NAME

ecasound-iam - ecasound interactive mode

SYNOPSIS

DESCRIPTION

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:

cs-remove, cs-set-length, cs-set-length-samples, cs-toggle-loop, cs-set-param, cs-option, c-add, c-remove, c-rename, c-clear, ai-add, ai-remove, ai-attach, ai-forward, ai-rewind, ai-set-position, ai-set-position-samples, ao-add, ao-add-default, ao-remove, ao-attach, ao-forward, ao-rewind, ao-set-position, ao-set-position-samples.

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):

cop-set, copp-set, ctrlp-set, c-bypass, c-muting, setpos, cs-set-position, *-describe *-deselect, *-get, *-list, *-register *-select, *-selected, *-status, dump-*, int-*, jack-*, map-*

GENERAL

quit, q: 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]
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: 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. [-]
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-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]
ai-select ’aobject_name’, ao-select ’aobject_name’: 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. [-]
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-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]
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. 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]
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. 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]
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. 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]
int-cmd-version-lib-revision: Returns ecasound interactive mode library interface revision (libtool). [i]
int-cmd-version-lib-age: 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:

: ’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 ecasound/libecasound/eca-operator.h.

DEPRECATED COMMANDS

Use of following commands is deprecated. They still work in current version of Ecasound, but will be dropped in the future:

ai-wave-edit, ao-wave-edit

AUTHOR

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