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Dolby's TrueHD 96K Upsampling To Improve Sound On Blu-Rays

Posted by samzenpus on from the let-the-arguing-begin dept.

Stowie101 writes in with a story about your Blu-ray audio getting better. "The audio on most Blu-ray discs is sampled at 48kHz. Even the original movie tracks are usually only recorded at 48kHz, so once a movie migrates to disc, there isn't much that can be done. Dolby's new system upsamples that audio signal to 96kHz at the master stage prior to the Dolby TrueHD encoding, so you get lossless audio with fewer digital artifacts. The 'fewer digital artifacts' part comes from a feature of Dolby's upsampling process called de-apodizing, which corrects a prevalent digital artifact known as pre-ringing. Pre-ringing is often introduced in the capture and creation process and adds a digital harshness to the audio. The apodizing filter masks the effect of pre-ringing by placing it behind the source tone — the listener can't hear the pre-ringing because it's behind the more prevalent original signal."

6 of 255 comments (clear)

  1. Re:This is... by Anonymous Coward · · Score: 2, Insightful

    No kidding. A/B/X or GTFO.

  2. Worthless gimmick with no audible benefits by sahonen · · Score: 5, Insightful

    Dumb, dumb, dumb. An ideal sample rate upconversion results in something that *is* identical to the source. Mathematically. It's like re-encoding a 64kbps MP3 to 192kbps. If anything you are going to *lose* quality due to inherent errors in the process.

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    1. Re:Worthless gimmick with no audible benefits by PhrostyMcByte · · Score: 4, Insightful

      Mod parent up!

      A lot of people will see a graph of PCM and think up-sampling will help make the stair-stepping be finer, less noticeable, and thus improve quality. Unscrupulous audio companies love to take advantage of this belief with up-sampling tech.

      That belief is, of course, complete bullshit—the stair-stepping of PCM is merely a digital encoding which DACs use this to reproduce a full, fluid signal. There's literally nothing for up-sampling to do that could add any quality! The only thing it will do is introduce even more errors.

      In some cases DACs have even behaved worse at higher sample rates—meaning in that case you'd not only have more errors from upsampling, but also more errors from the DAC.

  3. Re:If you want to impress me by Ogi_UnixNut · · Score: 3, Insightful

    I'd prefer if they kept movies with the "100db difference". It is far easier to apply a dynamic compressor plugin than it is to undo studio-mastered dynamic compression. In fact, I hope they do the same with music as well, so that eventually we can apply as much compression as we want for a given environment/situation.

  4. Unsampling ... then re-sampling in 96KHz? by Taco+Cowboy · · Score: 4, Insightful

    Oh, c'mon !!

    This is one thing that simple does NOT make any sense

    If the thing was recorded in 48KHz, it's at 48KHz, and no matter how one can "un-sampling" that shit and then re-recording it in 96KHz (even at 96MHz or 96GHz), it does not boost _anything_ !!

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  5. Re:You cant hear it anyway. by guidryp · · Score: 4, Insightful

    Here is a link to the original paper by Dr. Peter Craven where he mathematically proves that an apodizing filter can make audible improvements in sound reproduction.

    You can't mathematically prove something sounds better. Most adults can't even hear 16KHz, let alone 20 KHz and beyond, or detect subtle variations in those ranges.

    You have to do double blind testing. Double blind testing has shown even real 24/96KHz can't be discerned from 16/44.1KHz by audiophiles and recording pros.

    Anything they are trying to sell beyond this is placebo snake oil.
    http://mixonline.com/recording/mixing/audio_emperors_new_sampling/