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Perfect Picture Path?

Discussion in 'Projectors, Screens & Video Processors' started by HouseofMu, Feb 21, 2002.

  1. HouseofMu

    HouseofMu
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    For those that know something about SDI.

    It's my understanding that a SDI connection would be the best possible when connecting a DVD to a Plasma screen. Now that the new Barco CineVersum specs indicate theres to be a SDI module, would this make it the ultimate connection setup for a DLP pj too?

    Would such a connection format negate the need for any additional processing (ie no ProgScan, Interlacers, anything...), including anything a HTPC could offer?

    Are there companies offering DVD player SDI conversions?

    thanks.

    n
     
  2. Jeff

    Jeff
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    Digital connections such as SDI or DVI allow comonents to be connected digitally so that the picture is not degraded by Digital to Analogue and Analogue to Digital conversions. While this does help a lot, it has nothing to do with video processing such as deinterlacing and scalling. An ideal setup would be somtehing like;

    DVD Player <SDI> Scaler/deinterlacer <DVI> Display

    Plasma Pan offer a Pioneer modded SDI DVD player for about £800


    Jeff
     
  3. HouseofMu

    HouseofMu
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    I see. So the CineVersum would still fall into that setup,

    DVD (using SDI) into Master control box (with video processing), converted into their own proprietry signal, onto the DLP head unit.

    Am I now right in thinking a SDI input signal, via video processing, would benifit a CRT pj also?

    Has anyone seen the output from a SDI moded DVD player, is it all its supposed to be?


    Do you think a HTPC could achieve comparable/better results?

    thanks.
     
  4. Nic Rhodes

    Nic Rhodes
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    Try this for more info in Digital Video Interfaces

    http://www.avforums.com/forums/showthread.php?threadid=13227&referrerid=7278

    My original post is now number three for some reason.

    Personally I am a fan of DVI over SDI as it can pass progressive scan signals, something SDI can't. It can also pass digital sound.

    There is also some good info over at Tag who are supporting DVI now. DVI is also the interface naturally on flat panel displays.

    SDI can produce some excellent results but is very much in the 'cottage industry hack' department as no big boys support it outside professional broadcasts.
     
  5. zcaps57

    zcaps57
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    I've read somewhere that you can mod Panasonic RP-91, and RP-56 and extract SDI signal straight from MPEG decoder.

    Most of DVD players should be able to be modded for SDI signal extraction from their MPEG decoder.

    My question is...
    how the hell do you feed the SDI signal to your display ??
     
  6. Nic Rhodes

    Nic Rhodes
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    Only some players can be modded. basically it is down to the MPEG chip set use. In my Tag it is all done in one chip and therefore SDI is a no no. The Pannys use several chip and the SDI signal need to be 'hikacked' of the PCB. Not the easiest thing to do. Panny and Pioneer are SDI happy in general. I suspect more and more people will be using a single chip solutions in the future.

    Re the display device (or scaler) then a similar situation exists and these need to be modded. Tjhis is expensive.

    To mod a SKY box cost £1500! The Panny mod from the states is much more affordable however.
     
  7. HouseofMu

    HouseofMu
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    Thats were the CineVersum Master, with its modular input slots comes into it, but as it converts from there into their own prop. signal, I'm unsure if its a benifit over other inputs, DVI/RGB etc, once this has happened.

    This is the only setup I've heard of where you can make use of a SDI signal into a pj.

    Is it possible to get DVI from a DVD player? or is this only available from a HTPC?

    If so does this means we can output SDI from DVD players but not input into pj. AND we have DVI inputs on pj that you can't get out of DVD players?

    More reading required: Nic, I'll follow your link, thanks.

    n.

    Found this on Wired about SDI conversions
     
  8. Nic Rhodes

    Nic Rhodes
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    SDI more typically goes into a scaler or de-interlacer. This does it biz and then outputs an analogue signal for the projector. The SDI signal is interlaced.

    The DVI signal can be just about anything (PS / interlaced etc) and can go to scaler and projectors / plasmas where these devices are designed to accept this digital feed. Hence DVI is suitable for DVD players, scaler, proectors and plasmas all on one interface. No A to D or D to A stages. It also does audio.

    Tag are now doing DVI on their DVD players. Others will follow shortly. It will become the norm for DVD player, just as it is for LCD monitors, PC graphics cards, plasmas and many panel projectors NOW.

    SDI is a great performer but it isn't the future but it is fun.

    Digital feed to a display really comes to the fore with digital display devices like plasmas and panel projectors, though there are advantage in leaving analogue conversions for CRTs to the very last minute.

    DVI is also the official digital interface for DVD Audio.
     
  9. zcaps57

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    As far as I know, DVI has maximum bandwidth of 1.65 Gb/s.
    What's SDI's ??
     
  10. Jeff

    Jeff
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    I don't think bandwidth limitations are really an issue for SDI since SDI is limited to non-HD video. I'm not sure that I understand SDI vs DVI debates. I see the two as having totally different applications even if there is a certain degree of overlap. I'm my case I use SDI as a means to get clean video into my PC so that it can then be deinterlaced and scaled. The next projector that I buy will have a DVI input so that I can extend the digital chain to the end point. SDI has been around for a very long time and will continue to be used in the future, but don't expect it to be used in mainstream consumer products. DVI on the other hand will.
     
  11. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    I have just finished an SDI - scaler - crt PROJECTOR installation down here....that's one of the reasons for my trip south.

    This was an SDI modded Pioneer737 to RockPlus with SDI in to an Electrohome Marquee. The final feed to the Marquee was by RGBHV. If TAW had managed to get their OpticalDVI output up and running we may have used that. I can say that looking at test patterns for resolution there is a marked improvement with SDI feed over component and a huge one over s-video.

    On realworld material tis translates to more detail and a greater sense of being drawn in to the image. I was pleased with end result!

    Gordon
     
  12. HouseofMu

    HouseofMu
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    Gordon, I thought DVI was only suitable for panel display devices, could you explain a little more about OpticalDVI going into a CRT pj.
    Is this a special type of DVI specific to the Rockplus and can other CRT's accept it?

    I'd (forum also I suppose) would be interested to know where/who modded/supplied the SDI player?

    Having read Nic's posting (and that Tag kit looks superb) about DVI, it does seem to be the logical choice. A widely adopted digital standard connection would be superb. Anybody heard any murmorings from other (ie cheaper) manufacturers proposing to include DVI?

    n.
     
  13. cskates

    cskates
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    A single DVI link's bandwidth is 165M pixels per second which is approx. 5Gbit. DVI supports two links in the same connector so you can have 330Mpps which is approx 10Gbit! A 1920x1080i signal needs less than half of a single DVI link...
    The disadvantage of the high bandwidth is cable length, only 5m at the maximum bandwidth, by dropping the bandwidth required you can increase the maximum cable length.

    The information I can find on SDI says it's only 270Mbit, with HD-SDI coming in at 1.45Gbit. The real problem with SDI is copy protection, or lack of it. Without copy protection in place most DVD and display manufacturers will not support it so it's likely to die out as a consumer connection before too long.
     
  14. Gordon @ Convergent AV

    Gordon @ Convergent AV
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    I bought SDI mod kit and had another of my customers (who is a dab hand at DVD mods) do the fitting. The mod kit came from Vigatec in Germany.

    More to follow

    Gordon
     

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