DVD format specification question

Discussion in 'Archived Threads 2001-2004' started by Neil Joseph, Sep 30, 2002.

  1. Neil Joseph

    Neil Joseph Lead Actor

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    Real Name:
    Neil Joseph
    At the risk of placing my thread in the wrong area of the HTF [​IMG], I need to know what the exact spec for the ".1" LFE track is. Is it frequency limited, 0-200Hz for instance, or can it accomodate a signal up to 20kHz like the other tracks? I ask because the .1 track was, if I remember correctly, to be able to contain any track at the discretion of the studio but to date, it has only been used to contain the low frequency information (bass) of a soundtrack.
     
  2. MikeEckman

    MikeEckman Screenwriter

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    I am 98% positive that what we consider to be the .1 channel is actually a full frequency channel in the compressed audio stream, just due to the Dolby Digital and DTS specifications, the rolloff is encoded into the data, and not limited by the DVD specification.
     
  3. Vince Maskeeper

    Vince Maskeeper Producer

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    Not DVD specific- but band limited at 120hz in Dolby. I assume DTS is the same.
    http://www.dolby.com/tech/c.in.0011.LFE.pdf
    This is a brick wall filter- meaning anything coming close to this freq would be curbed off in a displeasing manner. Therefor, it is often rolled off well below 120hz.
    Technically, a 6th channel could be used to carry other freq if the 6 channels were encoded using some other codec other than DD and DTS-- but these codecs automatically kill everything above 120.
    -V
     

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