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What is SDI?

Discussion in 'Blu-ray & DVD Players & Recorders' started by robfitzp, Jan 18, 2003.

  1. robfitzp

    robfitzp
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    What is an SDI connection - is it superior to DVI?

    Cheers
    Rob.
     
  2. John Dawson

    John Dawson
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    Hi Rob,

    SDI stands for serial digital interface and is a single wire (coaxial)connection supporting interlaced video running at 270MHz. It is normally used in broadcast studios and the like.

    DVI stands for Digital Visual Interface and is a parallel connection using 4 twisted pairs (RGB and clock) running on a special connector. It can support a wide range of standards, well beyond XGA IIRC, but the minimum is 480p or 576p.

    Both of these have comparable quality but are not copy protected and are thus absolutely not allowed on DVD players, set top boxes etc. It is possible to get aftermarket mods with the usual caveats of invalidating the original warranty and so on.

    DVI does have a copy protected version, DVI/HDCP, and this is about to become legal for DVD players and STBs, indeed it is soon to be mandatory for US HDTV STBs. This will drive the market in a big way. However since the HDCP licence does not permit you to come out of digital back to analogue (even composite) video ever again you need a display equipped with a DVI/HDCP input. These are just starting to appear on the market but note displays equipped with DVI but without HDCP decryption are useless in this context.

    HDMI (High Definition Multimedia Interface) is mostly a superset of DVI/HDCP and also supports interlaced video, YUV colour space and audio (this year SPDIF, next year 8 x 192kHz/24 bit). Displays will incorporate this from late 2003. I predict this will be the worldwide standard in the future. For video purposes DVI/HDCP and HDMI will work together.

    Incidentally there are moves afoot in the world of copy protection to eliminate all analogue video interfaces on source components within say 5 years, with the exception of composite video. So IMO you should start to think very carefully if you are considering something like a new projector - make sure it has a DVI/HDCP input or can be retrofitted with one.

    HTH.

    John Dawson (Arcam)
     
  3. lmccauley

    lmccauley
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    Interesting stuff. Presumably DVD player manufacturers are looking seriously at DVI/HDCP or HDMI outputs for late 2003 onwards...

    Specifically (and I realise this is probably something you can't answer yet), when one or the other standards are ratified (by whoever needs to do it), will it be possible to add one of these outputs to a DV89 or DV27 player?

    Cheers,
    Liam
     
  4. rauer

    rauer
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  5. Nic Rhodes

    Nic Rhodes
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    :blush:

    Pity my original post is now number three!
     

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