Apple TV and Dolby Digital Output (posts from 'Music streaming on Apple Music in 5.1' thread)

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Cheezmo

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The best part of this is "Note: 5.1 and 7.1 audio files generated automatically and/or algorithmically from a stereo master are not allowed."

Same thing for Dolby Atmos.

So everyone that has been claiming that much of the Atmos material must be "generated" are barking up the wrong tree. Apple doesn't allow it.
 

EricKalet

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The best part of this is "Note: 5.1 and 7.1 audio files generated automatically and/or algorithmically from a stereo master are not allowed."

Same thing for Dolby Atmos.

So everyone that has been claiming that much of the Atmos material must be "generated" are barking up the wrong tree. Apple doesn't allow it.
Definitely a golden nugget find, glad I dug around, and dug deeper to find this. Naysayers please now find your way to the exit. "mic-drop" :SB
 

quicksrt

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Definitely a golden nugget find, glad I dug around, and dug deeper to find this. Naysayers please now find your way to the exit. "mic-drop" :SB
Well, not so fast, there are always exceptions and downright lies. Just like HDTracks has been caught several times selling up-res'd files from CDs, it can happen here too.

But it's still a golden nugget that I am happy to see unearthed right about now.

:dance:51QQ:dance
 

Cheezmo

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Well, not so fast, there are always exceptions and downright lies. Just like HDTracks has been caught several times selling up-res'd files from CDs, it can happen here too.

But it's still a golden nugget that I am happy to see unearthed right about now.

:dance:51QQ:dance
Of course someone could lie and possibly trick them, but the policy is sound.
 

EricKalet

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Well, not so fast, there are always exceptions and downright lies. Just like HDTracks has been caught several times selling up-res'd files from CDs, it can happen here too.
For sure, Apple depends on the studios/rights owners to send the proper tracks/albums per the agreement. Certainly mistakes have happened too and likely tracks and albums have been up-converted in the past and sent as requested to meet the requirements.
 

fredblue

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oh dear.. 😔 why exactly are we speculating on this in the Dolby Audio on Apple Music thread?

i can understand some people's skepticism over the Dolby Atmos offerings as there's been some inconsistency in the mixes, arguably underused Heights, Rears etc., so i can see why there may be some speculation, although personally i think with Atmos Music its all just the same inconsistencies in mixing that we've encountered in Quad and 5.1 music over the years and nothing to get into a lather over.

however of all the music released in 5.1 and 4.0 on Apple Music in Dolby Audio so far, absolutely everything i have played that has been posted about here at QQ as far as i can tell has all been the genuine previously released Quad and 5.1 mixes, with no upmixing going on.

without specific examples of potential upmixing being provided by naysayers rather than speculation without foundation, its all mere hearsay that's damaging to the reputation of Spatial Audio's Dolby Audio offerings at this early stage of proceedings and really to me it feels quite baseless and honestly plain wrong.
 

marcb

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Ok, but this just tells us what the original source files submitted to Apple must be. It’s not at surprising they need to be submitted at industry standard resolutions.

So my read of this is the lossless 24 (or 16) bit PCM deliverable files are downconverted by Apple to lossy DD+ and then upconverted back to lossless 24/48 PCM at the AppleTV for delivery over HDMI to a receiver/pre-pro. Am I mis-reading it?
 
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marcb

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I can not find anywhere on Dolby's site or Apple site that Dolby Digital E-AC-3 (DD+) is streamed by ATV at 24 bit.

I did find this and highlighted what stands out to me as the final say on how DD+ is handled by audio equipment: "By means of an elegant conversion process, Dolby Digital Plus bitstreams, regardless of their source bit rate, are repackaged into a standard Dolby Digital format at 640 kbps. The conversion process does not decode the signal to PCM and reencode it, therefore avoiding the introduction of compounding coding artifacts." https://professional.dolby.com/globalassets/dolby-digital-plus/dolby-digital-plus-audio-coding-tech-paper.pdf
The AppleTV doesn’t stream out DD+. It receives DD+ and upconverts it (decode & convert...whatever) to 24/48 PCM. Just check what your receiver is receiving. Your receiver is not handling DD+; it’s handling PCM.
 

steelydave

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I've moved all the posts from the 'Music Streaming on Apple Music in 5.1' thread concerning Dolby Digital output here.

Having said that, this thread is about a ball-hair away from being sent to the Phantom Zone (with General Zod) permanently.

For the record, @marcb is correct in his terminology when he says that the ATV taking lossy Dolby Digital and outputting it as lossless PCM (as opposed to bitstreaming it untouched in its original container so your AVR can do the DD decoding) is upconverting/upconversion, just like if you took an mp3 and converted it to WAV or FLAC you'd call the process the same thing. Please consider this matter settled - I mean, don't you have better things to do with your time than argue about the definition of a word? I know I do.

I'm particularly disappointed in the two pages of pedantic point-scoring going on here, especially in light of the fact that I had to spend time a couple of days ago telling people here to be civil, kind and courteous to each other. This a (friendly) final warning that this kind of behaviour (no matter how well-intentioned) won't be tolerated, and posts/threads will be deleted if it carries on, and individual users will be sanctioned if necessary.
 

HomerJAU

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The AppleTV doesn’t stream out DD+. It receives DD+ and upconverts it (decode & convert...whatever) to 24/48 PCM. Just check what your receiver is receiving. Your receiver is not handling DD+; it’s handling PCM.
My AVR shows ‘DD+ Atmos’ when I play Atmos movies and music from my AppleTV via HDMI. Same as when I play Netflix on my TV. Atmos streams as ‘DD+ Atmos’ via HDMI.

If these files are not being decoded from Atmos how can we hear Atmos? We’d be listening to PCM. The whole point IS streaming services deliver Atmos and we can LISTEN to Atmos.
 

EricKalet

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The AppleTV doesn’t stream out DD+. It receives DD+ and upconverts it (decode & convert...whatever) to 24/48 PCM. Just check what your receiver is receiving. Your receiver is not handling DD+; it’s handling PCM.
I don't know about everyone else's setup or tech, but I'm seeing Atmos IN and 7.1 OUT no "upconversion or conversion to PCM"
-or-
for Dolby Audio tracks...interestingly enough...5.1 PCM IN...then 5.1 OUT

Atmos1.jpg


DolbyAudio1.jpg
 

marcb

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My AVR shows ‘DD+ Atmos’ when I play Atmos movies and music from my AppleTV via HDMI. Same as when I play Netflix on my TV. Atmos streams as ‘DD+ Atmos’ via HDMI.

If these files are not being decoded from Atmos how can we hear Atmos? We’d be listening to PCM. The whole point IS streaming services deliver Atmos and we can LISTEN to Atmos.
Hmmm.

The Atmos metadata is supposedly contained in the 6 & 7 height channels of the 7.1 PCM stream from the AppleTV.

Are you set for uncompressed audio output in your apple tv settings?

I’m guessing maybe your receiver sees that Atmos metadata and indicates DD+ Atmos rather than 7.1 24/48 PCM?
 
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