Emby for Fire TV - Multichannel PCM Output

[Kakoserrano 0]

Hello guys,

I have a Fire TV Max connected to a Onkyo receiver. 

In Emby, when I uncheck the options to passthrough DTS, DTS-HD, True-HD the receiver is getting PCM multichannel sent by the Fire TV (It says something like Software Decode in Emby Information)

That's great and what I wanted. My question is: Is this PCM that is being sent from the fire TV Lossless or this software decoding process turns the audio into a Lossy version of PCM?

I know it's a very specific and tricky question, but I'm trying to get the best audio possible from the Fire TV that do not passthrough True HD and DTS-HD.

Thanks! and sorry for my lousy english.