Normalize audio loudness with EBU R128
audio
// what it does
Runs the loudnorm filter to bring audio to EBU R128 loudness targets: I=-16 sets integrated loudness to -16 LUFS, TP=-1.5 caps the true peak at -1.5 dBTP, and LRA=11 targets an 11 LU loudness range. This is how you make clips sit at a consistent perceived volume for streaming or podcasts rather than eyeballing gain.
// shell
$ ffmpeg -i input.mp4 -af loudnorm=I=-16:TP=-1.5:LRA=11 output.mp4// gotcha
As written this is single-pass, which applies dynamic normalization and can pump or miss the target; for accurate, transparent results run two-pass — first with print_format=json to measure, then feed the measured_I/measured_TP/measured_LRA/measured_thresh values back into the second pass.