PipeWire Module: Example Filter

The example filter is a good starting point for writing a custom filter.

We refer to the source code for more information.

Module Options

• node.description: a human readable name for the filter streams
• capture.props = {}: properties to be passed to the input stream
• playback.props = {}: properties to be passed to the output stream

General options

Options with well-known behavior. Most options can be added to the global configuration or the individual streams:

• PW_KEY_REMOTE_NAME
• PW_KEY_AUDIO_RATE
• PW_KEY_AUDIO_CHANNELS
• SPA_KEY_AUDIO_POSITION
• PW_KEY_MEDIA_NAME
• PW_KEY_NODE_LATENCY
• PW_KEY_NODE_DESCRIPTION
• PW_KEY_NODE_GROUP
• PW_KEY_NODE_LINK_GROUP
• PW_KEY_NODE_VIRTUAL
• PW_KEY_NODE_NAME: See notes below. If not specified, defaults to 'filter-<pid>-<module-id>'.

Stream only properties:

• PW_KEY_MEDIA_CLASS
• PW_KEY_NODE_NAME: if not given per stream, the global node.name will be prefixed with 'input.' and 'output.' to generate a capture and playback stream node.name respectively.

Example configuration of a virtual source

context.modules = [
{   name = libpipewire-module-example-filter
    args = {
      node.description = "Example Filter"
      capture.props = {
          audio.position = [ FL FR ]
          node.passive = true
      }
      playback.props = {
          node.name = "Example Filter"
          media.class = "Audio/Source"
          audio.position = [ FL FR ]
      }
    }
}
]

pw-cli -m lm libpipewire-module-example-filter '{ audio.position=[FL FR] }'