why we need dolby trueHD or DTS master audio?

Discussion in 'AV Receivers & Amplifiers' started by Raitzi, Sep 22, 2007.

  1. Raitzi

    Raitzi
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    I mean you can fit uncomressed audio of movie to bluray. So what is the need for dolby trueHD or DTS master audio?

    -thanks for advance
     
  2. ianjm

    ianjm
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    That's not true. Dolby Digital and DTS are both compressed formats. They're just very good (compared, to say, MP3).

    The new formats are uncompressed, and are the specified way of storing uncompressed audio on the new HD formats (Blu-Ray and HD-DVD). You need a new HD-DVD/Blu-Ray player (or firmware update) to understand what to do with this, although theoretically all players released should be able to understand these formats now.

    Currently, the options are to unencode (it's still encoded, even though it's not compressed!) the 6 channels in the player and send them out as 6 channel PCM. Or, less commonly (at the moment), the player can output the raw TrueHD/DTS Matser bitstream (which is why new receivers are making a big deal out of HDMI 1.3 support).

    The former needs HDMI 1.1 or above, the latter needs HDMI 1.3.

    Neither method will fit down the bandwidth available in an optical cable.

    Have a read of the sticky at the top of this forum about HDMI 1.3.

    Note: there could be errors in my post above, please feel free to correct!
     
  3. Jeff

    Jeff
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    True HD and DTS MA are compressed, they use a lossless compression method. LPCM isn't lossless, it's uncompressed. LPCM isn't good over HDMI because of jitter issues.
     
  4. dazza74

    dazza74
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    But LPCM can also be supplied as compressed (get compressed or uncompressed LPCM 5.1 option on Casino Royale on Blu Ray). Just find it interesting that I watch films with a DTS MA soundtrack yet there seems nothing really on the market currently that can decode it fully, currently in my case it gets scalled down to about 1.5MBPS (sorry may have got the characters round the wrong way etc). I've spent ages reading various threads and seem to get more confused.
     

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