SQ difference between Air Play Lossless and Local FLAC playback?

[Blue566]

Hello people, 
Thanks for Moode, it's awesome! 

I noticed a very significant SQ issue when playing Apple Music lossless via AirPlay and Moode compared to playing the same files in Flack from a local/networked drive. 
It's very obviously sounds like compression(?) A little like the difference between MP3 to FLAC. Strangely playing the same files from my phone (iPhone 14) with BT headphones (Sony WH-1000XM5) connected doesn't sound obviously bad. 

I don't even talk about 'high res files' just comparing 2 44.1 versions of the same song, one streamed over AP and the other local FLAC on a networked server. 
In theory there shouldn't be a different as lossless is lossless right? 

I checked that I have no EQ or even volume normalisation enabled on the phones Apple music settings and I'm playing everything on max quality (save Lossless files on my phone for offline play. Also in MA I am not using any gain or EQ settings. 

I noticed there are some 'wrapper' settings in MA for AP, perhaps it's one of those? 

https://ibb.co/RGKSj4t


My set up is an RPI4 running MA - with an Allo Digione Signature , connected with an ethernet cable to my router. Then to my DAC, Schiit Yggy 2, , Shciit Freya+, ATI 6002 power amp powering a pair of Pure Audio Project Trio 15 (horn 1) speakers. It's a very good and transparent system and this drives me mad

Please share your thoughts and ideas, thank you!

[yannig]

also had the same observations.
Even a Bluetooth stream sounds better than Airplay, to my ears.
I made this comparison with Youtube, on an Airpad.

I have no explanation.

And maybe Airplay2 is different, I only tested with Airplay1

but it really does sound like Airplay (Airplay1, at least) isn't really lossless.

[Blue566]

Thanks,
I'm trying both AP 1/2 without much success.
After digging a little it seems apple messed up and AirPlay over wireless (as opposed to an actual cable connection) disables the lossless part...

https://discussions.apple.com/thread/252848734

The irony is that my RPI is actually wired(!), I guess the 'wireless part' is playing from an iPhone...
Super frustrating ;(

[TheOldPresbyope]

First of all, AirPlay is a proprietary wireless communication protocol / stack.

If you're not up on the technology of communication protocols then some of the following quote from the Wikipedia AirPlay entry may be gobbledegook

The AirTunes [e.g., the audio] part of the AirPlay protocol stack uses UDP for streaming audio and is based on the Real Time Streaming Protocol.[24] The streams are transcoded using the Apple Lossless codec with 44100 Hz and 2 channels symmetrically encrypted with AES, requiring the receiver to have access to the appropriate key to decrypt the streams.[25]

[see the entry for more and for references]

The devil is in that phrase "transcoded using...." One might think that since ALAC is involved everything will be lossless but apparently not so with Apple Music (and I have no idea how many other apps). It's all proprietary so good luck sorting it out.

Just my 2-cents worth.

Regards,
Kent

[Tim Curtis]

From the shairport-sync repo
https://github.com/mikebrady/shairport-sync/issues/1465

[TheOldPresbyope]

So a couple of cups of coffee and several distractions later, I came back to this point.

I note the shairport-sync documentation includes AIRPLAY2  in which it is stated "Lossless and High Definition Lossless material is transcoded to AAC before it reaches Shairport Sync." This same is to be found in an earlier github issue https://github.com/mikebrady/shairport-sync/issues/1205

It seems to contradict the Wikipedia entry which states the transcoding is done with the Apple lossless encoder but perhaps that was talking strictly about classic AirPlay and not AirPlay 2.

Finally, according to the docs, shairport-sync can be built with the option to use the Apple ALAC decoder (requiring libalac). It isn't clear to me that the executable included in moOde includes this option. OTOH, I don't know what happens when this option is or isn't included.


Color me confused.

Regards,
Kent

PS - fortunately, between the overall quality of my audio system and the condition of my ancient ears, I don't find playback via moOde's Airplay renderer to be noticeably different.

[Tim Curtis]

Wikipedia is 100% factual ;-)

Shairport-sync has a built-in ALAC decoder, the "Hammerton" decoder. Apple's own ALAC decoder can be used as a replacement but it's not really needed. https://github.com/mikebrady/shairport-sync/pull/1505

[TheOldPresbyope]

Thanks.

I suppose I have must have known that at some point in the past but obviously I forgot. Seems like copious infusions of coffee are no longer enough.

Regards,
Kent

[Blue566]

Thank you people,
So let me rephrase the question, what lossless streaming services I can use on my iPhone to stream proper lossless music to my Moode audio RPI?

I saw a video ( https://youtu.be/GyUVF5Lcz-0 ) comparing the different services and strangely while Apple Music doesn't do lossless over AP, it seems that Amazon music unlimited does, I downloaded it and synced some of my playlists - it does seem to sound better than AM on my system. Thank you

EDIT: Is there a way to see in real time what AP codec/stream res Moode actually receives? In AP mode it just shows an option to disconnect the stream nothing useful on the UI - perhaps I'm a noob, thank you

[stefil]

(...)
what lossless streaming services I can use on my iPhone to stream proper lossless music to my Moode audio RPI?
(...)

I asked myself this question since a decade

Unfortunatly iPhone and Lossless are not "reconcialiable"

A time, best hope was bluetooth Apt-X but Apple won't implement it.
Apple wants you to buy captive products (airpods, apple tv etc.) on none of them handle real lossless (alac on airplay is downscale to CD quality as far as i know) 

Telling that my best experience for lossless is working around with uPnp protocol :

• You should consider you iphone as a remote : Upnp controller with  special apps or via a web ihm 
  
• You have to get an appliance that can handle streaming service : LMS is a good solution and will act as the source of music. you can implement it with a dedicated raspberry or perhaps mix LMS with moode audio, with material skin it's nice on iPhone
  
• Then moode audio will be the Upnp renderer by activating the feature "Upnp client"
  

 
Other option is to get a good DAP with uPnp capabilities and forget about "Apple product"

I will give more details later if you want.

Best regards