libpipewire-module-metadata - Man Page

Allows clients to export a metadata store to the PipeWire server.

Both the client and the server need to load this module for the metadata to be exported.

This module creates a new factory and a new export type for the PW_TYPE_INTERFACE_Metadata interface.

A client will first create an implementation of the PW_TYPE_INTERFACE_Metadata interface with pw_context_create_metadata(), for example. With the pw_core_export(), this module will create a server side resource to expose the metadata implementation to other clients. Modifications done by the client on the local metadata interface will be visible to all PipeWire clients.

It is also possible to use the factory to create metadata in the current processes using a config file fragment.

As an argument to the create_object call, a set of properties will control the name of the metadata and some initial values.

libpipewire-module-metadata

This module has no options.

• metadata.name: The name of the new metadata object. If not given, the metadata object name will be default.
• metadata.values: A JSON array of objects with initial values for the metadata object.

the metadata.values key has the following layout:

metadata.values = [
   { id = <int>  key = <key>  type = <type> value = <object> }
   ....
]

 ·

id: an optional object id for the metadata, default 0

 ·

key: a string, the metadata key

 ·

type: an optional metadata value type

 ·

value: a JSON item, the metadata value.

The module is usually added to the config file of the main PipeWire daemon and the clients.

context.modules = [
{ name = libpipewire-module-metadata }
]

To create an object from the factory, one can use the pw_core_create_object() method or make an object in the context.objects section like in the main PipeWire daemon config file:

context.objects = [
{ factory = metadata
    args = {
        metadata.name = default
        metadata.values = [
           { key = default.audio.sink   value = { name = somesink } }
           { key = default.audio.source value = { name = somesource } }
        ]
    }
}

This creates a new default metadata store with 2 key/values.

• pw-metadata: a tool to manage metadata

libpipewire-modules(7).