PipeWire: Context

PipeWire 0.3.46

Files | Data Structures | Macros | Functions
Context
Core API

The PipeWire context object manages all locally available resources. More...

## Files
file | context.h
| `pipewire/context.h`

## Data Structures
struct | pw_context_events
| context events emitted by the context object added with pw_context_add_listener More...
struct | pw_export_type
| data for registering export functions More...
struct | pw_context
struct | pw_global
struct | pw_impl_client

## Macros
#define | PW_VERSION_CONTEXT_EVENTS 0

## Functions
struct pw_context * | pw_context_new (struct pw_loop *main_loop, struct pw_properties *props, size_t user_data_size)
| Make a new context object for a given main_loop. More...
void | pw_context_destroy (struct pw_context *context)
| destroy a context object, all resources except the main_loop will be destroyed More...
void * | pw_context_get_user_data (struct pw_context *context)
| Get the context user data. More...
void | pw_context_add_listener (struct pw_context *context, struct spa_hook *listener, const struct pw_context_events *events, void *data)
| Add a new event listener to a context. More...
const struct pw_properties * | pw_context_get_properties (struct pw_context *context)
| Get the context properties. More...
int | pw_context_update_properties (struct pw_context *context, const struct spa_dict *dict)
| Update the context properties. More...
const char * | pw_context_get_conf_section (struct pw_context *context, const char *section)
| Get a config section for this context. More...
int | pw_context_parse_conf_section (struct pw_context *context, struct pw_properties *conf, const char *section)
| Parse a standard config section for this context. More...
int | pw_context_conf_update_props (struct pw_context *context, const char *section, struct pw_properties *props)
| update properties from a section into props. More...
int | pw_context_conf_section_for_each (struct pw_context *context, const char *section, int(*callback)(void *data, const char *location, const char *section, const char *str, size_t len), void *data)
| emit callback for all config sections. More...
int | pw_context_conf_section_match_rules (struct pw_context *context, const char *section, struct spa_dict *props, int(*callback)(void *data, const char *location, const char *action, const char *str, size_t len), void *data)
| emit callback for all matched properties. More...
const struct spa_support * | pw_context_get_support (struct pw_context *context, uint32_t *n_support)
| Get the context support objects. More...
struct pw_loop * | pw_context_get_main_loop (struct pw_context *context)
| get the context main loop More...
struct pw_work_queue * | pw_context_get_work_queue (struct pw_context *context)
| Get the work queue from the context: Since 0.3.26. More...
int | pw_context_for_each_global (struct pw_context *context, int(*callback)(void *data, struct pw_global *global), void *data)
| Iterate the globals of the context. More...
struct pw_global * | pw_context_find_global (struct pw_context *context, uint32_t id)
| Find a context global by id. More...
int | pw_context_add_spa_lib (struct pw_context *context, const char *factory_regex, const char *lib)
| add a spa library for the given factory_name regex More...
const char * | pw_context_find_spa_lib (struct pw_context *context, const char *factory_name)
| find the library name for a spa factory More...
struct spa_handle * | pw_context_load_spa_handle (struct pw_context *context, const char *factory_name, const struct spa_dict *info)
int | pw_context_register_export_type (struct pw_context *context, struct pw_export_type *type)
| register a type that can be exported on a context_proxy. More...
const struct pw_export_type * | pw_context_find_export_type (struct pw_context *context, const char *type)
| find information about registered export type More...
int | pw_context_set_object (struct pw_context *context, const char *type, void *value)
| add an object to the context More...
void * | pw_context_get_object (struct pw_context *context, const char *type)
| get an object from the context More...

## Detailed Description

The PipeWire context object manages all locally available resources.

It is used by both clients and servers.

The context is used to:

- Load modules and extend the functionality. This includes extending the protocol with new object types or creating any of the available objects.
- Create implementations of various objects like nodes, devices, factories, modules, etc.. This will usually also create pw_global objects that can then be shared with clients.
- Connect to another PipeWire instance (the main daemon, for example) and interact with it (See page_core_api).
- Export a local implementation of an object to another instance.

## Macro Definition Documentation

## ◆ PW_VERSION_CONTEXT_EVENTS

#define PW_VERSION_CONTEXT_EVENTS 0

## Function Documentation

## ◆ pw_context_new()

struct pw_context * pw_context_new | ( | struct pw_loop * | main_loop,
|  | struct pw_properties * | properties,
|  | size_t | user_data_size
| ) |  |

Make a new context object for a given main_loop.

Ownership of the properties is taken

Make a new context object for a given main_loop.

Parameters

  main_loop | the main loop to use
  properties | extra properties for the context, ownership it taken

Returns
  a newly allocated context object

Parameters

  main_loop | a main loop to run in
  properties | extra properties
  user_data_size | extra user data size

Examples
  bluez-session.c, export-sink.c, export-source.c, export-spa-device.c, export-spa.c, local-v4l2.c, tutorial2.c, tutorial3.c, tutorial6.c, and video-src.c.

## ◆ pw_context_destroy()

void pw_context_destroy | ( | struct pw_context * | context | ) |

destroy a context object, all resources except the main_loop will be destroyed

destroy a context object, all resources except the main_loop will be destroyed

Parameters

  context | a context to destroy

Examples
  bluez-session.c, export-sink.c, export-source.c, export-spa-device.c, export-spa.c, local-v4l2.c, tutorial2.c, tutorial3.c, tutorial6.c, and video-src.c.

## ◆ pw_context_get_user_data()

void * pw_context_get_user_data | ( | struct pw_context * | context | ) |

Get the context user data.

## ◆ pw_context_add_listener()

void pw_context_add_listener | ( | struct pw_context * | context,
|  | struct spa_hook * | listener,
|  | const struct pw_context_events * | events,
|  | void * | data
| ) |  |

Add a new event listener to a context.

## ◆ pw_context_get_properties()

const struct pw_properties * pw_context_get_properties | ( | struct pw_context * | context | ) |

Get the context properties.

## ◆ pw_context_update_properties()

int pw_context_update_properties | ( | struct pw_context * | context,
|  | const struct spa_dict * | dict
| ) |  |

Update the context properties.

Update the context properties.

Parameters

  context | a context
  dict | properties to update

Update the context object with the given properties

## ◆ pw_context_get_conf_section()

const char * pw_context_get_conf_section | ( | struct pw_context * | context,
|  | const char * | section
| ) |  |

Get a config section for this context.

Since 0.3.22, deprecated, use pw_context_conf_section_for_each().

## ◆ pw_context_parse_conf_section()

int pw_context_parse_conf_section | ( | struct pw_context * | context,
|  | struct pw_properties * | conf,
|  | const char * | section
| ) |  |

Parse a standard config section for this context.

Since 0.3.22

## ◆ pw_context_conf_update_props()

int pw_context_conf_update_props | ( | struct pw_context * | context,
|  | const char * | section,
|  | struct pw_properties * | props
| ) |  |

update properties from a section into props.

Since 0.3.45

## ◆ pw_context_conf_section_for_each()

int pw_context_conf_section_for_each | ( | struct pw_context * | context,
|  | const char * | section,
|  | int(*)(void *data, const char *location, const char *section, const char *str, size_t len) | callback,
|  | void * | data
| ) |  |

emit callback for all config sections.

Since 0.3.45

## ◆ pw_context_conf_section_match_rules()

int pw_context_conf_section_match_rules | ( | struct pw_context * | context,
|  | const char * | section,
|  | struct spa_dict * | props,
|  | int(*)(void *data, const char *location, const char *action, const char *str, size_t len) | callback,
|  | void * | data
| ) |  |

emit callback for all matched properties.

Since 0.3.46

## ◆ pw_context_get_support()

const struct spa_support * pw_context_get_support | ( | struct pw_context * | context,
|  | uint32_t * | n_support
| ) |  |

Get the context support objects.

## ◆ pw_context_get_main_loop()

struct pw_loop * pw_context_get_main_loop | ( | struct pw_context * | context | ) |

get the context main loop

## ◆ pw_context_get_work_queue()

struct pw_work_queue * pw_context_get_work_queue | ( | struct pw_context * | context | ) |

Get the work queue from the context: Since 0.3.26.

## ◆ pw_context_for_each_global()

int pw_context_for_each_global | ( | struct pw_context * | context,
|  | int(*)(void *data, struct pw_global *global) | callback,
|  | void * | data
| ) |  |

Iterate the globals of the context.

The callback should return 0 to fetch the next item, any other value stops the iteration and returns the value. When all callbacks return 0, this function returns 0 when all globals are iterated.

## ◆ pw_context_find_global()

struct pw_global * pw_context_find_global | ( | struct pw_context * | context,
|  | uint32_t | id
| ) |  |

Find a context global by id.

Parameters

  context | the context
  id | the global id

## ◆ pw_context_add_spa_lib()

int pw_context_add_spa_lib | ( | struct pw_context * | context,
|  | const char * | factory_regex,
|  | const char * | lib
| ) |  |

add a spa library for the given factory_name regex

## ◆ pw_context_find_spa_lib()

const char * pw_context_find_spa_lib | ( | struct pw_context * | context,
|  | const char * | factory_name
| ) |  |

find the library name for a spa factory

## ◆ pw_context_load_spa_handle()

struct spa_handle * pw_context_load_spa_handle | ( | struct pw_context * | context,
|  | const char * | factory_name,
|  | const struct spa_dict * | info
| ) |  |

Examples
  bluez-session.c, and export-spa.c.

## ◆ pw_context_register_export_type()

int pw_context_register_export_type | ( | struct pw_context * | context,
|  | struct pw_export_type * | type
| ) |  |

register a type that can be exported on a context_proxy.

This is usually used by extension modules

## ◆ pw_context_find_export_type()

const struct pw_export_type * pw_context_find_export_type | ( | struct pw_context * | context,
|  | const char * | type
| ) |  |

find information about registered export type

## ◆ pw_context_set_object()

int pw_context_set_object | ( | struct pw_context * | context,
|  | const char * | type,
|  | void * | value
| ) |  |

add an object to the context

## ◆ pw_context_get_object()

void * pw_context_get_object | ( | struct pw_context * | context,
|  | const char * | type
| ) |  |

get an object from the context