Wong You Jing said about 2 years ago on Adaptive Bitrate Streaming with Active Storage :
I'm unfamiliar with the bin code, but even copy pasting it directly gives me an error. 

It seems that aac is a built in default, and im on ffmpeg v4

[NULL @ 0x7f8c74813200] Unable to find a suitable output format for 'aac'
aac: Invalid argument

Just wondering if anyone has encountered the same, as my googling skills have failed me.