ffmpeg's -vol parameter is confusing me. 256 => normal (i guess meaning same as input volume, no change) 512 => (double the volume - read this somewhere). So what to do for 3 times the volume? 1.5 times the volume? Basically, lets say I have the max sound amplitudes (audacity levels) in 3 files as: 0.8 0.6 0.9 I want to amplify in the first two files, so that max=0.9 in all files. What parameters of -vol I would use?