alsaucm (1) - Linux Manuals

alsaucm: ALSA Use Case Manager


alsaucm - ALSA Use Case Manager


alsaucm <options> [command]


alsaucm (ALSA Use Case Manager) is a program to use the ALSA Use Case Interface from the command line.

On complex sound cards, setting up audio routes is not trivial and mixer settings can conflict one another preventing the audio card to work at all.

The ALSA Use Case Manager is a mechanism for controlling complex audio hardware establishing a relationship between hardware configurations and meaningful use cases that the end-user can relate with.

The use case manager can also be used to switch between use cases when necessary, in a consistent way.

At a lower level, the use case manager works by configuring the sound card ALSA kcontrols to change the hardware digital and analog audio routing to match the requested device use case.

The use case manager kcontrol configurations are stored in easy to modify text files. An audio use case can be defined by a verb and device parameter.

The verb describes the use case action i.e. a phone call, listening to music, recording a conversation etc. The device describes the physical audio capture and playback hardware i.e. headphones, phone handset, bluetooth headset, etc.


Available options:

-h, --help
this help
-c, --card NAME
open card NAME
-i, --interactive
interactive mode
-b, --batch FILE
batch mode (use '-' for the stdin input)
-n, --no-open
do not open first card found

Available commands:

open NAME
open card NAME.

valid names are sound card names as listed in /usr/share/alsa/ucm.

reset sound card to default state.
reload configuration.
list available cards.
list command, for items returning two entries (value+comment).

the value of the IDENTIFIER argument can can be:

_verbs - get verb list (in pair verb+comment)
_devices[/{verb}] - get list of supported devices (in pair device+comment)
_modifiers[/{verb}] - get list of supported modifiers (in pair modifier+comment)

The forms without the trailing /{verb} are valid only after a specific verb has been set.

list command, for lists returning one item per entry.

the value of the IDENTIFIER argument can vary depending on the context, it can be:

TQ[/{verb}] - get list of Tone Quality identifiers
_enadevs - get list of enabled devices
_enamods - get list of enabled modifiers
_supporteddevs/{modifier}|{device}[/{verb}] - list of supported devices
_conflictingdevs/{modifier}|{device}[/{verb}] - list of conflicting devices
get string value.

the value of the IDENTIFIER argument can can be:

_verb - return current verb
[=]{NAME}[/[{modifier}|{/device}][/{verb}]] (For valid NAMEs look at the ALSA Use Case Interface)
get integer value.

the value of the IDENTIFIER argument can can be:

set string value

The value of the IDENTIFIER argument can can be:

_verb - set the verb to VALUE
_enadev - enable the device specified by VALUE
_disdev - disable the device specified by VALUE
_swdev/{old_device} - switche device:
disable old_device and then enable the device specified by VALUE
if no device was enabled just return
_enamod - enable the modifier specified by VALUE
_dismod - disable the modifier specified by VALUE
_swmod/{old_modifier} - switch modifier:
disable old_modifier and then enable the modifier specified by VALUE
if no modifier was enabled just return

Note that the identifiers referring to devices and modifiers are valid only after setting a verb.

h, help
q, quit


The master use case files for each supported sound card are in /usr/share/alsa/ucm.

For example, the master use case file for the Pandaboard card is in /usr/share/alsa/ucm/PandaBoard/PandaBoard.conf, this file lists all the supported use cases, e.g.

SectionUseCase."HiFi" {
                File "hifi"
                Comment "Play HiFi quality Music."

Each use case defines a _verb, which is described in the file specified in the File directive, like above.

The HiFi verb above is described in /usr/share/alsa/ucm/PandaBoard/hifi.

For more details on the syntax of UCM files, see the alsa-lib source code:;a=blob;f=src/ucm/parser.c


Some commands, like for instance list _devices, can only work after setting a _verb in the same execution, for instance this sequence doesn't work:

# alsaucm -c bytcr-rt5640 set _verb HiFi
# alsaucm -c bytcr-rt5640 list _devices

However this command does:

# alsaucm -n -b - <<EOM
open bytcr-rt5640
set _verb HiFi
list _devices

An example of setting the Speaker device for the HiFi verb of the bytcr-rt5640 card:

# alsaucm -n -b - <<EOM
open bytcr-rt5640
set _verb HiFi
set _enadev Speaker


None known.


Antonio Ospite <ao2 [at]>