Article: Apple Music Lossless Mess Part 2: AirPlay

[The Computer Audiophile]

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[The Computer Audiophile]

6 minutes ago, bbosler said:

 

Isn't is possible that the stream retains whatever it is that triggers the HDCD light but alters the data in other ways?

There is no common way to alter a file and still leave the 16th bit untouched. Sure, if someone wanted to hack a file to make it pass this test, but be lossy, it could be done. However, in the real world, all common ways of modifying data destroy the 16th or 24th bit with the HDCD information (Conversion to AAC or MP3, Convolution, Volume control, etc…).

[The Computer Audiophile]

18 minutes ago, Marco Klobas said:

I forgot to ask: on macOS, did you always choose AriPlay within Music app? Have you tested choosing AirPlay through volume menu bar (system-wide) instead?

 

Holy $#!+. I thought this would only be worse and less "exclusive mode type" of thing. I just tried it and it actually is bit perfect to AirPlay 2 devices from a Mac once setup this way!

 

I will update the article!

[The Computer Audiophile]

Article updated with several UPDATED notes. 

 

Thanks to @Marco Klobas for mentioning this. 

 

With the configuration this way, it's possible to send lossless to both AirPlay 1 and 2 from the macOS!

[The Computer Audiophile]

1 minute ago, Marco Klobas said:

I know it's not AirPlay-related: don't you find the lossless streaming from iOS/iPadOS through USB CCK not being bit perfect particularly disappointing?

Absolutely!

[The Computer Audiophile]

4 minutes ago, new_media said:

 

Now that is surprising!

Totally. It's almost as if Apple made a mistake by allowing lossless this way, when it seems to have coded the Music app not to be bit perfect. Who knows. 

[The Computer Audiophile]

23 minutes ago, hopkins said:

Excellent write-up, thanks. This must have taken quite some time to prepare. 

Tedious. Then, five minutes after publishing Marco thinks of testing the system wide setting that changes a ton!

 

The power of the community. 

[The Computer Audiophile]

24 minutes ago, Marco Klobas said:

A quick visual recap of Chris' tests:

 

Via USB, Apple Music isn’t bit perfect on macOS. 

[The Computer Audiophile]

27 minutes ago, Marco Klobas said:

 

Sorry, Chris.

 

You're referring to your first test, isn't it?

 

I've updated the image.

Yeah, it’s confusing. The Music app can play local content via USB but perfect,  it not content from Apple Music the streaming service. 

[The Computer Audiophile]

9 minutes ago, James lee said:

I've done a lossless truncation of the unwanted bits from a polluted AM 16bit stream.

 

And it nulls properly so a true fix to retain lossless. You need a vst host.

Can you capture a partial track from Pearl Jam’s Live on Two Legs album and send it to me for testing?

[The Computer Audiophile]

I just tested @James lee's partial file capture and can verify it's bit perfect and illuminated the HDCD indicator on my DAC. 

 

Crazy that the file streaming from Apple Music isn't but perfect, but applying the right special sauce to it afterward makes it perfect. 

[The Computer Audiophile]

40 minutes ago, Jud said:

 

If I'm understanding @James leecorrectly (please tell me if I'm not), Apple is just "zero padding"? So being able to get bit-perfection by eliminating the zeros in registers 17-24 of each "word" doesn't seem remarkable to me. What does seem remarkable is a sonic impact that essentially results from writing 1 as 1.00000000.

I can set my DAC to look at either the 16th or 24th bit for the HDCD flag. I don’t see it on either, unless the files are run through the plugin. 

[The Computer Audiophile]

51 minutes ago, Jud said:

 

If I'm understanding @James leecorrectly (please tell me if I'm not), Apple is just "zero padding"? So being able to get bit-perfection by eliminating the zeros in registers 17-24 of each "word" doesn't seem remarkable to me. What does seem remarkable is a sonic impact that essentially results from writing 1 as 1.00000000.

 

In addition, I see the HDCD flag on the 16th when the track starts, but after less than one second, it's destroyed. 

 

If all that's happening is padding, it's really strange to start after the track starts. Plus, the HDCD flag should still be intact on the 16th bit with padding. Nonetheless, I change my DAC to look at both 16 and 24th bits, and neither has the HDCD flag. 

[The Computer Audiophile]

2 minutes ago, James lee said:

It's not zero. I cant tell you exactly what is in bit 24 but it is something.

DRM / watermarking?

 

 

[The Computer Audiophile]

Just an FYI, I've reached out to Apple seeking comment and a contact for technical questions. 

[The Computer Audiophile]

If anyone is interested in how watermarking has been used in the past with Universal content on Spotify, this is interesting. 

 

https://www.mattmontag.com/music/universals-audible-watermark

 

[The Computer Audiophile]

7 hours ago, Bevok said:

Introducing lossless to Airplay 2 with its multiple speaker support is certainly a big call with a lot of headwind in getting this to work robustly on wireless networks or Internet connections with a lot of latency or lack of bandwidth. I think it will be a while coming or have to use some kind of adaptive resolution ala Netflix rather than a straightforward bitperfect Alac. Not stating lossless support for Airplay in the official information and streaming AAC to airplay 2 devices may be quite intentional. A good robust listening experience I’m sure will be Apple’s number one priority. 

 

That said I’m a bit confused by that Roon forum post as although the Cambridge reports AAC it also says 16/44.1 (ie CD quality lossless) which is also what my Apple TV streams that album at (sounds wonderful by the way!).

16/44.1 is the sample rate and has nothing to do with lossy or lossless. MP3 and WAV can be 16/44.1. 

[The Computer Audiophile]

It bears repeating that sample rate has nothing to do with lossless or bit perfect playback. MP3 can be 44.1, just like WAV, FLAC, and ALAC. 

[The Computer Audiophile]

23 minutes ago, actuel audio said:

As far as bit perfect from a Mac, my understanding is that if the Audio MIDI Setup is set to the same as the source, then it is bit perfect to a DAC.

No, see this - 

 

 

[The Computer Audiophile]

13 minutes ago, pkane2001 said:

I’m not sure that Apple is lying. They provide high resolution music that’s at higher sampling rate than the CD and with more than 16 bits. They provide up to 23 bits out of 24 based on my testing. While it’s not bit-perfect, it is certainly high resolution and not lossy-compressed… at least up to 23 bits.

This is why I went down this road. Without looking into it, one has no clue if it’s MP3 or ALAC or where some DSP is taking place. 

[The Computer Audiophile]

3 hours ago, Jud said:

Don't get confused - FLAC and ALAC are lossless, they're simply compressed for storage purposes (usually - they can actually be uncompressed as well, which is sometimes done with FLAC because WAV doesn't have a standard way of storing metadata).

 

I'm really less concerned about any acoustic results of 16th or 24th bit alteration (though if there would be audible results from altering the 16th bit, I of course wouldn't like it) than I am about commercial/proprietary shenanigans.  Not only wouldn't I like having my use of the product limited; the history of these efforts shows they usually result in a fragmented market and consumer hassle. (Think of UPnP/DLNA non-compliant implementations, iTunes' lack of compliance with metadata standards, or various proprietary drivers for PC components and the hassles this has caused through the years.)

Yes, and if we can’t guarantee it’s bit perfect, we don’t know where it might change in the future. If it’s the 16th and 24th bits today, it could be more watermarking right in the audible range tomorrow (see what Spotify has in that area). 
 

Just send me bit perfect and it’s all good. Don’t send me bit perfect and I really don’t know what’s going on. 

[The Computer Audiophile]

2 hours ago, sooneramt said:

I was curious, when using the 1st generation Airport Express and an iOS device, is it only bit perfect when the volume on the iOS device is set at 100%? It sounds like if it’s set less than this then it will not be truly bit perfect, correct?

Correct. 

[The Computer Audiophile]

2 minutes ago, Marco Klobas said:

A follow up from Roon's forum: I made the usual Apple Music AirPlay recording/comparison test with a Mac acting as a receiver (via macOS Monterey) and the result is still not bit perfect. The AirPlay receiver in Monterey is seen as version 2; thus the result is unfortunately expected.

 

Interestingly, another user claimed that the bit perfect test is passed when a hi-res audio is sent through AirPlay to Monterey with Audio MIDI Setup properly set (Apple Music is not involved in this case). He used an RME ADI-2 DAC to prove it.

 

@The Computer Audiophile, have you already installed Monterey? Could you verify if a hi-res AirPlay audio is really possible with macOS Monterey?

I have Monterey installed, but no energy to test this one. I can't see sending audio to a Mac this way in the real world. 

[The Computer Audiophile]

3 minutes ago, DarwinOSX said:

Bluesound has made zero effort to integrate Apple Music when Sonos did it a long time ago.  I don't see how they are to be thanked for anything.

"A Bluesound Node 2i that supports AirPlay 2 and uses the newest version of Apple's AirPlay 2 chip"

There is no such thing as an "Airplay 2 chip".  Airplay 2 is entirely software.

Your assumption that Bluesound has made zero effort couldn’t be more incorrect. Bluesound has worked for years to get services only offered to the giants like Sonos. The company has had some successes and continues to push for more. 

[The Computer Audiophile]

12 minutes ago, Dutch Daniël said:

@The Computer Audiophile, I was on the verge of changing from Qobuz to Apple Music. This might look odd, but this is due to the lack of content available on Qobuz. But than I came across your tests and now have the shivers to proceed or not. I have an AURALiC Altair G1 an iPhone XS and iPad Pro 12.9 2 Gen, do I have to worry this will only work Lossy? I assume the Altair is AirPlay v1. I know I will lose true Hi-Res by losing Qobuz, but oldschool Lossless will be fine for my needs.

 

It's kind of a crapshoot. You can depend on using AirPlay and hope it works, knowing you have absolutely no chance of getting Apple to change if something happens. Or, you can lobby Qobuz to grow its catalog. Those guys participate in the forum here and do what they can to make us audiophile happy. 

 

However, if the music you like is only on Apple Music, then that may make the decision easy.