I have some problem to add several fade effects to one audio file. When I try to use a command like this:
ffmpeg -y -i /home/user/video/test/sound.mp3 -af \"afad
The problem is that after fading out the audio you are trying to fade in the silence.
The solution is to disable the fade out filter when you want to start fading in.
You can achieve that with Timeline Editing to enable the filters for a particular amount of time.
The following example works just fine:
ffmpeg -i input.mp3 -af "afade=enable='between(t,0,3)':t=in:ss=0:d=3,afade=enable='between(t,7,10)':t=out:st=7:d=3,afade=enable='between(t,10,13)':t=in:st=10:d=3,afade=enable='between(t,13,16)':t=out:st=13:d=3" -t 16 output.mp3