Bluez 5 Bluetooth Audio ALSA Backend.
Bluez-ALSA (BlueALSA) is an ALSA backend for Bluez 5 audio interface. Bluez-ALSA registers all Bluetooth devices with audio profiles in Bluez under a virtual ALSA PCM device called bluealsa that supports both playback and capture.
Some backstory: Bluez 5 removed built-in support for ALSA in favor of a generic interface for 3rd party appliations. Thereafter, PulseAudio implemented a backend for that interface and became the only way to get Bluetooth audio with Bluez 5. Users prefering ALSA stayed on Bluez 4. However, Bluez 4 eventually became deprecated.
This package is a rebirth of a direct interface between ALSA and Bluez 5, that, unlike PulseAudio, provides KISS near-metal-like experience. It is not possible to run BluezALSA and PulseAudio Bluetooth at the same time due to limitations in Bluez, but it is possible to run PulseAudio over BluezALSA if you disable bluetooth-discover and bluez5-discover modules in PA and configure it to play/capture sound over bluealsa PCM.