About infuse audio decoding

When I use Apple TV to connect to a soundbar, and the soundbar is connected to the TV, using Infuse to play movies with DTS or Dolby tracks, many are decoded into Multi Ch PCM format audio. However, some movies can be directly decoded into DTS or Dolby Atmos audio. I am using the Pro version of Infuse and it is connected to Emby. I want to know why this happens.

The Apple TV does not support audio passthrough, so most audio will be sent as multichannel PCM, which is a lossless format.

Some Dolby formats, such as Dolby Atmos, can be passed from the Apple TV when using Infuse.

More info on the available options can be found here.