ffmpeg request 0.1

/home/user/bin/ffmpeg -y  -i track1.ogg -i track2.ogg -i track3.ogg -filter_complex "[0:0]volume=0.8:precision=fixed[a0]; [1:0]volume=0.8:precision=fixed[a1]; [2:0]volume=0.8:precision=fixed[a2];  [a0][a1][a2] amix=inputs=3:duration=longest:dropout_transition=3" output.mp3