Options - librespot-org/librespot GitHub Wiki

Type	Short	Long	Description	Hint
Option	h	help	Print a list of options and flags.
Option	c	cache	Path to a directory where files will be cached.	PATH
Option		system-cache	Path to a directory where system files (credentials, volume) will be cached. May be different from the cache option value.	PATH
Option		cache-size-limit	Limits the size of the cache for audio files. It's possible to use suffixes like `K`, `M` or `G`.	SIZE
Flag		disable-audio-cache	Disable caching of the audio data.
Flag		disable-credential-cache	Disable caching of credentials.
Flag	q	quiet	Only log warning and error messages.
Option	n	name	Device name.	NAME
Option		device-type	Displayed device type: `computer`, `tablet`, `smartphone`, `speaker`, `tv`, `avr` (Audio/Video Receiver), `stb` (Set-Top Box), `audiodongle`, `gameconsole`, `castaudio`, `castvideo`, `automobile`, `smartwatch`, `chromebook`, `carthing`, `homething`. Defaults to `speaker`.	TYPE
Option	b	bitrate	Bitrate (kbps): `96`, `160`, `320`. Defaults to `160`.	BITRATE
Option		onevent	The path to a script that gets run when one of librespot's events is triggered.	PROGRAM
Flag		emit-sink-events	Run PROGRAM set by `--onevent` before sink is opened and after it is closed.
Option	V	version	Display librespot version string.
Flag	v	verbose	Enable verbose output	PROGRAM
Option	u	username	Username used to sign in with.	USERNAME
Option	p	password	Password used to sign in with.	PASSWORD
Option		proxy	Use a proxy for HTTP requests. Proxy should be an HTTP proxy in the form `http://ip:port`, and can also be passed using the all-lowercase `http_proxy` environment variable.	URL
Option		ap-port	Connect to an AP with a specified port. If no AP with that port is present a fallback AP will be used. Available ports are usually `80`, `443` and `4070`.	PORT
Flag		disable-discovery	Disable zeroconf discovery mode.
Option		backend	Audio backend to use. Use `?` to list options. Define also the `device` option when using `pipe`	NAME
Option		device	Audio device to use. Use `?` to list options if using `alsa`, `portaudio` or `rodio`. Enter the path to the output when using `pipe`. Defaults to the backend's default.	NAME
Option		format	Output format: `F64`, `F32`, `S32`, `S24`, `S24_3`, `S16`. Defaults to `S16`.	FORMAT
Option		dither	Dither algorithm: `none`, `gpdf`, `tpdf`, `tpdf_hp`. Defaults to `tpdf` for formats `S16`, `S24`, `S24_3` and `none` for other formats.	TYPE
Option	m	mixer	Mixer to use: `softvol`, `alsa`. Defaults to `softvol`.	MIXER
Option		alsa-mixer-control	`alsa` mixer control, e.g. `PCM`, `Master` or similar. Defaults to `PCM`.	NAME
Option		alsa-mixer-device	`alsa` mixer device, e.g `hw:0` or similar from `aplay -l`. Defaults to `--device` if specified, `default` otherwise.	DEVICE
Option		alsa-mixer-index	`alsa` mixer index, Index of the cards mixer. Defaults to `0`.	NUMBER
Option		initial-volume	Initial volume in % from 0-100. Default for softvol: `50`. For the `alsa` mixer: the current volume.	VOLUME
Option		zeroconf-port	The port the internal server advertises over zeroconf: `1` - `65535`. Ports <= `1024` may require root privileges.	PORT
Option	i	zeroconf-interface	Comma-separated interface IP addresses on which zeroconf will bind (Example `"192.168.0.10,10.0.0.10"`). Defaults to all interfaces. Ignored by DNS-SD.	IP
Flag		enable-volume-normalisation	Enables volume normalisation for librespot
Option		normalisation-method	Specify the normalisation method to use: `basic`, `dynamic`. Defaults to `dynamic`.	METHOD
Option		normalisation-gain-type	Specify the normalisation gain type to use: `track`, `album`, `auto`. Defaults to `auto`.	TYPE
Option		normalisation-pregain	Pregain (dB) applied by the normalisation. Defaults to `0`.	PREGAIN
Option		normalisation-threshold	Threshold (dBFS) to prevent clipping. Defaults to `-2.0`.	THRESHOLD
Option		normalisation-attack	Attack time (ms) in which the dynamic limiter is reducing gain. Defaults to `5`.	TIME
Option		normalisation-release	Release or decay time (ms) in which the dynamic limiter is restoring gain. Defaults to `100`.	TIME
Option		normalisation-knee	Knee steepness of the dynamic limiter. Default is `1.0`.	KNEE
Option		volume-ctrl	Volume control type `cubic`, `fixed`, `linear`, `log`. Defaults to `log`.	VOLUME_CTRL
Option		volume-range	Range of the volume control (dB). Default for softvol: `60`. For the `alsa` mixer: what the control supports.	RANGE
Flag		autoplay	Autoplay similar songs when your music ends.
Flag		disable-gapless	Disables gapless playback by forcing the sink to close between tracks.
Flag		passthrough	Pass a raw stream to the output. Only works with the pipe and subprocess backends.

Option or Flags marked with *unreleased are as of yet not a part of a librespot release and exist only in builds of the development (dev) branch. To see the Options and Flags available for your version run librespot -h.

Any cli argument you can pass to librespot can also be passed as an environment variable by prefixing it with LIBRESPOT_, making it all caps and replacing any -'s with _'s. So an option foo-bar would become the environment variable LIBRESPOT_FOO_BAR.

Removed Options

Removed	Replacement
mixer-card	alsa-mixer-device
mixer-index	alsa-mixer-index
mixer-name	alsa-mixer-control

Volume normalisation

librespot supports ReplayGain volume normalisation, with the ReplayGain values provided by Spotify in the Ogg streams. There are two types of volume normalisation methods available:

Dynamic

The volume is increased or decreased as per the average ReplayGain of that track or its album. However, if this now results in peaks over the threshold, the gain is dynamically reduced for the duration of that peak, then recovered to the original target gain. This length of the attack and release for this reduction and recovery from zero to full effect by default mimic the Spotify client, and are configurable.

During the attack and release period, the rate of change from zero to full effect (the "knee") has a configurable steepness. By default this is 1.0, which means a linear slope. Values above 1.0 yield softer knees with a more gentle start and end but steeper rate of change mid-way. Values below 1.0 start and stop more sharply, and are flatter in between. Values of 0.0 and below first give an impulse response, then invert the limiter, and should not be used.

Basic

The volume is increased or decreased as per the average ReplayGain of that track or its album. If that would result in peaks over a certain threshold. This gain is fixed for the entire duration of the track. This mode may be deprecated in a future release.

The equivalent librespot options to match the volume normalisation settings in official Spotify clients are:

Loud

--enable-volume-normalisation --normalisation-pregain 3

Normal (Default)

--enable-volume-normalisation --normalisation-pregain 0

Quiet

--enable-volume-normalisation --normalisation-pregain -9

Output format

librespot outputs 16-bit by default, but can be configured to output 64-bit floating point (F64), 32-bit floating point (F32), 32-bit integer (S32), 24-bit PCM in a 32-bit word (S24) or 24-bit integer packed as three bytes (S24_3). Software volume control and normalisation is done before sample conversion, so that there is no loss of dynamic range.

Mixer

By default, volume control will be done using the software volume mixer.

softvol and the rest of the audio sample pipeline completely works in 64-bit floating point. While some audiophiles may prefer to do volume control in hardware, a 64-bit pipeline is completely transparent and quite likely better than the 32-bit signed integer many hardware DACs work in.

There may be other valid reasons to use the alsa mixer, however:

Keeping the current playback volume instead of overwriting it with initial-volume (this is especially useful when you are switching back and forth librespot and other audio renderers).
Latching off the mute / unmute switch; librespot will toggle mute on hardware devices that support it when volume is dialed back to 0.

For the purists, you can use --mixer softvol --volume-ctrl fixed --initial-volume 100 to completely bypass volume control.

Volume control

The cubic volume control scale is available on both the softvol and alsa mixers. Cubic is like log, but has a bit more fine-grained control in the upper volume range. The specifics are documented here.

Note that just setting --backend alsa still uses librespot softvol. You also need to set --mixer alsa if you want to have volume control done by Alsa or in hardware. Note that softvol is recommended unless you have specific requirements, as softvol works in 64-bit floating point which is better than most hardware implementations, even if you have a 32-bit DAC.

Dithering

librespot supports dithering to lower the requantisation errors, that is caused by converting digital (ones and zeroes) to analog audio (continuous waveforms). Doing so lowers distortion and improves audio quality.

On S24, S24_3 and S24, the default is to use triangular dithering. Depending on personal preference you may use Gaussian dithering instead; it's not as good objectively, but it may be preferred subjectively if you are looking for a more "analog" sound akin to tape hiss.
Advanced users who know that they have a DAC without noise shaping have a third option: high-passed dithering, which is like triangular dithering except that it moves dithering noise up in frequency where it is less audible. Note: 99% of DACs are of delta-sigma design with noise shaping, so unless you have a multibit / R2R DAC, or otherwise know what you are doing, this is not for you.
Don't dither or shape noise on S32, F32, or F64. On F32 and F64 it's not supported anyway (there are no integer conversions and so no rounding errors) and on S32 the noise level is so far down that it is simply inaudible even after volume normalisation and control.