Feature Request: Add Option to Combine Audio Tracks

[goobert]

Hello! I have been very happy with this project so far because it has minimized many of the tedious steps I usually take to compress videos for discord, but I think there's one more of those steps that could realistically be combined into this program.

That step being combining all of the separated audio tracks, because sending a video with multiple audio tracks on discord will result in a preview that only plays one of the tracks. With how it is currently, I use your program for the compression and trimming, and then take that output and put it through this FFMPEG script: ffmpeg -i "%~1" -filter_complex "[0:a:0][0:a:1][0:a:2][0:a:3]amerge=inputs=4[outa]" -c:v copy -c:a mp3 -map 0:v -map [outa] "%~1"_f.mp4

I want to avoid that 2nd step, so I would like to request a way to combine all the audio tracks into 1 within the program. It could simply be an optional flag in the command line and a switch in the web GUI (like how the "Approximate file size" switch works)

It would also be nice if you could choose which tracks get combined and which get deleted, or control the volume of those tracks, but that might either be too complex for the command line, or just too far unrelated for what the program is for.