Dolby Atmos and Audio Passthrough

Channels DVR Server
#1

According to another post audio passthrough is enabled on the latest beta, so today I installed it on my Shield TV and still don't get any audio passthrough and instead it looks like channels is doing the decoding then passing to avr as multi-channel.

My media is in H265 mkv containers and play fine except audio is not sent for decoding via receiver. Is the feature not actually working then for local content?

If I use Plex or Emby for the same content they pass the audio through and my receiver decodes it so not an issue with the container format

#2

Is this for eac3 or hd Atmos ?

#3

Please submit diagnostics from the app after trying to play the file

1 Like
#4

sorry for late reply, i've removed my local library from the product so only used through plex/emby as these detect the correct audio and passthrough to the devices. also found that a lot of the covers never showed correctly and doesn't seem to be a way of rectifying within the app

#5

passthru is dependent on the device and the app. I am not sure whether Channels passes bitstream on the shield but its a limitation on the Apple TV which sends LPCM so you'll get lossless bed channels (5.1, 7.1 etc) but eac3 Atmos only.

#6

channels can't do it on shield either which is why raised the initial query, the latest beta is supposed to allow passthrough but it doesn't work

#7

Any updates on this, I searched and didn't find anything conclusive. I have added channels DVR to my system alongside EMBY, which I have used for many years, my files on EMBY passthrough Atmos fine, but channels, come across PCM 2.1 for Atmos, multichannel 5.1 PCM when I change audio to 5.1 DD instead of ATMOS.

Nvidia Shield 2017, synology NAS, Pioneer LX503

#8

I seem to have this same issue -- not getting Atmos outupt from what should be Atmos content.

The Channels server is on an Intel NUC10i7FNHN with 32 GB RAM. I'm playing the content on an Apple TV 4K (original one, not the 2021 version) on the same home network as the server. The ATV is connected via HDMI to an Atmos-capable pre/pro. The ATV routinely plays Atmos content from other apps (Disney+, Apple TV+) to the pre/pro, which indicates that it's playing Atmos.

The content now is .mkv files ripped from Beatle Let It Be deluxe. MediaInfo confirms that the files have 7.1 Atmos audio:

Screen Shot 2022-05-07 at 6.44.39 PM
Screen Shot 2022-05-07 at 6.44.39 PM1942×570 109 KB

Channels DVR also seems to indicate that the files are Atmos:

Screen Shot 2022-05-07 at 6.41.23 PM
Screen Shot 2022-05-07 at 6.41.23 PM1920×990 101 KB

However, on playing these tracks via the Channels DVR app on ATV 4k through the pre/pro, the pre/pro indicates that it's playing "Multichannel 7.1 In" content.

Any debugging info would be appreciated. I submitted diagnostics from the ATV 4K, in case relevant.

Thanks!

#9

Dolby TrueHd cannot be passed through by an Apple TV. Only eAc3 with Atmos data. So Dolby Digital + with Atmos data. This is because this is what streaming services use.

TrueHD will be decoded to multi channel PCM like DTS is. But Atmos data will not be used.

#10

Thank you! I was just coming back to this thread to say that I had just realized this from reading at Atmos - Page 7 - MrMC. Thank you for confirming.

#11

What about the Nvidia shield?

1 Like
#12

A post was split to a new topic: ATSC3 audio issue on SHIELD