How to mux audio in mp4 file?

[neo_anderson]

i am having out of sync audio in nerodigital encodes, so is it possible to encode audio separately and then mux it in the mp4 video file? if yes, please tell me how! also, how to encode he-aac audio (ac3 to he-aac conversion)? help please!

[Doom9]

neo: you've been told by bond about the forum rules and this will be your last reminder: you're new to this, that's apparent, but we do require that you make a serious effort on your own first before asking for help (rule1). Your questions have been answered before. You should really look into the audio forum for audio questions (there's lots of stuff about AAC encoding so do not dare to ask there again.. the answers are in that forum so all that it takes you is looking and reading), and the same goes for mp4 file tinkering (that's what the container forum is for).