Current File : //usr/share/doc/alsa-lib-1.1.8/asoundrc.txt
# Configuration file syntax
# Include a new configuration file
<filename>
# Simple assign
name [=] value [,|;]
# Compound assign (first style)
name [=] {
name1 [=] value [,|;]
...
}
# Compound assign (second style)
name.name1 [=] value [,|;]
# Array assign (first style)
name [
value0 [,|;]
value1 [,|;]
...
]
# Array assign (second style)
name.0 [=] value0 [,|;]
name.1 [=] value1 [,|;]
# ******************************************************************************
# Server definition
server.NAME {
host STR # host where the server is located (if map to local address
# server is local, and then it may be started automatically)
[socket STR] # PF_LOCAL socket name to listen/connect
[port INT] # PF_INET port number to listen/connect
}
# PCM type definition
pcm_type.NAME {
[lib STR] # Library file (default libasound.so)
[open STR] # Open function (default _snd_pcm_NAME_open)
[redirect { # Redirect this PCM to an another
[filename STR] # Configuration file specification
name STR # PCM name specification
}]
}
# PCM scope type definition
pcm_scope_type.NAME {
[lib STR] # Library file (default libasound.so)
[open STR] # Open function (default _snd_pcm_scope_NAME_open)
}
# PCM scope definition
pcm_scope.NAME {
type STR # Scope type
...
}
# Slave PCM definition
pcm_slave.NAME {
pcm STR # PCM name
# or
pcm { } # PCM definition
format STR # Format
channels INT # Channels
rate INT # Rate
period_time INT # Period time
buffer_time INT # Buffer time
etc.
}
# Hook arguments definition
hook_args.NAME {
... # Arbitrary arguments
}
# PCM hook type
pcm_hook_type.NAME {
[lib STR] # Library file (default libasound.so)
[install STR] # Install function (default _snd_pcm_hook_NAME_install)
}
# PCM hook definition
pcm_hook.NAME {
type STR # PCM Hook type (see pcm_hook_type)
[args STR] # Arguments for install function (see hook_args)
# or
[args { }] # Arguments for install function
}
# PCM definition
pcm.NAME {
type STR # Type
[comment ANY] # Saved comments
# PCM types:
type hw # Kernel PCM
card INT/STR # Card name or number
[device] INT # Device number (default 0)
[subdevice] INT # Subdevice number, -1 first available (default -1)
mmap_emulation BOOL # enable mmap emulation for ro/wo devices
type hooks # PCM with hooks
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
}
hooks {
ID STR # Hook name (see pcm_hook)
# or
ID { } # Hook definition (see pcm_hook)
}
type plug # Format adjusted PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
[format STR] # Slave format (default nearest) or "unchanged"
[channels INT] # Slave channels (default nearest) or "unchanged"
[rate INT] # Slave rate (default nearest) or "unchanged"
}
route_policy STR # route policy for automatic ttable generation
# STR can be 'default', 'average', 'copy', 'duplicate'
# average: result is average of input channels
# copy: only first channels are copied to destination
# duplicate: duplicate first set of channels
# default: copy policy, except for mono capture - sum
ttable { # Transfer table (bidimensional compound of
# cchannels * schannels numbers)
CCHANNEL {
SCHANNEL REAL # route value (0.0 ... 1.0)
}
}
type copy # Copy conversion PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
}
type linear # Linear format conversion PCM
type adpcm # IMA-ADPCM format conversion PCM
type alaw # A-Law format conversion PCM
type mulaw # Mu-Law format conversion PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
format STR # Slave format
}
type rate # Rate conversion PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
[format STR] # Slave format (default client format)
rate INT # Slave rate
}
type route # Attenuated static route PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
[format STR] # Slave format (default client format)
[channels INT] # Slave channels (default client channels)
}
ttable { # Transfer table (bidimensional compound of
# cchannels * schannels numbers)
CCHANNEL {
SCHANNEL REAL # route value (0.0 ... 1.0)
}
}
type multi # Linked PCMs (exclusive access to selected channels)
slaves { # Slaves definitions
ID STR # Slave name for slave N (see pcm_slave)
# or
ID { # Slave definition for slave N
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
channels INT # Slave channels
}
}
bindings { # Bindings table
N { # Binding for client channel N
slave STR # Slave key
channel INT # Slave channel
}
}
[master INT] # Define the master slave
type file # File plugin
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
}
file STR # File name
# or
file INT # File descriptor
[format STR] # File format (NYI)
[perm INT] # File permission (default 0600)
type meter # Meter PCM
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition or name
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
}
[frequency INT] # Updates per second
scopes { # Scopes
ID STR # Scope name (see pcm_scope)
# or
ID { } # Scope definition (see pcm_scope)
}
type droute # Attenuated dynamic route PCM (NYI)
slave STR # Slave name (see pcm_slave)
# or
slave { # Slave definition
pcm STR # Slave PCM name
# or
pcm { } # Slave PCM definition
[format STR] # Slave format (default client format)
[channels INT] # Slave channels (default client channels)
}
ctl STR # Ctl name
bindings { # Bindings table
ID { # Binding entry
cchannels { # Client channels
C INT # Client channel
}
schannel { # Slave channels
S INT # Slave channel
}
control STR # Control name of C * S (or C values: only if C == S)
}
}
type null # Null endpoint plugin
[time INT] # Time related or not (NYI)
type shm # Shared memory client PCM
server STR # Server name
pcm STR # PCM name on server
type share # Share PCM
slave STR # Slave name (see pcm_slave)
bindings { # Bindings table
N INT # Slave channel for client channel N
}
type mix # Mix PCM
slave STR # Slave name (see pcm_slave)
bindings { # Bindings table
N INT # Slave channel for client channel N
}
type ladspa # LADSPA plugin PCM
slave STR # Slave name (see pcm_slave)
path STR # Path or paths (delimited with ':')
plugins | playback_plugins | capture_plugins {
N { # Configuration for LADSPA plugin N
id # # LADSPA plugin ID (for example 1043)
label STR # LADSPA plugin label (for example 'delay_5s')
filename STR # Full filename of .so library with LADPA plugin code
policy STR # Policy can be 'none' or 'duplicate'
input | output {
bindings {
C INT or STR # C - channel, INT - audio port index, STR - audio port name
}
controls {
I INT or REAL # I - control port index, INT or REAL - control value
}
}
}
}
type dmix # Direct mixing plugin
slave STR # Slave name (see pcm_slave)
ipc_key INT # Unique ipc key
ipc_perm INT # ipc permissions (default 0600)
ipc_gid INT # ipc gid (default -1 = disable)
ipc_key_add_uid BOOL # Add current uid to ipc_key
bindings { # Bindings table
N INT # Slave channel for client channel N
}
type dsnoop # Direct snoop (split one capture stream to more)
slave STR # Slave name (see pcm_slave)
ipc_key INT # Unique ipc key
ipc_perm INT # ipc permissions (default 0600)
ipc_gid INT # ipc gid (default -1 = disable)
ipc_key_add_uid BOOL # Add current uid to ipc_key
bindings { # Bindings table
N INT # Slave channel for client channel N
}
type dshare # Share channels from one stream
slave STR # Slave name (see pcm_slave)
ipc_key INT # Unique ipc key
ipc_perm INT # ipc permissions (default 0600)
ipc_gid INT # ipc gid (default -1 = disable)
ipc_key_add_uid BOOL # Add current uid to ipc_key
bindings { # Bindings table
N INT # Slave channel for client channel N
}
}
# CTL type definition
ctl_type.NAME {
[lib STR] # Library file (default libasound.so)
[open STR] # Open function (default _snd_ctl_NAME_open)
}
# CTL definition
ctl.NAME {
type STR # Type
[comment ANY] # Saved comments
# CTL types
type hw
card STR/INT # Card name or number
type shm # Shared memory client CTL
server STR # Server name
ctl STR # CTL name on server
}
# RAWMIDI type definition
rawmidi_type.NAME {
[lib STR] # Library file (default libasound.so)
[open STR] # Open function (default _snd_rawmidi_NAME_open)
}
# RAWMIDI definition
rawmidi.NAME {
type STR # Type
[comment ANY] # Saved comments
# RAWMIDI types:
type hw # Kernel RAWMIDI
card INT/STR # Card name or number
[device] INT # Device number (default 0)
[subdevice] INT # Subdevice number, -1 first available (default -1)
}
# SEQ type definition
seq_type.NAME {
[lib STR] # Library file (default libasound.so)
[open STR] # Open function (default _snd_seq_NAME_open)
}
# SEQ definition
seq.NAME {
type STR # Type
[comment ANY] # Saved comments
# SEQ types:
type hw # Kernel SEQ
}
# Aliases
DEF.NAME1 NAME2 # DEF.NAME1 is an alias for DEF.NAME2
Some examples:
pcm.trident {
type hw
card 0
device 0
}
pcm.ice1712 {
type hw
card 1
device 0
}
pcm.ice1712_spdif {
type plug
ttable.0.8 1
ttable.1.9 1
slave.pcm ice1712
}
pcm_slave.rs {
pcm trident
rate 44100
}
pcm.r {
type rate
slave rs
}
pcm.m {
type meter
slave.pcm plug:trident
frequency 50
scopes [
{
type level
}
]
}
pcm_scope_type.level {
lib /home/abramo/scopes/scope-level.so
}
# an example command is 'aplay -D plug:ladspa <filename>'
# otherwise, the ladspa plugin expects FLOAT type which
# is very rare
pcm.ladspa {
type ladspa
slave.pcm "plughw:0,0";
path "/home/perex/src/ladspa_sdk/plugins";
plugins [
{
label delay_5s
input {
controls [ 0.8 0.2 ]
}
}
]
}
# an example command for dmix plugin to force 44100Hz mixing rate:
# aplay -D"plug:'dmix:RATE=44100'" <filename>
# an example command for dmix plugin to force 44100Hz and hw:1,0 output device
# aplay -Dplug:\'dmix:SLAVE=\"hw:1,0\",RATE=44100\' <filename>
# an example command for dmix plugin to force 32-bit signed little endian format
# aplay -D"plug:'dmix:FORMAT=S32_LE'" <filename>
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