Breaking News: Dolby TrueHD Elevates the Quality of Lossless Audio on Blu-ray (Must Read)

Discussion in 'Blu-ray and UHD' started by Ronald Epstein, May 17, 2012.

  1. Dave Upton

    Dave Upton Owner
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    The branding of this whole thing is quite confusing - since the upsampling is one piece, the apodizing filter the other. In this case, i'm fairly certain Dolby just wants to push 96 kHz as the standard in playback from their perspective. The PDF below is pretty well written when it comes to explaining pre-ringing: http://www.amr-audio.co.uk/large_image/Tech%20Paper%203%20-%20Ringing.pdf
    Suffice to say, it's not below the threshold of our perception. While we may not "hear" pre-ringing on its own - the effect it has on our perception of the impulse as a whole is negative. Dolby has some very bright PhD's with psychoacoustics specializations working on this and other projects, and there is a lot of research out there indicating this is a real phenomenon. For my part - I was able to tell the difference in their tests, even with every intention of hearing nothing it wasn't subtle on certain recordings, mostly the orchestral samples.
     
  2. Chuck Anstey

    Chuck Anstey Screenwriter

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    Reading the PDF, this is nothing more than dealing with Gibb's Phenomenon, which has been known about for over 100 years (and he wasn't the first to discover it). Instant digital transitions from 0 to 1 cannot be replicated exactly in the analog domain and results in ringing on both sides of the transition. Basically an instant digital transition has infinite frequency components. I am very surprised this is a significant issue today given how well understood the phenomenon is and all the ways to deal with it.
     
  3. Jesse Skeen

    Jesse Skeen Producer

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    Not true- most of the first Blu-Rays and HD-DVDs that had TrueHD tracks also had separate tracks- Blu-Rays with standard Dolby Digital and HD-DVDs with DD Plus. The later releases no longer had the second tracks- every recent Blu-Ray release I've picked up with a TrueHD track has that as its ONLY English-language track. (Oddly, I just watched Adventures of Tintin which has a 7.1 DTS-MA track AND a 5.1 standard Dolby Digital track, also Tron Legacy has 7.1 DTS-MA and a 2-channel Dolby track.)
     
  4. bigshot

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    Preringing occurs in such a brief time frame... Less than one cycle of a frequency... there is absolutely no way that a loudspeaker could possibly reproduce it, and it's doubtful whether human ears can even hear it if they could. The best apodizing filter is the transducers themselves.
    Also, the stark contrast between "on and off" required to create preringing may exist in theory, but in the real world, signals do not get chopped off that squarely.
    Preringing is a red herring. This is just another example of gnat shaving by the audio industry. Hot air won't give Dolby the edge over its competitors. The problem isn't in the numbers. It's in the ears of stone deaf engineers who create the thick imbalanced mixes.
    What the industry really needs is hard and fast standards for channel balance in multichannel mixes. I keep running across 5:1 mixes where the center channel dialogue is buried, or rear channel information that is either too prominent or too recessed. The sub channel is horribly goosed on many movies too. The relative balance of underscore to the rest of the mix is another common problem, but that is just sound mixers with abysmal taste going for 11 on a scale of 1 to 10. These are balance issues that would be solved easily with a consistent calibration with an SPL meter, but as far as I know, no such standard calibration exists. (or at least it's consistently ignored for goosing the sound.)
     
  5. moovtune

    moovtune Stunt Coordinator

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    On True HD releases the Dolby Digital track is hidden, not necessarily a selectable track from the menu. If it wasn't there, and you had an older processor not capable of playing True HD, you wouldn't be able to select the True HD track and get 5.1. It's not a choice in the menu but it's there and taking up space.
     
  6. Adam Gregorich

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    I agree that mixes can be improved, I'm not sure I agree that it should be standards based though. It should represent what the director wants. Like all aspects of the film from script to cinematography, we will either agree or disagree with the choices made.

    Dolby's scientists say that you can hear preringing and that it does influence what you hear based on the way you process sound, not to mention the sound guys. I heard a difference in the sound with the various demos we heard (see this thread for more info on the clips used). In this instance the same mixes were used for both the TrueHD 48k and 96k encodes. The audio was at the same level for both encodes. There is more here than just hot air.
     
  7. FanboyZ

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    So future Dolby TrueHD tracks are going to feature 96khz up-sampled versions of 48khz soundtracks? Okay you can do that that's fine I suppose.
    I always wondered why Leon the Professional and Sex, Lise, and Videotape had 96khz tracks, were they too just up samples?
    Aren't most digitally recorded film soundtracks done at 48/24 or 48/16?
    I know Akira was done from the original analogue masters, so you can always get a deeper sample of something like that.
     
  8. Edwin-S

    Edwin-S Producer

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    I hope this doesn't catch on. I can't stand Dolby TrueHD tracks. I know it is a lossless format but but Dolby TrueHD tracks still sound lifeless and flat to me. They also force me to constantly have to crank the volume. The bottom line is they suck and 96 Khz sampling isn't going to make them any better in my book.
     
  9. Edwin-S

    Edwin-S Producer

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    That is how Dolby forced a person to upgrade their receiver if they couldn't decode lossless tracks. No Dolby Digital track meant Dolby Prologic only, if your receiver could not decode TrueHD. That is another reason why I prefer DTS-MA. I've upgraded now, but my old receiver could decode full 1500 DTS lossy, while I had to listen to Dolby Prologic with TrueHD discs that didn't have DD tracks. Thanks partly to Dolby I had to upgrade my receiver well before I wanted to.
     
  10. bigshot

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    I've supervised sound mixes for TV, and knowing that the mix is going to sound the same at home as it does on the mixing stage is a huge problem. A standard for flat frequency response and relative levels between channels would go a long way to help that.
    Having the director supervise the sound mix is great in theory, but for legacy titles, we are stuck with whatever tin ears were hired by the studio releasing the bluray. All too often this is a technical guy who really doesn't have a sense for making the track fitthe context of the film. The worst offender for this is Disney. Their 5:1 tracks for the animated features are often imbalanced, muddled messes. It seems the more a studio pays to remaster sound, the further it strays from the way the filmmakers intended.
    Dolby is a fine company, but I tend to listen to the opinions of independent engineers on the seriousness of preringing. To me, audio press releases and press demonstrations sit somewhere in the range of credibility between lawyers and used car salesmen.
     
  11. Hal F

    Hal F Stunt Coordinator

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    Excellent points.
    If one really wants to improve the quality of sound in their home theater they would be much better off spending their time and money finding a good pair of speakers. As I understand it, that is where the largest sound distortion can occur.
    And, as you've indicated, even the best audio systems can only accurately reproduce what the studio engineers have created. Garbage in garbage out.
     
  12. Adam Gregorich

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    Are you talking about the "Disney Enhanced Home Theatre Mix" that they have been putting on some of their animated titles?
     
  13. Adam Gregorich

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    Encoders are going to have the option of upsampling to 96 if they want to. While I can't speak for every title, there is a good chance that those were all upsampled. Film mixing is pretty much done at 48k as thats what the bulk of the tracks that go into the mix are at. It will be a loooong time (if ever) before most film mixes are done at 96k.
     
  14. Adam Gregorich

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    On my system Dolby TrueHD, PCM and DTS HD MA all sound fantastic to me. Can you give an example of a specific TrueHD disc that you didn't like? Have you listened to Transformers 3, Super 8 or Mission Impossible 4? Did you feel that way about any of those titles?
     
  15. RolandL

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    I remember when DTS first came out on DVD's. Almost everyone agreed that DTS sounded better than Dolby Digital. There was an article at that time that found one of the major differences was that DTS played louder than Dolby Digital. To our ears it sounded better just because of the increased volume.
     
  16. bigshot

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    Yes. Alice and Dumbo have the worst 5:1 mixes I've ever heard. Fantasia is the only one that sounds decent. Restraint and good taste isn't exactly the hallmark of Disney home video.
     
  17. Stephen_J_H

    Stephen_J_H All Things Film Junkie
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    And Fantasia would sound decent because the Fantasound stems have been restored, as opposed to spreading out a mono mix, as would be the case with Alice and Dumbo. Of these mono-to-5.1 conversions on Blu-ray, the best I've heard is Snow White, since all they attempted to do with that mix was re-create the ambience of a movie theatre, without trying to force directional music or dialogue.
     
  18. KPmusmag

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    I think the 40th Anniversary Home Theater mix of MARY POPPINS is the very worst ever. Actually, I guess Disney thought so too since they did not use it for the 45th Anniversary edition (boy those 5 years went by fast).
     
  19. bigshot

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    Another category of aural offender is when a movie has hit songs cut in and they use the music master instead of the movie track. The example that springs to mind is Hard Day's Night. Every time a song comes on I have to reach for the remote to adjust the volume. Some effects movies have screwed up dynamics too... Inaudible dialogue and earth shaking action scenes.
     
  20. Edwin-S

    Edwin-S Producer

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    Yes. I have Transformers 3 and MI:Ghost Protocol. I put them on, took a listen and immediately thought this sounds like Dolby TrueHD, especially the T:3 track. I opened up the audio menu and sure enough......Dolby TrueHD, we meet again. So many movies have been using DTS-MA that I thought I had heard the last of Dolby THD, but, alas, it turns up like a bad penny at the worst time. I know that DTS tends to be recorded at higher volume levels and that probably does give the perception of sounding better; however, with Dolby TrueHD tracks I have to crank the volume to 70 to get even close to DTS-MA. I don't want to have to crank a receiver up to the bleeding edge of distortion to get something that has some punch. Dolby THD tracks at something reasonable, like 55 - 60 on the dial, sound like they have a wet blanket laying on them.
    Also, I cannot see uprezzing a 48 Khz track to 96 Khz as having any noticeable effect in quality. If it was recorded at 48Khz then everything that is there is there. As I see it, taking a 48Khz track and redoing it at 96Khz isn't going to add anything except a lot of artificial interpolation. It isn't bringing out new information because there is nothing new to bring out. It is just adding a lot of useless processing.
     

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