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 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],
integer [i], long integer [li] and floating-point number [f]. These
definitions are used throughout this document. Commands that do not
return anything 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.
Realtime commands
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'
and 'copp-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.
GENERAL
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! [-]
GLOBAL
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. [-]
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. 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]
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). [-]
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), "-m" (mixmode), "-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".
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. [-]
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-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]
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). [-]
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)). [-]
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. [-]
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-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
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. 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]
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
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]
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-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: