add basic airpods max 2 support (linux only)

[sachin3796]

Airpods Max 2 support

[sachin3796]

Great project by the way!

Tested the basic application.

Screenshot of Airpods Max 2 in use:

Log from command line tool (censored MAC addresses and the Cloud Keys):

sach@arch-desktop ~/D/P/l/l/build (feature/airpods-max-2-support)> ./librepods
qt.bluetooth.bluez: Missing CAP_NET_ADMIN permission. Cannot determine whether a found address is of random or public type.
librepods:  Initializing LibrePods
librepods:  PulseAudio controller initialized
librepods:  Set ear detection behavior to:  MediaController::PauseWhenBothRemoved
librepods:  Connecting to device:  "Sach’s AirPods Max"
librepods:  AirPodsTrayApp initialized
librepods:  Noise control mode is already set to:  2
qt.qpa.services: Failed to register with host portal QDBusError("org.freedesktop.portal.Error.Failed", "Could not register app ID: App info not found for 'me.kavishdevar.librepods'")
librepods:  Connected to device, sending initial packets
qrc:/linux/PodColumn.qml:24:5: QML QQuickImage: Cannot open: qrc:/icons/assets/max_case.png
librepods:  Parsed AirPods metadata:
librepods:  Device Name:  "Sach’s AirPods Max"
librepods:  Model Number:  "A3454"
librepods:  Manufacturer:  "Apple Inc."
librepods:  Device output name set to:  "bluez_card.XX_XX_XX_XX_XX_XX"
librepods:  Noise control mode is already set to:  1
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Conversational awareness state received:  false
librepods:  One Bud ANC mode received:  false
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Primary Pod: Battery::Component::Headset
librepods:  Battery status:  "Headset: 31%"
librepods:  At least one AirPod is in ear
librepods:  Selected best available A2DP profile:  "a2dp-sink-sbc_xq"
librepods:  Activating A2DP profile for AirPods:  "a2dp-sink-sbc_xq"
librepods:  A2DP profile activated successfully
librepods:  Received Magic Cloud Keys:
librepods:  MagicAccIRK:  "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
librepods:  MagicAccEncKey:  "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
librepods:  Device output name set to:  "bluez_card.XX_XX_XX_XX_XX_XX"
librepods:  Selected best available A2DP profile:  "a2dp-sink-sbc_xq"
librepods:  Activating A2DP profile for AirPods:  "a2dp-sink-sbc_xq"
librepods:  A2DP profile activated successfully
librepods:  A2DP profile activation attempted for newly connected device
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Adaptive
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Adaptive
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Off
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Off
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Adaptive
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Adaptive
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Transparency
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::NoiseCancellation
librepods:  Setting noise control mode to:  AirpodsTrayApp::Enums::NoiseControlMode::Off
librepods:  Noise control mode received:  AirpodsTrayApp::Enums::NoiseControlMode::Off

Can confirm that the modes are operating as expected.

I am not able to confirm the BLE modelId is correct at the moment, but I'm pretty sure I extracted it correctly by forcing the headphones in to BLE mode via bluetoothctl and dumping the bluetooth header with btmon.

[sachin3796]

have now confirmed that the BLE modelId is now correct, and have updated the documentation with the correct value (0x2D20)

[sachin3796]

As a note to add, I've had issues with the default selected codec "SBC-XQ" - if this codec is used, audio from the computer only comes out of the left speaker channel. This is likely a hardware limitation.

I've worked around this by adding the following to my wireplumber configuration:

$ cat .config/wireplumber/wireplumber.conf.d/12-disable-sbc-xq-profile.conf
monitor.bluez.properties = {
    bluez5.enable-sbc-xq = false
}

Both the bluetooth default SBC codec and AAC work correctly.