7.1CH & Atmos audio support w/ H265 video conversion?

[Meatstar]

Does anyone have a recommendation for video conversion software with audio support for 7.1 & Atmos?
I've been using handbrake but have to use the audio pass-through to keep DTS 7.1. The file sizes get ridiculously large. I have a large collection of Blu-rays I want to store digitally using H265  with 7.1 channel audio. Ideally I'd like the files under 3GB. I'd really like to squish down that audio and still have 7.1 channels, Atmos would be nice. Too bad handbrake doesn't support AAC for 7.1 channels. I've tried Opus & Vorbis for 7.1 channel support, but many devices don't support these formats.
Any suggestions would be helpful...

[shirepirate]

this is probably what you're looking for:
https://www.videohelp.com/software/eac3to

that software has quite a learning curve, and i can't help you with it, but it should do what you are saying.
hardly worth it for 3GB files, you're talking about condensing a BD50 to that size while keeping TrueHD audio?
it will take a very long time and the video quality will suffer immensely unless you know what you're doing (in which case it will take an even longer time for a nice slow encode)