Identifying Atmos Content Is Like Pulling Teeth (1 Viewer)

[Robert Crawford]

Had thought Dolby Atmos means lossless audio like on discs, but apparently, that's not the case for streaming -- it seems just about as lossy as DD+... maybe even more so since it needs to handling the additional channels. That's disappointing.

I don't agree with that assessment! You got examples?

 

[ManW_TheUncool]

I don't agree with that assessment! You got examples?

Apparently, Dolby Atmos is actually (metadata?) encoded on top of either DD-Plus or TrueHD. It doesn't actually seem to be a completely separate audio format.

Technology Dolby Audio Dolby Digital Plus | Dolby Developer

Dolby Digital Plus (E-AC-3) provides up to twice the efficiency of Dolby Digital while adding new features like 7.1-ch audio, support for descriptive video services, and support for Dolby Atmos. Dolby Digital Plus is widely used by streaming and broadcast services to deliver surround sound audio...

developer.dolby.com

And based on user reports and also what's hinted in the above page (and would make practical sense), streaming services probably usually encode Atmos on top of DD-Plus, not TrueHD.

Here's a more detailed article explaining and pointing that out....

The ultimate guide to Dolby Atmos: what it is and how to get the best possible sound | Digital Trends

Dolby Atmos can be a great surround sound experience. But just because your gear bears an Atmos label, that doesn't mean you've got Atmos sound. Here's why.

www.digitaltrends.com

It specifically mentions Netflix and Amazon using DD-Plus-based Atmos and discusses further as though it's implicitly understood to apply to iTunes, et al as well.

It actually makes perfect sense that streaming services would likely use DD-Plus-based Atmos, not lossless TrueHD-based Atmos. And the services certainly have no incentive to inform us of the diff me thinks... Heck, they aren't even that good about providing easy access to accurate basic info as is...

_Man_

 

[Robert Crawford]

Apparently, Dolby Atmos is actually (metadata?) encoded on top of either DD-Plus or TrueHD. It doesn't actually seem to be a completely separate audio format.

Technology Dolby Audio Dolby Digital Plus | Dolby Developer

Dolby Digital Plus (E-AC-3) provides up to twice the efficiency of Dolby Digital while adding new features like 7.1-ch audio, support for descriptive video services, and support for Dolby Atmos. Dolby Digital Plus is widely used by streaming and broadcast services to deliver surround sound audio...

developer.dolby.com

And based on user reports and also what's hinted in the above page (and would make practical sense), streaming services probably usually encode Atmos on top of DD-Plus, not TrueHD.

Here's a more detailed article explaining and pointing that out....

The ultimate guide to Dolby Atmos: what it is and how to get the best possible sound | Digital Trends

Dolby Atmos can be a great surround sound experience. But just because your gear bears an Atmos label, that doesn't mean you've got Atmos sound. Here's why.

www.digitaltrends.com

It specifically mentions Netflix and Amazon using DD-Plus-based Atmos and discusses further as though it's implicitly understood to apply to iTunes, et al as well.

It actually makes perfect sense that streaming services would likely use DD-Plus-based Atmos, not lossless TrueHD-based Atmos. And the services certainly have no incentive to inform us of the diff me thinks... Heck, they aren't even that good about providing easy access to accurate basic info as is...

_Man_

Yeah, I read and discussed that stuff beforehand going back a year or so. However, I disagree with your assessment that it's only DD+ quality because today I heard a noticeable difference in the LOA Atmos audio on Vudu versus LOA on iTunes that's not Atmos audio.

 

[ManW_TheUncool]

Yeah, I read and discussed that stuff beforehand going back a year or so. However, I disagree with your assessment that it's only DD+ quality because today I heard a noticeable difference in the LOA Atmos audio on Vudu versus LOA on iTunes that's not Atmos audio.

Sure, the Atmos track should sound diff from non-Atmos track (and likely better due to additional 3D discrete sound, if nothing else), but doesn't mean they're not both based on lossy DD-Plus (instead of lossless TrueHD) though.

I had previously assumed Atmos automatically means lossless compression, but apparently not the case for digital streaming. Indeed, seems like it's usually not very high bitrate at something circa 768Kbps instead of the max rate DD-Plus actually supports -- that combo is what disappointed me.

To get lossless Atmos, still usually need to go w/ disc formats it seems.

_Man_

 

[Robert Crawford]

Sure, the Atmos track should sound diff from non-Atmos track, but doesn't mean they're not both based on lossy DD-Plus (instead of lossless TrueHD) though.

I had previously assumed Atmos automatically means lossless compression, but apparently not the case for digital streaming.

To get lossless Atmos, still usually need to go w/ disc formats it seems.

_Man_

Like I said, we've had previous discussions regarding that issue so I'm not going to revisit again. I will only say that I have difficulty distinguishing the Atmos soundtrack from an Atmos digital versus the Atmos disc of the same title. I spent far too many hours trying to do so.