Viewsonic PT775, Soundworks 4.1 speakers

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          • #6
            And if you need a HDTV to use the format then, duh, dead already. Or perhaps 5 or 10 years away from being mainstream by which time DVD will be de facto, much like audio CD is inferior to DVD audio, but how many audio only DVDs do you see?

            If they make a set-top decoder to pipe to a normal TV then, duh, analog output can be captured compressed and spread all over the internet.

            Marketing spin is always such a laugh.

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            • #7
              (sorry for the off-topic but I couldn't resist without posting a reply)
              Maybe I don't know how to count anymore but they said a 75GB HD holds 30 mins of video and DVHS can record 4 hours so...my question is..how the he** do they pur 600GB of data's
              onto a *tape* ??
              And: "The content is encrypted with a High Definition Copy Protection (HDCP) system JVC developed that is similar in function to the Content Scrambling System (CSS) on a DVD."....well that's exactly what CSS developers thought.
              People should just learn that no algorythm is unbreakable, given enough time, money and reason to break it.
              The fact they say that there won't be any piracy just because the uncompressed video is too huge really makes me laugh
              Who trades uncompressed audio cd's on the internet? Everyone just takes an audio cd and makes mp3's out of it and trades these ones.
              99.99% of the people out there can't hear a difference between the uncompressed cd and the 128Kbits/sec mp3 of the same song.
              It just means warez'ed DiVX ;-) movies will have a much higher quality source to encode from

              Luke

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              • #8
                Thanks for links, cjyo~.

                If one assumes 600 Gigs of data on a D-VHS tape, that's probably not to out of the question.

                In my hand, I hold a 4mm (.04 cm) data cartridge with a total length of 124 meters (12,400 cm). That comes to an effective area of 496 cm^2. the tape has a listed nominal capacity of 4.0 Gigabytes.

                Assuming a linear relationship of area to capacity, we have 4.0Gigs/496 cm^2, or .008 gig per square centimeter.

                Now a T-120 VHS tape is listed as 1/2 inch (12.65 cm) width and length of around 245 meters (24,500 cm), for a total area of....5 times 5....carry the 2....gets you 309,925 cm^2.

                At .008 gig / cm^2 multiplied by 309,925 cm^2 comes to 2,479.4 Gigs. That sure is a lot - I guess I did assume quite a bit here, though.

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                • #9
                  I've mis-typed number here before too.

                  4mm is 0.4 cm not 0.04 so your tape area is 4960 cm^2 making your density an order of magnitude lower which would mean ~250GB on a 2Hr VHS tape if the same density as 4mm DAT tape were used.

                  --wally.

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                  • #10
                    <font face="Verdana, Arial, Helvetica" size="2">Originally posted by matroxg200:

                    99.99% of the people out there can't hear a difference between the uncompressed cd and the 128Kbits/sec mp3 of the same song.

                    Luke
                    </font>

                    While you're correct on most things I think this number is too high.
                    I CAN hear the difference at 128KBps for many tracks, in some rare cases the aliasing esp. in the trebles is even noticeable at 160KBps. And I don't think I'm the only one out of 10000...
                    But we named the *dog* Indiana...
                    My System
                    2nd System (not for Windows lovers )
                    German ATI-forum

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                    • #11
                      Okay Indiana, perhaps not 99.99%...but what about 99.9%?

                      Consider the amount of people who connects their soundcard output to a 20$ pair of speakers (those usually sold as "200W PMPO" and the like )and not only the people who could hear this difference on a reference system.
                      Even if they could hear the diff. they will not, because of other limiting factors and also because they're not trained to.
                      If you know how a compression algorythm works, you know where to look for its weaknesses
                      Luke

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                      • #12
                        Sorry JerryH but your calculation is still 1 order of magnutude wrong

                        You said 1/2 inch= 12.65cm and that is wrong: 1/2 inch= 1.27cm
                        So... 0.0008GB/cm^2 * 31115 cm^2 (surface of a 120m VHS format tape) = more or less 25GB.

                        Now... from 25GB to 600GB there's a huge increase I would say.
                        Maybe they use some multi layered tape recording that I never heard about and this could explain the trick
                        Another questions comes to my mind though..why would data centers still use sophisticated multi-tape DAT units to make their backups if it was so easy to put 600GB on a VHS-like tape

                        Luke

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                        • #13
                          sheesh! how embarrassing to get two different decimal points out of place. dagburn metric system!!

                          everything happens in threes, so there's probably one more error in there!!

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