Configuration¶

Musium reads all settings from a configuration file. The location of the config file is passed as an argument to the program. Config files consist of key-value pairs with = separator, and support # for comments.

Example¶

# Note: listening on port 80 requires CAP_NET_BIND_SERVICE.
# If you want to run as an unprivileged user, use a port beyond 1024.
listen = 0.0.0.0:80

library_path = /home/media/music
db_path = /var/lib/musium/musium.sqlite3

audio_device = UMC404HD 192k
audio_volume_control = UMC404HD 192k Output

high_pass_cutoff = 30 Hz

Settings¶

The following settings are available. Unless noted otherwise, all options must be specified exactly once.

listen¶

The address and port to bind to, for example 0.0.0.0:80. Use 0.0.0.0 as the address to listen for external connections and make the player available to the entire local network. Use localhost to listen only on loopback.

The listen address is optional and defaults to 0.0.0.0:8233.

library_path¶

The directory to recursively scan for flac files.

db_path¶

Musium uses SQLite to store persistent state. The db_path setting specifies where that database is stored. The directory where the database is to be stored must exist.

The database contains the listens database, cached tag metadata, loudness information, and cover art. Updating the listens database causes disk activity for every track, so it is recommended to keep the data path on a silent storage medium. See also the section on disks for more details.

The size of the database is dominated by cover art and waveforms. On average an album uses 62 kilobytes of disk space. For 1600 albums, that would be about 100 MB.

audio_device¶

The Alsa card used for playback. When the configured card cannot be found, Musium will list all of the cards that are available. You can also list cards manually with aplay --list-devices. The name of the device is listed between square brackets. Musium uses the Alsa hardware device directly, there is no need nor support for PulseAudio.

audio_volume_control¶

The Alsa simple mixer control that controls playback volume. Often there are controls named Master, PCM, and Speakers, but this differs from card to card. Use amixer scontrols to list available controls. Be sure to run this with the right privileges (possibly as superuser, or as a user in the audio group) to reveal all available controls.

Musium assumes exclusive control over this mixer control, so you should not manipulate it manually with tools like Alsamixer after starting Musium. In particular, Musium adjusts the volume to perform loudness normalization, so even for a constant target playback volume, Musium will manipulate the mixer control.

high_pass_cutoff¶

Apply a high-pass filter to the output, with the given cutoff frequency. The value must be an integer and include the Hz unit as suffix. This setting is optional and defaults to 0 Hz (so no frequencies are filtered).

A high-pass filter is useful in situations where your speakers reproduce low frequencies — perhaps even louder than intended due to suboptimal room acoustics — that are unpleasant or unwanted. Especially 2020s albums can be bass-heavy, and taking off the low end can help to allow greater playback volume without making the room sound saturated. Values around 50 Hz are suitable for this use case.

The high pass filter is not perfect. It has a gain of -3 dB at the cutoff frequency, and a rolloff of -12 dB per octave. For example, at a cutoff frequency of 50 Hz, a 25 Hz tone would be diminished by 15 dB.

exec_pre_playback_path¶

When Musium starts playback from an idle state, it can optionally execute a program before continuing. For example, you can use this to ensure that your speakers are powered on. See the page about Trådfri control for how to do this with Ikea Trådfri outlets.

The value is the path of a program to be executed. It is not possible to pass arguments to the program. Instead, you can create a shell script that will call the program with the required arguments. Musium waits for the program to exit before starting playback. However, if the program does not finish within 10 seconds, Musium will continue playback anyway. After 20 more seconds, Musium will kill the child process if it is still running.

This setting is optional. When it is not set, Musium starts playback instantly.

exec_post_idle_path¶

After playback ends, Musium can optionally execute a program. For example, you can use this to submit listens to Last.fm, or to turn your speakers off when there is no longer any music playing. See the page about Trådfri control for how to do this with Ikea Trådfri outlets.

The value is the path of a program to be executed. It is not possible to pass arguments to the program. Instead, you can create a shell script that will call the program with the required arguments. If the program does not finish within 30 seconds, Musium will kill the child process.

You can control the time between playback ending, and executing the program, with the idle_timeout_seconds setting. If playback resumes within this time, Musium does not execute the post-idle program. It will execute the pre-playback program when playback resumes, regardless of whether the post-idle program was executed.

This setting is optional.

idle_timeout_seconds¶

The time between playback ending, and executing the post-idle program, in seconds. This setting is optional and defaults to three minutes. This setting is only useful in combination with exec_post_idle_path.