DVD Player W/Out The Layer Change?

Discussion in 'Archived Threads 2001-2004' started by John H Ross, Apr 20, 2002.

  1. John H Ross

    John H Ross Screenwriter

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    Isn't about time that somebody created a DVD player that, like most DVD-ROM drives, has a read-ahead buffer capable of *completely* hiding the layer change?

    I have a Sony DVP-7700 and, while the layer transition is reasonably smooth, it usually takes my Yamaha amp (Model DSP-A1) a second to re-locate the selected soundtrack. This can result is missing dialogue, etc, immediately after the layer change.

    DVD has been around for five years now. There have been tremendous improvements in picture and sound. But there's still a break in the movie and, as DVD-ROM drives have proven, this doesn't have to be the case.

    Are there any improvements on the horizon?

    John
     
  2. Alex Prosak

    Alex Prosak Supporting Actor

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    There are two players on the market that I know of that have memory buffers to help with the layer change problem and both are Denons. The DVD-2800 and the DVD-1600. I'm sure their new top of the line player has it too.

    I do completely agree with you that many more manufacturers need to incorporate this technology, layer changes suck.
     
  3. Leon Liew

    Leon Liew Stunt Coordinator

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    So far have not experienced any interruption on dialoque

    due to layer change. Mostlayer changes are slated during

    stationary scenes or when dialoque are completed and its

    only a few seconds for the amp to come back on.

    Well until they improve on this aspect,guess we will have

    to live it with for a while.
     
  4. John Kotches

    John Kotches Cinematographer

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    John,

    I don't know where you've been, but we (Secrets of Home Theater & High Fidelity) have been pointing out a number of drives that have gone over to using DVD-ROM drives as their mechanisms. Some of them include:

    Meridian 800 and 596, Panasonic RP-91, Apex (forget the models), Denon 2800.

    There are undoubtedly others, and if you read some of the other discussions that have been had on this topic you'd find lots of interesting information out there.

    This includes the fact that the overwhelming majority of discs are coded for a non-seamless layer break.

    Regards,
     
  5. John Cain

    John Cain Second Unit

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    So, the RP91 has a good layer change too??

    Cool...

    -- John
     
  6. Ian Montgomerie

    Ian Montgomerie Stunt Coordinator

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    The reason "DVD-ROM drives" (ATAPI drives) typically make the layer change really fast is that the drive will internally read ahead of where you have actually requested to read the data, and cache a lot of it. DVD player specific drives, such as those based on the UDE specification, also cache data. But their hardware spec is carefully designed to cache just enough data for normal, _seamless_ DVD playback. They don't cache nearly enough to make much difference for a layer change.

    Drives designed for PC CD-ROM applications simply have a much bigger internal cache. They are also much more expensive, which is why you don't see so many of them.

    The real problem is that DVD players must have their own internal memory cache after the loader, but in all cases that I am aware of, it is wasted during non-seamless transitions. Mainly because a software architecture that doesn't waste it is significantly more complicated to implement. (Also, for high bit rate discs you would still need more cache than is typically used, if you really wanted to remove any visible transition).
     
  7. John H Ross

    John H Ross Screenwriter

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  8. Bill_Weinreich

    Bill_Weinreich Second Unit

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  9. Jeremy Little

    Jeremy Little Supporting Actor

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  10. John Kotches

    John Kotches Cinematographer

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    Not knowing how much the mechanisms are, I can't comment on that cost vs a DVD-R (which go for about US$50 these days).
    In terms of adding memory, that too isn't quite as cheap as you'd think.
    Sure, you can go out and buy a boatload of RAM, that's only about US$25, plus the drive for US$50. Given a 4-5x ratio between parts cost and retail price that's US$300-375.
    Of course we haven't yet:
    • Paid for any of the per player licenses
    • Added an MPEG decoder
    • Added DSP and DACs as appropriate
    • Built a chassis
    • Included a power supply
    • You need a remote control
    • What about output jacks
    • Did I mention you have to write interface software for operating the DVD-ROM drive yet?
    • etc, etc, etc
    I'm not trying to be difficult, merely pointing out that it isn't quite so simple as snapping in a DVD-ROM drive and Bob's your uncle.
    Regards,
     
  11. RoyGBiv

    RoyGBiv Stunt Coordinator

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    You should not think from the above that the RP-91 has seemless layer changes. It is noticeable. The pauses are brief but there. I have never had it break up the soundtrack on my Yamaha receiver, though.

    SMK
     
  12. John Cain

    John Cain Second Unit

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    Thx Steven..
     
  13. StaceyS

    StaceyS Stunt Coordinator

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    Ian's comments have reminded about the WHQL layer change test. It occurs at the max possible bit rate DVD allows.
     
  14. Ian Montgomerie

    Ian Montgomerie Stunt Coordinator

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  15. jeff lam

    jeff lam Screenwriter

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    I have a sony DVD and it has a noticable layer change. I also have a Yamaha receiver (RXV620) and have not had problems with it reading audio fast enough. I sure do hate those Layer changes though.
     
  16. StaceyS

    StaceyS Stunt Coordinator

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    I find the people most annoyed by layer changes are those coming from VHS. Coming from LD, I am simply happy not getting up to swap discs much less the 10-30 second side change.
     
  17. Jeff Pryor

    Jeff Pryor Supporting Actor

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    I've never owned a Laserdisc player, so I came over from VHS. But layer transitions don't bother me at all, my old RCA handles them very quickly, less than a second.
     
  18. Kwang Suh

    Kwang Suh Supporting Actor

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    I had thought that the layer pause was a function of the seek time of the drive, not the buffer.
     
  19. Jeff D

    Jeff D Supporting Actor

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    Stacey, I've been reading the progressive shootout for a long time and it always escapes me what WHQL is. What is it?

    Damn, went looking again and found it. Are there any sources for this disc?

    PS Any chance you guys will analyize a Tosh 4or5700?

    And best layer change I've seen.... My crappy Apex-600A, which does have the IDE drive.
     
  20. John Kotches

    John Kotches Cinematographer

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    WHQL == Windows Hardware Qualification Laboratory.

    You can order a copy from the MS Store, they run about US$50 -- I did just that.

    Regards,
     

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