Increase or decrease audio volume on cmdline

[shevegen]

Anyone knows a cmdline way to inrease or decrease audio volume?
so that it gets louder or more silent

At best of course any audio format, but I would be fine if its .wav or .mp3

[nm]

Do you mean adjusting playback volume in sound card mixer settings, or changing the audio volume of a music file permanently.

There are many command-line mixer tools. On Linux, take a look at amixer (ALSA tool) or aumix (ALSA and OSS).

For volume normalization, search for mp3gain, aacgain and vorbisgain.

To adjust volume of wav files, use Sox.

[shevegen]

Hi,

Permant modifications

alsamixer etc.. turning volume up is trivial :)
Also no "normalization", just a set to a target i can specify.

I will play with sox, thanks.

[nm]

Well, you can use mp3gain and aacgain to adjust gain by a specific amount. Using them makes sense if your input files are encoded and you want to keep the output in the same format. Otherwise you'll need to re-encode and quality will suffer.

[shevegen]

Otherwise you'll need to re-encode and quality will suffer.

Good point!
Do you by chance know by how much the quality will suffer?

[nm]

That will depend on the quality of the input file. 48kbps AAC will probably suffer noticeably, good quality 128kbps MP3 not so much (you probably won't hear the difference). But as I said, in these cases you can adjust the volume without re-encoding and without losing quality.