Author: | Antonio Ospite <ao2@ao2.it> |
---|---|
Date: | 2016-09-22 |
Copyright: | GPLv2+ |
Manual section: | 1 |
Manual group: | General Commands Manual |
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
NAMEopen card NAME.
valid names are sound card names as listed in
/usr/share/alsa/ucm
.reset
- reset sound card to default state.
reload
- reload configuration.
listcards
- list available cards.
list
IDENTIFIERlist 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.list1
IDENTIFIERlist 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 devicesget
IDENTIFIERget 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)geti
IDENTIFIERget integer value.
the value of the IDENTIFIER argument can can be:
_devstatus/{device}
_modtstaus/{device}
set
IDENTIFIER VALUEset 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
- help
q
,quit
- 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: http://git.alsa-project.org/?p=alsa-lib.git;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 EOM
An example of setting the Speaker device for the HiFi verb of the bytcr-rt5640 card:
# alsaucm -n -b - <<EOM open bytcr-rt5640 reset set _verb HiFi set _enadev Speaker EOM
None known.