How can I add extra audio streamS codecs to my files before they get uploaded

I am trying to add extra audio streams to my files with both 7.1, 5.1 and 2.0 respectively (aac, ac3, eac3, truehd, dts to aac, ac3, eac3, truehd, dts). How do I go about doing this? I have tried using both tdarr and unmanic, but I don't know what I'm doing. I want take whatever audio the files come with and duplicate it/add extra audio streams with different audio codecs such as aac, ac3, eac3, truehd, dts as well different audio channels such as 7.1, 5.1 and 2.0 respectively, although I am not sure if 5.1 to 7.1 is possible or even necessary.

Solution 1:

If I'm understanding correctly, you want to take the input audio and transcode it to multiple different lossy audio streams. If so, you want the -map command:

ffmpeg -i input.mka -map 0:a:0 -c:a:0 aac -b:a:0 480k -map 0:a:0 -c:a:1 ac3 -b:a:1 640k -map 0:a:0 -c:a:2 eac3 -b:a:2 448k out.mka

etc. That should give you a general idea. See map as well as here for info on audio codecs and channel mappings. Note that ffmpeg's DTS encoder is considered experimental.