SDI modification: Anyone know about this stuff?

Discussion in 'Playback Devices' started by Vince Maskeeper, May 13, 2003.

  1. Vince Maskeeper

    Vince Maskeeper Lead Actor

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    I've considered making the next step in the quest for PQ to getting a SDI modded player and passing direct digital to a Holo3d card. But, I'm not overly versed in the world of the SDI mod, and wondered if anyone here had done it, or read about it- and could fill me in.

    Specifically:

    If the digital stream comes off the bt.656 bus, the MPEG decoder in the player is still used, correct? This stream is the 480i decompressed strem, it doesn't pass the data as MPEG format for conversion elsewhere?

    If it doesn't pass the MPEG data, I assume flagging for aspect ratio, and frame flags are not included-- so all deinterlacing has to be done via cadence detection in the scaling device, and automatic aspect ratio modes are not possible?

    I was thinking about getting the new DVD-2900 Denon player- but am wondering if this would be complete overkill since internal processing (Silicon Image/DVDO PureProgressive Engine) would not be used (??) passing straight off the bt.656.

    If going to a SDI output mod, what is important in a transport? What portions are used/not used, and what should you look for?

    -Vince
     
  2. Dzung Pham

    Dzung Pham Second Unit

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    Hi Vince, I am close to taking the plunge on SDI myself. As I understand it, you are correct regarding the fact that the 480i data is passed after the mpeg decoder. So the most important quality of the an SDI transport is to have a high quality mpeg decoder. This usually means no chroma bug, and minimal artifacts. The older Panasonics (RP-91, RP-82, XP30, XP50) are generally regarded as having the best mpeg decoders. The Denon DVD-1600 also uses the same decoder (the part numbers are all listed on the Secrets Shootout). I don't believe the newer Panasonics that use an all-in-one design can even be modified for SDI since the digital mpeg decoded output is not available to be tapped into. I'm not sure about the Denon DVD-2900 because it uses a new decoder and Secrets hasn't reviewed it yet. In addition, I don't believe an SDI mod for the 2900 is available yet.

    I am not sure about the automatic ratio flags, but I do believe that it is probably possible to detect aspect ratio without using the flags. And even if it isn't, it's a simple button press to toggle through aspect ratio modes. I also know that many dvds that are 4:3 letterbox do not have the aspect ratio flag set correctly anyways.

    Regarding getting an overkill player, my thinking is that I would still like to get a player with good deinterlacing because 1) on lazy days when you don't feel like turning on your scaling device, you will still get good output, and 2) if you ever upgrade your player and move it to a different system, you'll get more use out of the player even if you don't use the SDI output.
     
  3. Greg Conti

    Greg Conti Stunt Coordinator

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    A high quality MPEG decoder that can be tapped is pretty much what you need. Alot of players now have integrated MPEG decoders/deinterlacers/DAs so there is nothing to tap. I went with a XP30 with a Silk100 running Dscaler. Comparing SDI with the component outputs of the XP30 and my HTPC running TT, SDI/Dscaler is a significant step up to my eyes. I would like to compare the Halo with DScaler.
     

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