Adjust Volume¶

ffmpeg -i audio.wav -af "volumedetect" v-n -sn -dn -f null /dev/null

Output will contain lines like:

[Parsed_volumedetect_0 @ 0x5652884a9540] n_samples: 491290624
[Parsed_volumedetect_0 @ 0x5652884a9540] mean_volume: -35.5 dB
[Parsed_volumedetect_0 @ 0x5652884a9540] max_volume: -11.1 dB

Apply the inverse of the max_volume to achieve 0dB:

ffmpeg -i audio.wav -af "volume=11dB" audio_adjusted.wav