Apple TV+ Question Dolby Atmos bitrate via Apple TV on receiver that only supports Dolby Digital Plus (1 Viewer)

[Boun]

I've been doing extensive research on this and am still having a hard time truly understanding what my receiver is doing. Please forgive me if this is a dumb question.

I've been getting back into collecting 4K movies (both disc and digital). I usually buy digital when it's an incredible deal and it's in 4k. I love discs due to them having lossless audio but I've been trying to find out what quality audio my receiver is outputting movies at when purchased from iTunes that support Dolby Atmos.

From what I've gathered, Apple uses Dolby Digital Plus with Dolby Atmos support. Here's where I get confused as I have an older receiver that DOES NOT support Dolby Atmos, BUT it does support Dolby Digital Plus. Since my receiver supports Dolby Digital Plus, Is my 4K Apple TV streaming the audio from these movies in Dolby Digital Plus in the Bitrates between 384 and 786 that is supported with Dolby Atmos (Found in Dolby website) or is it defaulting to plain Dolby Digital at bitrates between 192-256?

Here's my setup:

Apple TV 4K (PCM) (HDMI direct to receiver)

Sony str dh770

 

[Jesse Skeen]

As you've probably noticed, the Apple TV outputs everything as multi-channel PCM and not any of the Dolby formats. I have no idea what it's doing when it's outputting Atmos, my receiver normally displays whether it's Dolby TrueHD or Dolby Digital Plus when decoding Atmos but doesn't when getting it from the Apple TV- I'm wondering if Atmos can actually be included in PCM signals and if so are there any Blu-Ray players that can output Atmos in a similar manner while retaining any secondary audio? Most discs are flagged for that even when they don't contain any, so you have to make sure it's manually set to Off to output Atmos properly. I've noticed on Apple Music that the Apple TV interface's sound effects are still heard while playing music in Atmos.

I don't know what format iTunes is using either- non-Atmos movies through the Apple app on my Roku output as standard Dolby Digital, I don't know if that's how they're all encoded there or if the Roku app is purposely being crippled to make the Apple TV more attractive (I have both and there are services where one works better than the other.)

 

[Neil S. Bulk]

As you've probably noticed, the Apple TV outputs everything as multi-channel PCM and not any of the Dolby formats. I have no idea what it's doing when it's outputting Atmos, my receiver normally displays whether it's Dolby TrueHD or Dolby Digital Plus when decoding Atmos but doesn't when getting it from the Apple TV- I'm wondering if Atmos can actually be included in PCM signals and if so are there any Blu-Ray players that can output Atmos in a similar manner while retaining any secondary audio?

The Apple TV sends Atmos via Dolby MAT.

 

[dpippel]

Oops.

 

[Mark-P]

The Apple TV sends Atmos via Dolby MAT.

I've always known I was getting Atmos from ATV4K through PCM but now I know why. Thanks for the info.

 

[Jesse Skeen]

Wonder if it would be possible to include that in disc players, even though menu sound effects aren’t used much anymore?