FFMPeg Normalize Audio mp3

FFMPeg Normalize Audio mp3

We can use this command to find the max volume:

ffmpeg -i sound.mp3 -af volumedetect -f null -y nul &> original.txt

It will return something like

[Parsed_volumedetect_0 @ 0x7fa4f7d00000] n_samples: 4997376
[Parsed_volumedetect_0 @ 0x7fa4f7d00000] mean_volume: -27.6 dB
[Parsed_volumedetect_0 @ 0x7fa4f7d00000] max_volume: -12.3 dB
[Parsed_volumedetect_0 @ 0x7fa4f7d00000] histogram_12db: 663
[Parsed_volumedetect_0 @ 0x7fa4f7d00000] histogram_13db: 1846
[Parsed_volumedetect_0 @ 0x7fa4f7d00000] histogram_14db: 12347

Then we can use this command to normalize by max_volume

ffmpeg -i input.wav -af "volume=12.3dB" output.mp3