Pipewire device enumeration includes non-device objects

[mbernat]

Bug Description

#72 revealed that all kinds of objects are included when listing devices (physical devices, sinks, sources, bridges, streams). It would be preferable to only list the sinks and sources.

Steps To Reproduce

Run the enumerate_pipewire example

• either on main and check the object media.class with wpctl or a similar tool; or
• on feature: pipewire device props #72, which also displays the object properties, no external tools needed.

Expected Behavior

Only sources and sinks are listed.

Actual Behavior

Many other kinds of objects are listed.

Environment

• OS: linux
• Audio driver (enable info logs): pipewire
• Rust Version: 1.87.0
• Project Version/Commit (see Cargo.lock): 8ec6c84f42efd0b556e78302a5ec2c5a385e2d60

Additional Context

N/A

Possible Solution

Filter the listed objects, probably using media.class.

[mccadecortez]

Would DeviceType's bitflags work?

interflow/src/backends/pipewire/utils.rs

Lines 10 to 26 in 8ec6c84

	fn get_device_type(object: &GlobalObject<&DictRef>) -> Option<DeviceType> {
	fn is_input(media_class: &str) -> bool {
	let str = media_class.trim().to_lowercase();
	str == "audio/source"
	}
	fn is_output(str: &str) -> bool {
	let str = str.trim().to_lowercase();
	str == "audio/sink"
	}
	let media_class = object.props?.get("media.class")?;
	let mut device_type = DeviceType::empty();
	device_type.set(DeviceType::INPUT, is_input(media_class));
	device_type.set(DeviceType::OUTPUT, is_output(media_class));
	Some(device_type)
	}

fn get_device_type(object: &GlobalObject<&DictRef>) -> Option<DeviceType> {
    let media_class = object.props?.get("media.class")?;
    let mut device_type = DeviceType::empty();

    log::debug!("media_class: {}", media_class.trim().to_lowercase());
    match (media_class.trim().to_lowercase()).as_str() {
        "audio/source" => device_type.set(DeviceType::INPUT, true),
        "audio/sink" => device_type.set(DeviceType::OUTPUT, true),
        "audio/device" => device_type.set(DeviceType::PHYSICAL, true),
        "stream/output/audio" => device_type.set(DeviceType::APPLICATION, true),
        _ => return None,
    }

    Some(device_type)
}

[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "48", "factory.id": "15", "client.id": "47", "device.api": "alsa", "device.description": "TU104 HD Audio Controller", "device.name": "alsa_card.pci-0000_0d_00.1", "device.nick": "HDA NVidia", "media.class": "Audio/Device"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_card.pci-0000_0d_00.1 (DeviceType(PHYSICAL))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "49", "factory.id": "15", "client.id": "47", "device.api": "alsa", "device.description": "Rembrandt Radeon High Definition Audio Controller", "device.name": "alsa_card.pci-0000_11_00.1", "device.nick": "HD-Audio Generic", "media.class": "Audio/Device"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_card.pci-0000_11_00.1 (DeviceType(PHYSICAL))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "50", "factory.id": "15", "client.id": "47", "device.api": "alsa", "device.description": "Family 17h/19h/1ah HD Audio Controller", "device.name": "alsa_card.pci-0000_11_00.6", "device.nick": "HD-Audio Generic", "media.class": "Audio/Device"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_card.pci-0000_11_00.6 (DeviceType(PHYSICAL))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "1461", "object.path": "alsa:acp:Generic:0:playback", "factory.id": "19", "client.id": "47", "device.id": "49", "priority.session": "1196", "priority.driver": "1196", "node.description": "Rembrandt Radeon High Definition Audio Controller Pro", "node.name": "alsa_output.pci-0000_11_00.1.pro-output-3", "node.nick": "65S421", "media.class": "Audio/Sink"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_output.pci-0000_11_00.1.pro-output-3 (DeviceType(OUTPUT))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "1462", "object.path": "alsa:acp:Generic:1:playback", "factory.id": "19", "client.id": "47", "device.id": "49", "priority.session": "1132", "priority.driver": "1132", "node.description": "Rembrandt Radeon High Definition Audio Controller Pro 7", "node.name": "alsa_output.pci-0000_11_00.1.pro-output-7", "node.nick": "HDMI 1", "media.class": "Audio/Sink"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_output.pci-0000_11_00.1.pro-output-7 (DeviceType(OUTPUT))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "1463", "object.path": "alsa:acp:Generic:2:playback", "factory.id": "19", "client.id": "47", "device.id": "49", "priority.session": "1116", "priority.driver": "1116", "node.description": "Rembrandt Radeon High Definition Audio Controller Pro 8", "node.name": "alsa_output.pci-0000_11_00.1.pro-output-8", "node.nick": "HDMI 2", "media.class": "Audio/Sink"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_output.pci-0000_11_00.1.pro-output-8 (DeviceType(OUTPUT))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "1464", "object.path": "alsa:acp:Generic:3:playback", "factory.id": "19", "client.id": "47", "device.id": "49", "priority.session": "1100", "priority.driver": "1100", "node.description": "Rembrandt Radeon High Definition Audio Controller Pro 9", "node.name": "alsa_output.pci-0000_11_00.1.pro-output-9", "node.nick": "HDMI 3", "media.class": "Audio/Sink"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        alsa_output.pci-0000_11_00.1.pro-output-9 (DeviceType(OUTPUT))
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] global.props: DictRef { flags: Flags(0x0), entries: {"object.serial": "2918", "factory.id": "7", "client.id": "175", "client.api": "pipewire-pulse", "application.name": "Chromium", "node.name": "Chromium", "media.class": "Stream/Output/Audio"} }
[2025-07-09T16:47:27Z DEBUG interflow::backends::pipewire::device] [Core/Done] id: 0 seq: 3
        Chromium (DeviceType(APPLICATION))

Reference: https://github.com/dimtpap/obs-pipewire-audio-capture/blob/5920784e00a1af0848a722fa112cb5fee9c9e6bb/src/pipewire-audio-capture-app.c#L739

[SolarLiner]

The revised method looks good; I would set the PHYSICAL flag on audio/source and audio/sink since they look like the media class is only used for non-application outputs (not sure how to differentiate physical from virtual outputs). Similarly for the application outputs, they would benefit from additionally marking them as OUTPUT (and is there an equivalent class for application inputs?)