This is the question that was closest to my problem: Ffmpeg add new audio in video (mixing 2 audio)
I need to insert audio from 2nd input file too but WITHOUT cutting first audio stream. I need them to actually overlap in this short fragment.
<1.aac playing>, <1.aac + 2.aac MIX>, <1.aac playing>
Tried to apply
-itstimeoffset but it doesnt give desired effect.
Though it doesnt fail error-wise, the problem is with output. Said command will provide me with a file where both inputs are combined in a sequential way WITHOUT required delay. For example, im combining 1.aac and 2.aac. The result will be: <2.aac playing>. <1.aac playing> (it somehow swaps 1 and 2 places, prob because of - longest operator i used but this is off-topic).
While i need: <1.aac playing>, <1.aac + 2.aac both playing>, <1.aac playing> with timed funcionality
ffmpeg -i 1.mpg -i 2.aac -filter_complex "[0:a]atrim=end=13.90,asetpts=PTS-STARTPTS[aud1]; [1:a]atrim=0:1.30,asetpts=PTS-STARTPTS[aud2]; [0:a]atrim=start=13.90,asetpts=PTS-STARTPTS[aud3]; [aud1][aud2][aud3]concat=n=3:v=0:a=1[aout]" -map 0:v -map "[aout]" -c:v copy -c:a libvo_aacenc output.mp4 achieves TIMING i need, but it makes only 2nd input to play sound in an inserted period. While i need both of them playing.