ecasound-iam - ecasound interactive mode

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.

A special case of EIAM use is ecasound's control interface (ECI), which is a small library providing easy access to the EIAM commands from outside of libecasound. When issuing EIAM commands using ECI, 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 EIAM results in an error, a error string explaining the condition is returned.

It's not possible to use all EIAM commands to modify and control objects that belong to a connected chainsetup. Commands that do support this are: 'start', 'stop', 'setpos', 'rewind', 'forward', 'c-select', 'c-muting', 'c-bypass', 'cop-select', 'copp-select', 'copp-value', 'ctrlp-select' and 'ctrlp-value'.

Another set of commands are those which can be used with connected chainsetups, but not without an audible break. These are: 'cop-add', 'cop-remove', 'ctrl-add', 'ctrl-select', 'ctrl-remove'

In addition, most non-modifying (const) commands work with connected setups.

quit, q

Quit ecasound session. What this means in practice depends on the client (library throws an exception). [-]

start, t

Processing is started (play). [-]

stop, s

Stop processing. [-]

run

Like 'start' but blocks until processing is finished. [-]

debug 'debug-level'

Set debug level to 'debug-level'. Notice that client programs can reimplement the debug routines. [-]

help', 'h'

Help! [-]

engine-status

Returns a string describing the engine status (running, stopped, finished, error, not ready). See also cs-status. [s]

engine-launch

Initializes and starts the engine. Doesn't start the actual processing. See also start. [-]

engine-halt

Stops the engine. Does not disconnect the chainsetup that was running. See also stop. [-]

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. Only one chainsetup can be connected at a time. [-]

cs-disconnect

Disconnect currently connected chainsetup. [-]

cs-connected

Returns the name of currently connected chainsetup. [s]

cs-rewind 'time-in-seconds', rewind 'time-in-seconds', rw 'time-in-seconds'

Rewinds the current chainsetup position by 'time-in-seconds' seconds. Position of all inputs and outputs attached to the selected chainsetup is also affected. [-]

cs-forward 'time-in-seconds', forward 'time-in-seconds', fw 'ttime-in-seconds'

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. [-]

cs-set-position 'time-in-seconds', cs-setpos 'time-in-seconds', setpos 'time-in-seconds', set-position 'time-in-seconds'

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

Print status info about all chainsetups. [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! EIAM implicitly interprets all strings beginning with a '-' as "cs-option string".

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. [-]

c-index-select 'index1,...,indexN', c-iselect 'index1,...,indexN'

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-muting

Toggle chain muting. When chain is muted, all data that goes through is muted. [-]

c-mute

Toggle chain muting. Note! Deprecated, use c-muting instead. [-]

c-bypass

Toggle chain bypassing. When chain is bypassed, sample data is passed through untouched. [-]

c-status, cs

Print status info about all chains. [s]

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). [-]

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)). [-]

ao-add-default

Adds the default output device (see ecasoundrc(5)). [-]

ai-select 'aobject_name', ao-select 'aobject_name'

Selects an audio object. 'aobject_name' refers to the string used when creating the object (see above). Note! All input object names are required to be unique. Similarly all output names need to be unique. However, it's possible that the same object name exists both as an input and as an output. [-]

ai-index-select 'aobject_index', ai-iselect 'aobject_index', ao-index-select 'aobject_index', ao-iselect 'aobject_index'

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. [-]

ai-forward 'time_in_seconds', ai-fw 'time_in_seconds', ao-forward 'time_in_seconds', ao-fw 'time_in_seconds'

Selected audio object is forwarded by 'time-in-seconds' seconds. Time should be given as a floating point value (eg. 0.001 is the same as 1ms). [-]

ai-rewind 'time_in_seconds', ai-rw 'time_in_seconds', ao-rewind 'time_in_seconds', ao-rw 'time_in_seconds'

Selected audio object is rewinded by 'time-in-seconds' seconds. Time should be given as a floating point value (eg. 0.001 is the same as 1ms). [-]

ai-setpos 'time_in_seconds', ai-set-position 'time_in_seconds', ao-setpos 'time_in_seconds', ao-set-position 'time_in_seconds'

Set audio object position to 'time_in_seconds'. [-]

ai-set-position-samples 'time_in_samples', ao-set-position-samples 'time_in_samples'

Set audio object position to 'time_in_samples'. [-]

ai-getpos, ai-get-position, ao-getpos, ao-get-position

Returns the audio object position in seconds. [f]

ai-get-position-samples, ao-get-position-samples

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-wave-edit, ao-wave-edit

The currently selected audio object is loaded into an external wave editor (see ecasoundrc(5)). [-]

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 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. Argument format is "-<id_string>:par1,...,parN". 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-remove

Removes the selected chain operator. [-]

cop-list

Returns a list of all chain operators attached to the currently selected chain. [S]

cop-select 'param_id', cop-index-select 'param_id', cop-iselect 'param_id'

Selects a chain operator. [-]

cop-selected

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. [-]

cop-status

Returns info about chain operator status. [s]

copp-list

Returns a list of selected chain operator's parameters. [S]

copp-select 'param_id', copp-index-select 'param_id', copp-iselect 'param_id'

Selects a chain operator parameter. [-]

copp-selected

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. [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 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. Argument format is "-<id_string>:<param_id>,<range_low>, <range_high>,par1,...,parN". See ecasound(1) man page for more info. [-]

ctrl-remove

Removes the selected controller. [-]

ctrl-list

Returns a list of all controllers attached to the currently selected chain. [S]

ctrl-select 'param_id', ctrl-index-select 'param_id', ctrl-iselect 'param_id'

Selects a controller. [-]

ctrl-selected

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. [S]

ctrlp-select

Selects a controller parameter. [-]

ctrlp-selected

Returns the index number of currently selected controller parameter. [i]

ctrlp-get

Returns the selected controller parameter value. [f]

ctrlp-set

Sets the selected controller parameter value to 'value'. [-]

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 EIAM 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. [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 5 items. [-]

int-cmd-version-string

Returns EIAM parser version string. [s]

int-cmd-version-lib-current

Returns EIAM library interface version (libtool). [i]

int-cmd-version-lib-revision

Returns EIAM library interface revision (libtool). [i]

int-cmd-version-lib-age

Returns EIAM library interface age (libtool). [i]

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]

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). [-]

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:

'keyword,name,description,num_of_params,par1_def,par2_def,...'

parX_def describes one object parameter. This definition is present for all parameters of the described object type. The used syntax is:

'name,description,defaultvalue,upper_bound_flag,upper_bound, lower_bound_flag,lower_bound,toggled_flag,integer_flag, logarithmic_flag,output_flag'

For exact descriptions of these fields, please see the header file emph(ecasound/libecasound/eca-operator.h).

ecasound(1), ecatools (1), ecasoundrc(5)

Kai Vehmanen, <kvehmanen -at- eca -dot- cx>