PipeWire Pulseaudio modules

DESCRIPTION

PipeWire's Pulseaudio emulation implements several Pulseaudio modules. It only supports its own built-in modules, and cannot load external modules written for Pulseaudio.

Loading modules

The built-in modules can be loaded using Pulseaudio client programs, for example pactl load-module <module-name> <module-options>. They can also added to pipewire-pulse.conf, typically by a drop-in file in ~/.config/pipewire/pipewire-pulse.conf.d/ containing the module name and its arguments

pulse.cmd = [
    { cmd = "load-module" args = "module-null-sink sink_name=foo" flags = [ ] }
]

To list all modules currently loaded, with their arguments:

pactl list modules

For a short list of loaded modules:

pactl list modules short

Modules may be unloaded using either the module-name or index number:

pactl load-module <module-name> <parameters>

pactl unload-module <module-name|index#>

Common module options

Most modules that create streams/devices support the following properties:

sink_name, source_name

Name for the sink (resp. source). Allowed characters in the name are a-z, A-Z, numbers, period (.) and underscore (_). The length must be 1-128 characters.

format

The sample format. The supported audio formats are:

PCM

u8: unsigned 8-bit integer
aLaw: A-law encoded 8-bit integer
uLaw: μ-law encoded 8-bit integer
s16le: signed 16-bit little-endian integer
s16be: signed 16-bit big-endian integer
s16, s16ne: native-endian aliases for s16le or s16be
s16re: reverse-endian alias for s16le or s16be
float32le: 32-bit little-endian float
float32be: 32-bit big-endian float
float32, float32ne: native-endian aliases for float32le or float32be
float32re: reverse-endian alias for float32le or float32be
s32le: signed 32-bit little-endian integer
s32be: signed 32-bit big-endian integer
s32, s32ne: native-endian aliases for s32le or s32be
s32re: reverse-endian alias for s32le or s32be
s24le: signed 24-bit little-endian integer (note: ALSA calls this "S24_3LE")
s24be: signed 24-bit big-endian integer (note: ALSA calls this "S24_3BE")
s24, s24ne: native-endian aliases for s24le or s24be
s24re: reverse-endian alias for s24le or s24be
s24-32le: signed 24-bit little-endian integer, packed into a 32-bit integer so that the 8 most significant bits are ignored (note: ALSA calls this "S24_LE")
s24-32be: signed 24-bit big-endian integer, packed into a 32-bit integer so that the 8 most significant bits are ignored (note: ALSA calls this "S24_BE")
s24-32, s24-32ne: native-endian aliases for s24-32le or s24-32be
s24-32re: reverse-endian alias for s24-32le or s24-32be

Compressed audio formats

Below is a list of all supported compressed formats. The code at the beginning of each line is used whenever a textual identifier for a format is needed (for example in configuration files or on the command line). The formats whose identifier ends with -iec61937 have to be wrapped in IEC 61937 frames, which makes the compressed audio behave more like normal PCM audio.

ac3-iec61937: Dolby Digital (DD / AC-3 / A/52)
eac3-iec61937: Dolby Digital Plus (DD+ / E-AC-3)
mpeg-iec61937: MPEG-1 or MPEG-2 Part 3 (not MPEG-2 AAC)
dts-iec61937: DTS
mpeg2-aac-iec61937: MPEG-2 AAC (supported since PulseAudio 4.0)
truehd-iec61937: Dolby TrueHD (added in PulseAudio 13.0, but doesn't work yet in practice)
dtshd-iec61937: DTS-HD Master Audio (added in PulseAudio 13.0, but doesn't work yet in practice)
pcm: PCM (not a compressed format, but listed here, because pcm is one of the recognized encoding identifiers)
any: (special identifier for indicating that any encoding can be used)

rate

The sample rate.

channels

Number of audio channels.

channel_map

A channel map. A list of comma-separated channel names. The currently defined channel names are: left, right, mono, center, front-left, front-right, front-center, rear-center, rear-left, rear-right, lfe, subwoofer, front-left-of-center, front-right-of-center, side-left, side-right, aux0, aux1 to aux15, top-center, top-front-left, top-front-right, top-front-center, top-rear-left, top-rear-right, top-rear-center

sink_properties, source_properties

Set additional properties of the sink/source. For example, you can set the description directly when the module is loaded by setting this parameter.

load-module module-alsa-sink sink_name=headphones sink_properties=device.description=Headphones

BUILT-IN MODULES

AUTHORS

The PipeWire Developers <https://gitlab.freedesktop.org/pipewire/pipewire/issues>; PipeWire is available from <https://pipewire.org>