Dolby Atmos Passthrough

[Mari Marasu]

I know this has been asked before in the past, but would it be possible to get a Dolby Atmos passthrough option? I believe MP4 supports Atmos tracks now (please correct me if I’m wrong), and Apple & AppleTV support Atmos playback.

If not possible due to some technical limitation, could you fill me in on why for my own curiosity?

[Damiano Galassi]

EAC3+Atmos passhtru is already supported.

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[Mari Marasu]

Ah ok, I was specifically asking about TrueHD as I thought that this was the format Apple supported. Seems like there are a few past tickets open with this same request. My apologies for not searching around a bit first.

I’m not exactly sure what the technical difference is between TrueHD and EAC3+Atmos is. Would it be possible to include a transcode option from TrueHD to EAC3+Atmos? Would it be even worthwhile to do?

I tried testing a container conversion in FFMPEG (/Applications/ffmpeg -i /Users/Mari/Desktop/Tests/Amaze.mkv -c copy -strict -2 /Users/Mari/Desktop/Tests/Amaze.mp4) using the “Amaze (Lossless-ATMOS)” that’s listed here https://thedigitaltheater.com/dolby-trailers/ and it seems that nothing Apple native will playback this file’s audio after all.

I have renewed interest in Atmos support now that Spatial Audio has been released for the AirPod Pro's, and I get the feeling that devs will inevitably build support for Atmos+Spatial Audio in upcoming released of apps.

[Damiano Galassi]

I don’t think there is any open source audio encoder that supports Atmos, so that won’t be possible any time soon. Spatial Audio works with normal 5.1 and 7.1 too.

[Hongyu Shi]

Apple only supports E-AC3 Atmos currently, so it makes no sense to add TrueHD capability.

[Jackalworks]

Apple do not support TrueHD at all so far. TrueHD is lossless and uses an enormous bandwidth. EAC3 is a lossy compression codec.