BtMachine

BtMachine — base class for signal processing machines

Functions

Properties

GstElement * adder-convert Read
gpointer construction-error Read / Write / Construct Only
gulong global-params Read
gchar * id Read / Write / Construct
GstElement * input-gain Read
GstElement * input-post-level Read
GstElement * input-pre-level Read
GstElement * machine Read
GstElement * output-gain Read
GstElement * output-post-level Read
GstElement * output-pre-level Read
gpointer patterns Read
gchar * plugin-name Read / Write / Construct
gulong prefs-params Read
gchar * pretty-name Read
gpointer properties Read
BtSong * song Read / Write / Construct Only
BtMachineState state Read / Write
gulong voice-params Read
gulong voices Read / Write / Construct

Signals

void pattern-added No Hooks
void pattern-removed No Hooks

Types and Values

Object Hierarchy

    GEnum
    ╰── BtMachineState
    GObject
    ╰── GInitiallyUnowned
        ╰── GstObject
            ╰── GstElement
                ╰── GstBin
                    ╰── BtMachine
                        ├── BtProcessorMachine
                        ├── BtSinkMachine
                        ╰── BtSourceMachine

Implemented Interfaces

BtMachine implements GstChildProxy and BtPersistence.

Includes

#include <libbtcore/core.h>

Description

Machines are pieces in a BtSong that generate, process or play media.

The machine class takes care of inserting additional low-level elemnts to do signal conversion etc.. Further it provides general facillities like input/output level monitoring. The resulting machine instance is a box containing several processing elements.

A machine can have several GstElements:

adder:

mixes all incoming signals

input volume:

gain for incoming signals

input pre/post-gain level:

level meter for incoming signal

machine:

the real machine

output volume:

gain for outgoing signal

output pre/post-gain level:

level meter for outgoing signal

spreader:

distibutes signal to outgoing connections

The adder and spreader elements are activated depending on element type. The volume controls and level meters are activated as requested via the API. It is recommended to only activate them, when needed. The instances are cached after deactivation (so that they can be easily reactivated) and destroyed with the BtMachine object.

Furthermore the machine handles a list of BtCmdPattern instances. These contain event patterns that form a BtSequence.

Functions

bt_machine_activate_adder ()

gboolean
bt_machine_activate_adder (BtMachine * const self);

Machines use an adder to allow multiple incoming wires. This method is used by the BtWire class to activate the adder when needed.

Parameters

self

the machine to activate the adder in

 

Returns

TRUE for success


bt_machine_activate_spreader ()

gboolean
bt_machine_activate_spreader (BtMachine * const self);

Machines use a spreader to allow multiple outgoing wires. This method is used by the BtWire class to activate the spreader when needed.

Parameters

self

the machine to activate the spreader in

 

Returns

TRUE for success


bt_machine_add_pattern ()

void
bt_machine_add_pattern (const BtMachine *self,
                        const BtCmdPattern *pattern);

Add the supplied pattern to the machine. This is automatically done by bt_pattern_new().

Parameters

self

the machine to add the pattern to

 

pattern

the new pattern instance

 

bt_machine_bind_parameter_control ()

void
bt_machine_bind_parameter_control (const BtMachine * const self,
                                   GstObject *object,
                                   const gchar *property_name,
                                   BtIcControl *control,
                                   BtParameterGroup *pg);

Connect the interaction control object to the give parameter. Changes of the control-value are mapped into a change of the parameter.

Parameters

self

machine

 

object

child object (global or voice child)

 

property_name

name of the parameter

 

control

interaction control object

 

pg

the parameter group of the property

 

bt_machine_bind_poly_parameter_control ()

void
bt_machine_bind_poly_parameter_control
                               (const BtMachine * const self,
                                const gchar *property_name,
                                BtIcControl *control,
                                BtParameterGroup *pg);

Connect the interaction control object to the give parameter. Changes of the control-value are mapped into a change of the parameter.

Parameters

self

machine

 

property_name

name of the parameter

 

control

interaction control object

 

pg

the parameter group of the property

 

bt_machine_enable_input_gain ()

gboolean
bt_machine_enable_input_gain (BtMachine * const self);

Creates the input-gain element of the machine and activates it.

Parameters

self

the machine to enable the input-gain element in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_enable_input_post_level ()

gboolean
bt_machine_enable_input_post_level (BtMachine * const self);

Creates the post-gain input-level analyser of the machine and activates it.

Parameters

self

the machine to enable the post-gain input-level analyser in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_enable_input_pre_level ()

gboolean
bt_machine_enable_input_pre_level (BtMachine * const self);

Creates the pre-gain input-level analyser of the machine and activates it.

Parameters

self

the machine to enable the pre-gain input-level analyser in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_enable_output_gain ()

gboolean
bt_machine_enable_output_gain (BtMachine * const self);

Creates the output-gain element of the machine and activates it.

Parameters

self

the machine to enable the output-gain element in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_enable_output_post_level ()

gboolean
bt_machine_enable_output_post_level (BtMachine * const self);

Creates the post-gain output-level analyser of the machine and activates it.

Parameters

self

the machine to enable the post-gain output-level analyser in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_enable_output_pre_level ()

gboolean
bt_machine_enable_output_pre_level (BtMachine * const self);

Creates the pre-gain output-level analyser of the machine and activates it.

Parameters

self

the machine to enable the pre-gain output-level analyser in

 

Returns

TRUE for success, FALSE otherwise


bt_machine_get_global_param_group ()

BtParameterGroup *
bt_machine_get_global_param_group (const BtMachine * const self);

Get the parameter group of global parameters.

Parameters

self

the machine

 

Returns

the BtParameterGroup or NULL.

[transfer none]


bt_machine_get_pattern_by_index ()

BtCmdPattern *
bt_machine_get_pattern_by_index (const BtMachine * const self,
                                 const gulong index);

Fetches the pattern from the given position of the machines pattern list. The pattern must have been added previously to this setup with bt_machine_add_pattern().

Parameters

self

the machine to search for the pattern

 

index

the index of the pattern in the machines pattern list

 

Returns

BtCmdPattern instance or NULL if not found. Unref the pattern, when done with it.

[transfer full]


bt_machine_get_pattern_by_name ()

BtCmdPattern *
bt_machine_get_pattern_by_name (const BtMachine * const self,
                                const gchar * const name);

Search the machine for a pattern by the supplied name. The pattern must have been added previously to this setup with bt_machine_add_pattern().

Parameters

self

the machine to search for the pattern

 

name

the name of the pattern

 

Returns

BtCmdPattern instance or NULL if not found. Unref the pattern, when done with it.

[transfer full]


bt_machine_get_prefs_param_group ()

BtParameterGroup *
bt_machine_get_prefs_param_group (const BtMachine * const self);

Get the parameter group of machine properties. Properties are settings that cannot be changed during playback.

Parameters

self

the machine

 

Returns

the BtParameterGroup or NULL.

[transfer none]


bt_machine_get_unique_pattern_name ()

gchar *
bt_machine_get_unique_pattern_name (const BtMachine * const self);

The function generates a unique pattern name for this machine by eventually adding a number postfix. This method should be used when adding new patterns.

Parameters

self

the machine for which the name should be unique

 

Returns

the newly allocated unique name.

[transfer full]


bt_machine_get_voice_param_group ()

BtParameterGroup *
bt_machine_get_voice_param_group (const BtMachine * const self,
                                  const gulong voice);

Get the parameter group of voice parameters for the given voice .

Parameters

self

the machine

 

voice

the voice number

 

Returns

the BtParameterGroup or NULL.

[transfer none]


bt_machine_get_wire_by_dst_machine ()

BtWire *
bt_machine_get_wire_by_dst_machine (const BtMachine * const self,
                                    const BtMachine * const dst);

Searches for a wire in the wires originating from this machine that uses the given BtMachine instances as a target.

Parameters

self

the machine that is at src of a wire

 

dst

the machine that is at the dst end of the wire

 

Returns

the BtWire or NULL. Unref the wire, when done with it.

[transfer full]

Since: 0.6


bt_machine_handles_waves ()

gboolean
bt_machine_handles_waves (const BtMachine * const self);

Tells if the machine is using the wave-table.

Parameters

self

the machine to check

 

Returns

TRUE for wavetable machines, FALSE otherwise

Since: 0.7


bt_machine_has_active_adder ()

gboolean
bt_machine_has_active_adder (const BtMachine * const self);

Checks if the machine currently uses an adder. This method is used by the BtWire class to activate the adder when needed.

Parameters

self

the machine to check

 

Returns

TRUE for success


bt_machine_has_active_spreader ()

gboolean
bt_machine_has_active_spreader (const BtMachine * const self);

Checks if the machine currently uses an spreader. This method is used by the BtWire class to activate the spreader when needed.

Parameters

self

the machine to check

 

Returns

TRUE for success


bt_machine_has_patterns ()

gboolean
bt_machine_has_patterns (const BtMachine * const self);

Check if the machine has BtPattern entries appart from the standart private ones.

Parameters

self

the machine for which to check the patterns

 

Returns

TRUE if it has patterns


bt_machine_is_polyphonic ()

gboolean
bt_machine_is_polyphonic (const BtMachine * const self);

Tells if the machine can produce (multiple) voices. Monophonic machines have their (one) voice params as part of the global params.

Parameters

self

the machine to check

 

Returns

TRUE for polyphic machines, FALSE for monophonic ones


bt_machine_randomize_parameters ()

void
bt_machine_randomize_parameters (const BtMachine * const self);

Randomizes machine parameters.

Parameters

self

machine

 

bt_machine_remove_pattern ()

void
bt_machine_remove_pattern (const BtMachine *self,
                           const BtCmdPattern *pattern);

Remove the given pattern from the machine.

Parameters

self

the machine to remove the pattern from

 

pattern

the existing pattern instance

 

bt_machine_reset_parameters ()

void
bt_machine_reset_parameters (const BtMachine * const self);

Resets machine parameters back to defaults.

Parameters

self

machine

 

bt_machine_set_param_defaults ()

void
bt_machine_set_param_defaults (const BtMachine *const self);

Sets default values that should be used before the first control-point. Should be called, if all parameters are changed (like after switching presets).

Parameters

self

the machine

 

bt_machine_unbind_parameter_control ()

void
bt_machine_unbind_parameter_control (const BtMachine * const self,
                                     GstObject *object,
                                     const gchar *property_name);

Disconnect the interaction control object from the give parameter.

Parameters

self

machine

 

object

child object (global or voice child)

 

property_name

name of the parameter

 

bt_machine_unbind_parameter_controls ()

void
bt_machine_unbind_parameter_controls (const BtMachine * const self);

Disconnect all interaction controls.

Parameters

self

machine

 

Types and Values

struct BtMachine

struct BtMachine {
  /*< read-only >*/
  GList *src_wires;
  GList *dst_wires;
};

Base object for a virtual piece of hardware (generator, effect, ...).

Members

GList *src_wires;

read-only list of outgoing BtWire objects

 

GList *dst_wires;

read-only list of incomming BtWire objects

 

struct BtMachineClass

struct BtMachineClass {
  /* virtual methods for subclasses */
  gboolean (*check_type)(const BtMachine * const machine, const gulong pad_src_ct, const gulong pad_sink_ct);
};

Base class for machines.

Members

check_type ()

sanity check that the given input/output characteristics are okay for the implementation

 

enum BtMachineState

A machine is always in one of the 4 states. Use the "state" property of the BtMachine to change or query the current state.

Members

BT_MACHINE_STATE_NORMAL

just working

 

BT_MACHINE_STATE_MUTE

be quiet

 

BT_MACHINE_STATE_SOLO

be the only one playing

 

BT_MACHINE_STATE_BYPASS

be uneffective (pass through)

 

Property Details

The “adder-convert” property

  “adder-convert”            GstElement *

the after mixing format converter element, if any.

Flags: Read


The “construction-error” property

  “construction-error”       gpointer

signal failed instance creation.

Flags: Read / Write / Construct Only


The “global-params” property

  “global-params”            gulong

number of dynamic params for the machine.

Flags: Read


The “id” property

  “id”                       gchar *

machine identifier.

Flags: Read / Write / Construct

Default value: "unamed machine"


The “input-gain” property

  “input-gain”               GstElement *

the input-gain element, if any.

Flags: Read


The “input-post-level” property

  “input-post-level”         GstElement *

the post-gain input-level element, if any.

Flags: Read


The “input-pre-level” property

  “input-pre-level”          GstElement *

the pre-gain input-level element, if any.

Flags: Read


The “machine” property

  “machine”                  GstElement *

the machine element, if any.

Flags: Read


The “output-gain” property

  “output-gain”              GstElement *

the output-gain element, if any.

Flags: Read


The “output-post-level” property

  “output-post-level”        GstElement *

the post-gain output-level element, if any.

Flags: Read


The “output-pre-level” property

  “output-pre-level”         GstElement *

the pre-gain output-level element, if any.

Flags: Read


The “patterns” property

  “patterns”                 gpointer

a copy of the list of patterns.

Flags: Read


The “plugin-name” property

  “plugin-name”              gchar *

the name of the gst plugin for the machine.

Flags: Read / Write / Construct

Default value: "unamed plugin"


The “prefs-params” property

  “prefs-params”             gulong

number of static params for the machine.

Flags: Read


The “pretty-name” property

  “pretty-name”              gchar *

pretty-printed name for display purposes.

Flags: Read

Default value: NULL


The “properties” property

  “properties”               gpointer

hashtable of machine properties.

Flags: Read


The “song” property

  “song”                     BtSong *

song object, the machine belongs to.

Flags: Read / Write / Construct Only


The “state” property

  “state”                    BtMachineState

the current state of this machine.

Flags: Read / Write

Default value: BT_MACHINE_STATE_NORMAL


The “voice-params” property

  “voice-params”             gulong

number of dynamic params for each machine voice.

Flags: Read


The “voices” property

  “voices”                   gulong

number of voices in the machine.

Flags: Read / Write / Construct

Signal Details

The “pattern-added” signal

void
user_function (BtMachine *self,
               BtPattern *pattern,
               gpointer   user_data)

A new pattern item has been added to the machine

Parameters

self

the machine object that emitted the signal

 

pattern

the new pattern

 

user_data

user data set when the signal handler was connected.

 

Flags: No Hooks


The “pattern-removed” signal

void
user_function (BtMachine *self,
               BtPattern *pattern,
               gpointer   user_data)

A pattern item has been removed from the machine

Parameters

self

the machine object that emitted the signal

 

pattern

the old pattern

 

user_data

user data set when the signal handler was connected.

 

Flags: No Hooks