Ecasound library contains an interpreter module that understands
a set of commands aimed at controlling various library services.
This is called the ecasound interactive mode (EIAM). All programs
linked to ecasound library can use this facility.
ECI API and return types
A special case of interactive mode use is ecasound's control interface (ECI),
which is a small library providing easy access to the interactive
mode commands from outside of libecasound. When issuing inter commands using
the control interface, it's possible that commands also return information.
Currently supported return value types are: string [s], list of strings [S]
(elements separated by commas; escaped if necessary), integer [i],
long integer [li] and floating-point number [f]. These definitions are
used throughout this document. Commands that return nothing (void) are
marked with [-]. Additionally, return type [e] marks an error condition.
When an interactive mode command results in an error, an error string
explaining the condition is returned.
Limitations related to real-time control and modifications
It's not possible to use all interactive mode commands to modify and
control objects that belong to a connected chainsetup. Ecasound will automatically
disconnect (and later try to reconnect) the chainsetup in case these commands
are received while connected. Commands that have this limitation are:
The following commands may be used on with a connected chainsetup,
but they require pausing the engine temporarily (if running) and this
can cause audible gaps to playback and recording. In practise
this means it is currently not possible to add or remove chain
operators in a gapless/seamless fashion. The affected commands:
cop-add,
ctrl-add,
The following commands can be used on a connected chainsetup
and when the engine is running (not a complete list but at
least these commands are supported):
Quit ecasound session. What this means in practice depends on the
client implementation. In ecasound interactive mode, 'quit' terminates
the ecasound process. When sent over ecasound server connection (aka
NetECI), 'quit' terminates the active network connection, but does not
terminate the ecasound server process. [-]
start, t
Processing is started (play). Error string is return if any errors upon
startup are encountered. [e]
stop, s
Stop processing. [-]
stop-sync, s
Stop processing with a blocking call (do not return until engine has
actually stopped). [-]
run
Like 'start' but blocks until processing is finished. Error string
is return if any errors upon startup, or during process, are
encountered. [e]
debug 'debug-level'
Set debug level to 'debug-level'. Notice that client programs can
reimplement the debug routines. [-]
resource-file 'path-to-file'
Overrides the global and user resource files. Does not affect
already created objects. This command is equivalent to '-R' ecasound
option (see ecasound (1) man page).
-prefix:arg1,...,argN
Equivalent to issuing 'cs-option -prefix:arg1,...,argN). See documentation
for 'cs-option'.
help', 'h'
Help! [-]
GLOBAL
engine-status
Returns a string describing the engine status (running, stopped,
finished, error, not ready). See also cs-status. [s]
engine-launch
Starts the real-time engine. Engine will execute the currently
connected chainsetup (see 'cs-connect). This action does not yet
start actual processing (see start and stop). When
ecasound is used as a JACK client, issuing engine-launch
makes ecasound an active JACK client (i.e. ecasound's ports
can be connected to other JACK clients). [-]
engine-halt
Stops the engine. Does not disconnect the chainsetup that
was running. See also cs-disconnet and stop. When
ecasound is used as a JACK client, engine-halt will
cause ecasound to become a deactivated client (all JACK
connections are torn down). [-]
CHAINSETUPS
Chainsetup is the central data object. All other objects (inputs,
outputs, chains, etc) are connected to some chainsetup. There can be
many chainsetups but only one can be connected. Similarly only
one chainsetup can be selected. If not otherwise specified operations
are done on the selected chainsetup. Some operations also require
that selected chainsetup is not connected.
cs-add 'name'
Adds a new chainsetup with name 'name'. 'name' is now
the selected chainsetup. [-]
cs-remove
Removes currently selected chainsetup. [-]
cs-list
Returns a list of all chainsetups. [S]
cs-select 'name'
Selects chainsetup 'name'. [-]
cs-selected
Returns the name of currently selected chainsetup. [s]
cs-index-select 'cs_index', cs-iselect 'cs_index'
Selects a chainsetup based on a short index string. Chainsetup names
can be rather long. This command can be used to avoid typing
these long names. 'cs_index' is an integer value, where '1' refers to
the first audio input/output. You can use 'cs-list' and 'cs-status'
to get a full list of currently available chainsetups. [-]
cs-load 'filename'
Adds a new chainsetup by loading it from file 'filename'.
'filename' is now the selected chainsetup. [-]
cs-save
Saves the currently selected chainsetup to file. If chainsetup was loaded
from a file, the saved version will replace the original. If it doesn't
have a default filename, it's saved to "chainsetup_name.ecs". [-]
cs-save-as 'filename'
Saves currently selected chainsetup to file 'filename'. [-]
cs-edit
Currently selected chainsetup is saved to a temporary file. This
file is loaded to an external editor (see ecasoundrc (5)). After
editing, the chainsetup is loaded back to ecasound. [-]
cs-is-valid
Whether currently selected chainsetup is valid (=can be connected)? [i]
cs-connect
Connect currently selected chainsetup to engine. When connecting,
all resources (e.g. files, soundcard devices, external programs) needed
to execute the chainsetup are reserved. Only one chainsetup can be connected
at a time. Error string is returned if connection fails (for instance
due to error in allocating the resources). [e]
cs-disconnect
Disconnect currently connected chainsetup. This action will free
all external resources needed by the chainsetup. [-]
cs-connected
Returns the name of currently connected chainsetup. [s]
Rewinds the current chainsetup position by 'time-in-seconds' seconds.
Position of all inputs and outputs attached to the selected chainsetup
is also affected. [-]
The current chainsetup position is forwarded by 'time-in-seconds'
seconds. Position of all inputs and outputs attached to the selected chainsetup
is also affected. [-]
Sets the chainsetup position to 'time-in-seconds' seconds from the
beginning. Position of all inputs and outputs attached to the selected
chainsetup is also affected. [-]
cs-set-position-samples 'time-in-samples'
Sets the chainsetup position to 'time-in-samples' samples from the
beginning. Position of all inputs and outputs attached to the selected
chainsetup is also affected. [-]
cs-get-position, cs-getpos, getpos, get-position
Returns the current chainsetup position in seconds. [f]
cs-get-position-samples
Returns the current chainsetup position in samples. [li]
cs-get-length, get-length
Returns the chainsetup length in seconds (if known). [f]
cs-get-length-samples, get-length-samples
Returns the chainsetup length in samples (if known). [li]
cs-set-length 'seconds'
Sets processing time in seconds (doesn't have to be an integer value).
A special-case value of '-1' will set the chainsetup length
according to the longest input object. [-]
cs-set-length-samples 'samples'
Sets processing time in samples. [-]
cs-toggle-loop
Toggle looping. When processing is finished, engine will start
again from the initial position. It's not always possible to enable looping
(for instance all inputs and outputs have infinite length and
chainsetup length is not explicitly set with 'cs-set-length'). [-]
cs-set-param
Interpret general chainsetup parameters like for example
"-b" (buffersize), "-n" (name), etc. See ecasound (1) for
more info. [-]
cs-set-audio-format 'bits,channels,sample_rate'
Set the default sample parameters for currently selected chainsetup.
For example cd-quality audio would be "16,2,44100". This does the
same as command-line argument "-f" (see ecasound (1)). [-]
cs-status, status, st
Prints out status information about available chainsetup.
Detailed information is printed out for connected (=available
for running) nd selected (=available for editing) chainsetups.
Other chainsetups are listed, but further details are
suppressed. To get full details of a specific chainsetup,
select it with 'cs-select' or 'cs-iselect', and then
issue 'cs-select'. [s]
cs-option '-prefix:arg1,...,argN'
One powerful feature of the interactive-mode is that it
provides full access to ecasound's command-line syntax.
For instance, command "cs-option -efb:400,200" means that
a bandpass filter is added to the currently selected
chain, with initial parameters 400 (center frequency)
and 200 (width in Hz).
Note that session level options (such as setting debug level)
can not be used with 'cs-option' (i.e. only options that modify
chainsetups).
Note! Ecasound interactive mode implicitly interprets all strings
beginning with a '-' as "cs-option string".
CHAINS
Chain is a simple signal flow abstraction. Every chain has one input
and one output. All chain operators and their controllers are attached
to chains. Chains can be muted, unmuted and be bypassed. If not
otherwise stated, all operations are done to currently selected
chainsetup.
c-add 'cname1,...,cnameN'
Adds a set of chains. Added chains are automatically selected. Note
that commas in chain names are not allowed. [-]
c-remove
Removes selected chains. [-]
c-list
Returns a list of all chains. [S]
c-select 'cname1,...,cnameN'
Selects chains. Other chains are automatically deselected. [-]
Selects a set of chains based on the list of indixes. Each index is
an integer value, where '1' refers to the first chain. You can use
'c-list' and 'c-status' to get a full list of currently available
chains. [-]
c-select-all
Selects all chains. [-]
c-select-add 'cname1,...,cnameN'
Selects more chains. [-]
c-deselect 'cname1,...,cnameN'
Deselects chains. [-]
c-selected
Returns a list of selected chains. [S]
c-clear
Clear selected chains by removing all chain operators and controllers.
Doesn't change how chains are connected to inputs and outputs. [-]
c-rename 'new_name'
Renames the selected chain. When using this command, exactly one chain must
be selected. [-]
c-mute <on|off|toggle>
Set the mute state of the currently selected chain. When chain is muted,
it will only output silence.
The command takes a single parameter: "on" -> chain is muted,
"off" -> not muted, and "toggle" -> change the muting state.
If parameter is omitted, "toggle" is assumed (muting is either
enabled or disabled, depending on previous state).
Control of chain and chain operator muting states is independent.
If "c-mute off" is executed, the states of individual cop-bypass
commands will take effect. If chain is muted, the chain will
output silence irrespective of the individual chain operator
muting state. [-]
c-bypass <on|off|toggle>
Set the bypass state of the currently selected chain. When chain is bypassed,
sample data is passed through unprocessed (all chain operators are disabled
for the given chain).
The command takes a single parameter: "on" -> chain is bypassed,
"off" -> no bypass, and "toggle" -> change the bypass state.
If parameter is omitted, "toggle" is assumed (bypass is either
enabled or disabled, depending on previous state).
Control of chain and chain operator bypass states is independent.
If chain bypass is disabled, the states of individual cop-bypass
commands will take effect. If chain is bypassed, all operators are
bypassed independetly of their cop-bypass state. [-]
c-status, cs
Print status info about all chains. [s]
c-is-bypassed
Returns true if selected chain is currently bypassed (none of
the chain operators are run). See 'c-bypass'. [i]
c-is-mute
Returns true if selected chain is currently muted (outputs
silence as its output). See 'c-mute'. [i]
AUDIO INPUT/OUTPUT OBJECTS
If not otherwise stated, all operations are done to currently selected
object. All commands with ai- prefix operate on audio inputs,
while commands with ao- operate on outputs.
ai-add 'input_format_string'
Adds a new input object. See ecasound (1) man page for more info about
the argument format ('-i' option). Note on syntax: if any of
the parameters (such as a filename) contains commas, the parameter
should be enclosed in double-quotes. [-]
ao-add 'output_format_string'
Adds a new output object. See ecasound (1) man page for more info about
the argument format ('-o' option). If argument is omitted,
a default output device is added (see ecasoundrc (5)). Note on syntax: if any
of the parameters (such as a filename) contains commas, the parameter
should be enclosed in double-quotes. [-]
ao-add-default
Adds the default output device (see ecasoundrc (5)). [-]
ai-describe, ao-describe
Returns a Ecasound Option Syntax (EOS) compliant string
describing the input/output. See the Ecasound User's Guide
for more information about EOS. This command was introduced in
ecasound 2.4.4. [s]
Selects an audio object. 'aobject_name' refers to the string
used when creating the object (the first argument given to ai-add/ao-add).
Note that as a important difference to ai-add/ao-add, one should not
enclose the object name in double quotes for ai-select/ao-select. In the
case a chainsetup contains multiple inputs, or outputs, with
identical name, 'ai-select' and 'ao-select' will select
the first matching instance. In order to select a specific
instance, the 'ai-iselect' and 'ao-iselect' commands need to
be used. [-]
Select some audio object based on a short index string. Especially file
names can be rather long. This command can be used to avoid typing
these long names when selecting audio objects. 'aobject_index' is
an integer value, where '1' refers to the first audio input/output.
You can use 'ai-list' and 'ao-list' to get a full list of currently
available inputs/outputs. [-]
ai-selected, ao-selected
Returns the name of the currently selected audio object. [s]
ai-attach, ao-attach
Attaches the currently selected audio object to all selected chains. [-]
ai-remove, ao-remove
Removes the currently selected audio object from the chainsetup. [-]
Returns the audio object position in samples. [li]
ai-get-length, ao-get-length
Returns the audio object length in seconds. [f]
ai-get-length-samples, ao-get-length-samples
Returns the audio object length in samples. [li]
ai-get-format, ao-get-format
Returns the audio format of the selected audio input/output as a
formatted string. See documentation for '-f' command-line option. [s]
ai-list, ao-list
Returns a list of all input/output objects. [S]
aio-register
Prints a list of registered audio object types. [s]
aio-status
Audio object status (index strings, position, length, etc). [s]
CHAIN OPERATORS
Chain operators are used to process and analyze sample data.
They are attached to chains. If not otherwise stated,
currently selected chainsetup and chain are used. Also,
'chainop_id' and 'param_id' are used to select chain operators
and their parameters. First valid value for these parameters
is 1.
cop-add 'cop_format_string'
Adds a new chain operator. In addition to normal chain operators,
this commmand can also be used to add effect presets and various
plugins. Note; it is not possible to add operators to multiple
chains at once. In other words only one chain should be selected
when issuing 'cop-add'. See ecasound (1) man page for more info. [-]
cop-bypass <on|off|toggle>
Set the bypass state of the currently selected chain operator.
The command takes a single parameter: "on" -> operator is bypassed,
"off" -> no bypass, and "toggle" -> change the bypass state.
If parameter is omitted, "toggle" is assumed (bypass is either
enabled or disabled, depending on previous state). [-]
cop-is-bypassed
Returns true if selected chain operator is currently bypassed
(temporarily not part of the processing chain). [i]
cop-describe
Returns a Ecasound Option Syntax (EOS) compliant string
describing the chain operator. See the Ecasound User's Guide
for more information about EOS. This command was introduced in
ecasound 2.4.4. [s]
cop-remove
Removes the selected chain operator. [-]
cop-list
Returns a list of all chain operators attached to the currently
selected chain. [S]
Returns the index number of currently selected chain operator. [i]
cop-set 'chainop_id,param_id,value'
Changes the value of a single chain operator parameter. Unlike other
chain operator commands, this can also be used during processing.
See also 'cop-get'. [-]
cop-get 'chainop_id,param_id'
Returns the current value of chain operator parameter identified by
'chainop_id' and 'param_id'. This command is a shorthand for
'cop-select chainop_id ; copp-iselect param_id ; copp-get'. [f]
cop-status
Returns info about chain operator status. [s]
copp-list
Returns a list of selected chain operator's parameters. [S]
Returns the index number of currently selected chain operator parameter. [i]
copp-set 'value'
Sets the selected parameter value to 'value'. [-]
copp-get
Returns the selected parameter value. See also 'cop-get'. [f]
cop-register
Prints a list of registered chain operators. [s]
preset-register
Prints a list of registered effect presets. [s]
ladspa-register
Prints a list of registered LADSPA plugins. [s]
CONTROLLERS
Controllers are used to control individual chain operator parameters.
They are attached to chains. If not otherwise stated, currently
selected chainsetup and chains are used.
ctrl-add 'copc_format_string'
Adds a new controller and attach it to currently selected chain
operator. The argument syntax is either "-<id_string>:par1,...,parN"
or just "<id_string>:par1,...,parN". If parameter itself contains
commas, the parameter should be enclosed in double-quotes.
See ecasound (1) man page for more info. [-]
ctrl-describe
Returns a Ecasound Option Syntax (EOS) compliant string
describing the controller. See the Ecasound User's Guide
for more information about EOS. This command was introduced in
ecasound 2.4.4. [s]
ctrl-remove
Removes the selected controller. [-]
ctrl-list
Returns a list of all controllers attached to the currently
selected chain. [S]
Returns the index number of currently selected controller. [i]
ctrl-status
Returns info about controller status. [s]
ctrl-register
Prints a list of registered controllers. [s]
ctrl-get-target
Returns the index number of the chain operator that is
connected to the selected controller. The returned index
refers to the currently selected chain (see 'cop-list'). [i]
ctrlp-list
Returns a list of all controller parameters. This command was introduced in
ecasound 2.4.2. [S]
ctrlp-select
Selects a controller parameter. This command was introduced in
ecasound 2.4.2. [-]
ctrlp-selected
Returns the index number of currently selected controller parameter. This command
was introduced in ecasound 2.4.2. [i]
ctrlp-get
Returns the selected controller parameter value. This command was introduced in
ecasound 2.4.2. [f]
ctrlp-set
Sets the selected controller parameter value to 'value'. This command was introduced in
ecasound 2.4.2. [-]
JACK CONNECTION MANAGEMENT
If Ecasound is compiled with support for JACK audio server,
the following set of commands is provided for controlling connections
between JACK ports.
jack-connect 'src-port' 'dest-port'
Make a connection between the two ports given as parameters. This command
is similar to the 'jack_connect' command line tool that is distributed
with JACK package. [-]
jack-disconnect 'src-port' 'dest-port'
Disconnect the two ports given as parameters. This command is similar
to the 'jack_disconnect' command line tool that is distributed
with JACK package. [-]
jack-list-connections
Returns a list of all JACK ports and a list of connections
for each port. This command is similar to the 'jack_lsp' command
line tool (e.g. 'jack_lsp -c') that is distributed with JACK package. [s]
INTERNAL COMMANDS
Internal commands are not directly aimed at normal use. They
are primarily meant for use in scripting and frontends.
int-cmd-list
Returns a list of all registered interactive mode commands. [S]
int-log-history
Returns recent log messages sent by libecasound modules. This
is a good tool for debugging ECI/EIAM scripts and applications. This
command was introduced in ecasound 2.4.0. [s]
int-output-mode-wellformed
Select the well-format output format for log messages. [-]
int-set-float-to-string-precision
Sets precision used in float to text conversions. Note that
this can be used to control the precision of float return values
for ECI commands. [-]
int-set-log-history-length
Sets the log history length. Defaults to 0 items.
This command was introduced in ecasound 2.4.0. [-]
int-cmd-version-string
Returns ecasound interactive mode parser version string. [s]
int-cmd-version-lib-current
Returns ecasound interactive mode library interface version (libtool). [i]
Returns ecasound interactive mode library interface age (libtool). [i]
OBJECT MAPS
Object maps are central repositories for commonly used object types.
By querying the maps, applications can get a list of all registered
object types and their properties.
map-cop-list
Prints a list of registered chain operators using
the format specified in section OPERATOR DESCRIPTIONS. [s]
map-preset-list
Prints a list of registered effect presets using
the format specified in section OPERATOR DESCRIPTIONS. [s]
map-ladspa-list
Prints a list of registered LADSPA plugins using
the format specified in section OPERATOR DESCRIPTIONS. [s]
map-ladspa-id-list
Prints a list of registered LADSPA plugins using
the format specified in section OPERATOR DESCRIPTIONS.
Numerical LADPSA plugin identifiers are used. [s]
map-ctrl-list
Prints a list of registered controllers using
the format specified in section OPERATOR DESCRIPTIONS. [s]
DUMP COMMANDS
The following dump commands are not meant for normal use.
Their primary purpose is to provide an easy way to get
internal state information from libecasound. All dump
commands output a single line with syntax "key value"
to the selected output stream (defaults to stdout).
dump-target 'filename'
Set target stream for dumping. [-]
dump-status
Dumps engine status - 'running', 'stopped', 'finished' or 'notready'. [-]
dump-position
Dumps the global position. Printed in seconds using a floating-point
representation. [-]
dump-length
Dumps the overall processing length. Printed in seconds using a floating-point
representation. [-]
dump-cs-status
Dumps status string for the currently selected chainsetup - 'connected',
'selected' or an empty string. [-]
dump-c-selected
Dumps the name of currently selected chain. [-]
dump-ai-selected
Dumps label of currently selected audio input. If no input is
selected, dumps an empty string. [-]
dump-ai-position
Dumps position of currently selected audio inputs. Printed in
seconds, using a floating-point representation. [-]
dump-ai-length
Dumps length of currently selected audio input. Printed in seconds,
using a floating-point representation. [-]
dump-ai-open-state
Dumps audio input state info. Either 'open' or 'closed'. [-]
dump-ao-selected
Dumps label of currently selected audio output. If no output is
selected, dumps an empty string. [-]
dump-ao-position
Dumps position of currently selected audio outputs. Printed in
seconds, using a floating-point representation. [-]
dump-ao-length
Dumps length of currently selected audio output. Printed in seconds,
using a floating-point representation. [-]
dump-ao-open-state
Dumps audio output state info. Either 'open' or 'closed'. [-]
dump-cop-value 'chainop,param'
Dumps chain operator parameter value. 'chainop' and 'param' are
operator and parameter index values (1...n). [-]
OPERATOR DESCRIPTIONS
The map-xxx-list commands return a string containing all registered
objects of the given type xxx. Each line of the output describes
one registered type. The used syntax is: