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