Audio Processing Callback

Mute a part of video and add new audio to video

I was testing this library

these are the various scenarios we are testing

Mute a part of video, For example We have a video of 1 minute, we want to mute from 20th sec. to 40th sec. keeping rest of the audio. i.e from 0 sec. to 20 and from 41 sec to 60 sec

for another video of 2 minutes long we want to add new audio to the original video removing original audio or keeping original audio overlaying new audio over it(both are different scenario)

can we keep original video and reverse audio

how can we do this.