MP3APPLYGAIN(1)

NAME
mp3applygain - apply replaygain to mp3 audio data

SYNOPSIS
mp3applygain gain mod file

DESCRIPTION
The mp3applygain program applies replaygain to mp3 audio data, decreasing or increasing the volume of the file based on the gain and mod arguments. It is designed for use with mp3 players that do not support replaygain information stored in ID3v2 or APEv2 tags, which is common in hardware mp3 players.

The gain argument should be an integer or floating point number of decibels to increase the volume. This can be negative to decrease the volume.

The mod argument should be an integer to modify the calculated gain adjustment for each mp3 audio data frame. This number can also be positive to increase the calculated gain or negative to decrease it. This number corresponds to the -m flag of the mp3gain program, and performs the same function.

EXIT STATUS
The mp3applygain program returns with exit code 0 if there is no error. If there is an error, the mp3applygain program returns with exit code 1 and prints an error to stderr.

EXAMPLES
To increase the volume of an mp3 file by 10.5 decibels:

    $ mp3applygain 10.5 0 foo.mp3

To decrease the volume of an mp3 file by 5 decibels, and also modify the calcuated gain in each frame to decrease it by 1:

    $ mp3applygain -5 -1 foo.mp3

SEE ALSO
mp3gain(1)

HISTORY
The mp3applygain program was originally derived from the mp3gain program, with most of functionality being removed, such as the ability to calculate replaygain. The only part remaining is the part that applies gain to an mp3 file.

CAVEATS
The mp3applygain program modifies the mp3 file itself, and does not store undo information. It should only be run on disposable copies of an mp3 file, and not on the only remaining copy. If this is run on the only remaining copy, the changes it makes can be undone by running the program with the gain and mod arguments multipled by -1.