TrueHD BD Discs with 96khz Sampling Rate?

Discussion in 'Blu-ray and UHD' started by Mark_TB, Aug 30, 2008.

  1. Mark_TB

    Mark_TB Second Unit

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    Okay, I hope I don't sound like an idiot here, but I've spent most of the evening trying unsuccessfully to google an answer, so I hope someone here can help me out.

    This week I finally picked up a receiver with HDMI inputs (Yamaha RX-V663) so I could fully enjoy the sound from my BD and HD-DVD players (Panasonic BD-30 and Toshiba HD-A2).

    On the discs I've checked, the HD-DVD player outputs TrueHD as PCM at a sampling rate of 96khz. However, I've only found one BD in my collection with a 96khz sampling rate, and that was using DTS-HD -- everything else is 48khz, both TrueHD and DTS-HD.

    Why is this? Is it simply because most BDs use a 48khz sampling rate? Does it really make any noticeable difference, or should I just relax and enjoy?

    Thanks in advance for any responses!

    Mark

    EDIT: Is there a website that lists the sampling rates of HD discs?
     
  2. Craig_Ehr

    Craig_Ehr Second Unit

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    I would be careful in assuming TrueHD sampling rates on HD DVDs are encoded at a sampling rate of 96kHz. My PS3 can output good old red book CDs at 176.4 kHz (via upsampling.) I'm not familiar with Toshiba products personally, but it is possible your HD DVD is doing something similar. My understanding is the vast majority of movie soundtracks are recorded at 48kHz, and usually at only 16-bit resolution but that is changing more and more to 24-bit. I believe there are a few music-related discs encoded at 96kHz (or better), e.g. 'Dave Matthews and Tim Reynolds: Live at Radio City'.

    Here's hoping that DSD is made an optional codec for BD Profile 3 (but I'm not holding my breath.) [​IMG]
     
  3. Robert George

    Robert George Screenwriter

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    The new John Mayer BD has a 96/24 TrueHD track. There are no movie titles I am aware of with anything above 48kHz sampling rate audio.
     
  4. Mark_TB

    Mark_TB Second Unit

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    Okay, let me make sure I understand this. Most HD soundtracks are 48khz, and my Toshiba HD_DVD player is just "upconverting" to 96khz.

    My Queen - Rock Montreal BD states right on the packaging that it has a DTS-HD 96khz track and is the only disc I own that even mentions 96khz, so I assume that this is the exception rather than the norm (as are the Dave Matthews & Tim Reynolds and John Mayer discs).

    Does that sound about right?

    Also, I just want to thank everyone here at the HTF, because you all have been very helpful to this HD newbie. I'd really be lost without you guys.

    Mark
     
  5. Robert George

    Robert George Screenwriter

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    Pretty much. About the only discs you will find with anything above 48 kHz sampling frequency (actual) will be the odd music program. Upsampling in a player is not that uncommon, but should not be mistaken for the real thing.
     
  6. Wayne_j

    Wayne_j Screenwriter

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    The Celine Dion Vegas BD has a 24bit/96K stereo PCM track and a 5.1 24bit/96K DTHD track.
     
  7. Douglas Monce

    Douglas Monce Producer

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    The fact of the matter is the vast majority of sound effects libraries that are still used on most movies today are delivered on music CDs. Meaning that they are recorded at 44khz 16bit. Most location sound is also recorded at this rate, although some are going up to 24bit, its not universal yet.

    While a film may have been mixed at 96khz 24bit (which is a good idea for error correction), the original sounds being used in that film are likely no where near that resolution. So having the ability to play back at that resolution probably won't give you any advantages with the majority of material out there.

    Of course there is a move to upgrade everything to 96/24 and many films that used custom sounds probably are recording at that level, but no film uses 100% custom recordings.

    The point being the sound you hear in a movie is a mixed bag at best. In fact many movies are still using sound effects that were recorded for Dracula in 1932. The famous thunderclap called "castle thunder" can be heard in films from Star Wars to Back to the Future, to Transformers.

    Doug
     
  8. Ed St. Clair

    Ed St. Clair Producer

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    That answers my question.
    Would be GREAT if this turned into a list of high bit/sampling rate titles.
    Thanks again.
     

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