Why no DVD transports?

Discussion in 'Archived Threads 2001-2004' started by Rob Rodier, Aug 9, 2002.

  1. Rob Rodier

    Rob Rodier Supporting Actor

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    I know there are a few, and that the multichannel music is a good reason for onboard d/a. But I am suprised that more companies are not offering dedicated dvd video transports. Why do you think this is?

    -rob
     
  2. Max Knight

    Max Knight Supporting Actor

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    I may be wrong, but the majority of DVD players do not offer digital decoding other than a downmix to stereo. Would that make most DVD players in essence DVD video transports?
     
  3. Rob Rodier

    Rob Rodier Supporting Actor

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    By transport I mean no digital processing by d/a converters. (i.e no analog outs) The idea would be to cut out the d/a converters and spend the extra money on making the transport better. They would cater to enthusiasts like oursleves. I know that the d/a converters in my dvd player are never used. I go coaxial straight into my processor. I would imagine that most people in here do the same.

    -rob
     
  4. Ted Kim

    Ted Kim Stunt Coordinator

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    I imagine part of the reason is due to the whole economies of scale issue. By inclusion of the D/A stages and mass production, manufacturers are able to avoid the dual inventory problem that making separate transports and players would entail. Furthermore, the D/A chipsets are pretty inexpensive nowadays. I seriously doubt they would save much money considering how big the target market is for dedicated transports.

    Furthermore, on the basis of music, a one box solution is often best for the lowest jitter. Another possibly is that lip sync could be better handled onboard. Also I think part of the issue is that video machines such as VCR's and Laserdisk have always had audio capability. Even if its redundant in a DVD transport, people are conditioned to have audio directly available in their video playback systems.
     
  5. John Kotches

    John Kotches Cinematographer

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    Speaking strictly in audio terms:


    Proceed's PMDT has no analog output.
    Meridian's 598 and 800, with MHR Smartlink option has no analog outputs.
    Muse's Erato has no analog outputs.

    Regards,


    Regards,
     
  6. John Royster

    John Royster Screenwriter

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    Also isn't there that whole copyright gorilla forbidding the output of digital video?

    With digital video out you could possibly have a perfect copy of a DVD. Don't know though as I'm not aware of the details of DVD copy protection.
     
  7. John Kotches

    John Kotches Cinematographer

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    John,
    The answer is... "that depends".
    Are we sending out the MPEG data, or are we sending out the output of the video encoder?
    If its the MPEG data, copy protection is an issue. If it's the digital output of the video encoder, the bandwidth is stupid big. To give you an example, assume it's an anamorphic widescreen presentation, which we're going to display progressive scan. Size of the image is ~800*525 (overscan area), with 24bit pixel depth (8 for each of R/G/B) and 60 frames/second. This is 604,800,000 bits/second. You need to sustain 80MB/sec to record this datastream. Not practical in the near future for consumer grade gear. HDTV, that's worse by a good amount [​IMG]
    So, it depends on the output.
    Regards,
     

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