Layer Changes and DVD players

Discussion in 'Blu-ray & DVD Players & Recorders' started by Andy Dee, Oct 20, 2002.

  1. Andy Dee

    Andy Dee
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    Hello..Newbie Alert..so be gentle:p

    I am wondering how you tell whether one player is better than another, in regard to layer changes.

    For instance,.. Do manunfactures quote a figure that corresponds to the timing of layer change?
    I realise Each DVD will vary, but i also am led to belive some DVD players react faster than others on the same DVD.

    What is it the faster responding DVD players have that the others dont?

    Is it a Buffer of sorts, or a more powerful laser?:confused:

    Is there anything on the Spec of a Player that will guide me towards knowing the Speed of its layer change?

    What sort of questions should i be asking b4 buying?

    Hope all this makes sense!

    TIA

    Andy
     
  2. AOD

    AOD
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    From what I can see not many manufacturers make a big thing of their player's layer change performance.

    Occasionally when you see a new model being announced for example in the news section of the HCC website the press release may make special mention of the fact that the player has X amount of buffer memory that allows it to execute seamless layer changes.

    Basically the player has to be able to buffer enough data to supply a constant video stream whilst the layer change occurs. Cheaper players aren't so concerned by this (maybe this type of memory isn't cheap??) and don't usually bother.

    I think you would probably have to audition the players you're interested in and see how they measure up against each other.
     
  3. nigel_williams

    nigel_williams
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    As you say, it can vary from disk to disk but some players perform better than others by using a buffer. Some disks place layer changes in very subtle scene changes so it's difficult to see anyway.

    I found that my Arcam DV27 does layer changes quite rapidly, much quicker than my old Panasonic - they are still visible, but barely noticeable. This is probably due to the progressive output which is a form of buffer in itself.

    I'm not sure manufacturers are in the habit of quoting layer change figures but I think it's fair to say that better quality players will be smoother and quicker than say a £70 player from Tesco. If you're willing to get something better than the bargain basement players, you'll find it's barely a distraction.

    Hope that helps.
     
  4. mij

    mij
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    The new Denon DVD-900 has a 2mb buffer that they say eliminates this problem.

    mij
     
  5. buns

    buns
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    one of my players can take a while to change.....there is a definite sound drop out as well, but im used to it and dont really worry now days!

    ad
     
  6. Reiner

    Reiner
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    While the time to change the layer may be different (depending on make and model) I think it can only be avoided by using a buffer. Unfortunately not many manufactures offer this feature and the whole thing isn't helped by the fact that some layer changes are put into the middle of a scene rather than inbetween chapters.
     
  7. Andy Dee

    Andy Dee
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    THanks all.

    Good few pointers for questions to be asked!
     
  8. keyser

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    What players use buffer to avoid the layer switch delay... do Philips dvd players use a buffer?
     
  9. keyser

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    What players use buffer to avoid the layer switch delay... do Philips dvd players use a buffer?
     
  10. morg

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    i have never had any problems with the layer change on
    the denon dvd900. the last player i had was a toshiba sd220
    on wich the layer change was noticable
     
  11. MrC

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    the following Denon players all have memory buffers
    DVD-900 2 meg
    DVD-1600 3 meg
    DVD-2800MkII 4 meg
    DVD-3800 4 meg
    DVD-A1 4 meg
     
  12. daninthemix

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    I guess it isn't helped by the fact that a lot of AV receivers require a second or so to 'lock on' to the digital audio stream, turning a half second layer change into almost two seconds of lost sound :confused:
     
  13. James45

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    Denon are the only manufacturer that seem to place any importance on eliminating the layer change, i wish more would follow suit, memory costs are almost non existant at those sort of sizes.
    surely larger buffers that buffer sound as well would eliminate the associated problem of sound drop-out.
    My pioneer is fairly rapid, in some cases bearly noticable, but a friend's tesco cheapy locks for ten seconds!!:eek: :eek:
     
  14. chic

    chic
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    my cheap grundig had seamless layer changes never noticed any on any pf the discs i had , the bad thing about the player is that it was very fussy on which discs it played and it took ages to load a disc so i replaced it with the toshiba 510 which plays everything but the downside was you could notice the layer change, but it only lasts a second so its not too bad
     
  15. Blaz

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    I got the DVD-900 and I haven't noticed any layer changes yet so the 2mb buffer is a good feature and it helps. My old Sony dvd player had a little layer delay, but my new Denon eliminates it.
     
  16. gmt steve

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    An interesting point is that Superbit DVDs have a seamless layer change, so why can't all discs? I know the answer is that it's in the DVD spec', but it's still a little galling.
     
  17. Adam Barratt

    Adam Barratt
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    Buffer memory makes no difference to layer change times. This is primarily determined by the player's laser tracking ability and the speed of the drive mechanism.

    The DVD spec calls for non-seamless layer changes. This requirement means that nearly all DVDs command DVD players to 'dump' their buffer memories when a layer change occurs. Increasing the size of a player's buffer memory wouldn't change this. Players that have faster layer changes are those with multi-speed ATAPI-based DVD drives, such as Denon's newer players, a handful of Panasonics, Meridians and many of the cheaper players. These players track the second layer more rapidly and are able to re-buffer data much more quickly than the single-speed drives found on most DVD players. This increased re-buffering speed significantly reduces visible layer change pauses, but won't totally eliminate them.

    Superbit discs (other than The Mask of Zorro) do not trigger this buffer memory dump, hence their seamless layer changes. This is officially against DVD specifications, but there haven't been any compatibility issues that I know of so we may start to see these from other studios.

    Adam
     

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