Description
PipeWire will soon be replacing both JACK and PulseAudio on Linux starting with Fedora 34 which will be released in a few weeks. Arch currently has packages that make it easy to switch to PipeWire. I am unclear about Ubuntu's plans and just asked them about that.
PipeWire reimplements the JACK and PulseAudio APIs. Currently the PipeWire developer is not recommending to use the new PipeWire API if applications already work well with PipeWire via JACK or PulseAudio. I am not familiar enough with cpal to know, but there might be some benefits to using the PipeWire API instead of using PipeWire via the JACK API.
PipeWire upstream already provides Rust bindings.
I have attempted to test cpal's JACK backend with PipeWire but have not gotten it to work. The pw-uninstalled.sh script sets the LD_LIBRARY_PATH environment variable so PipeWire's reimplementation of libjack is loaded before JACK's original library. I know Rust links statically to other Rust libraries but I am unclear how Rust links to dynamic C libraries. Maybe the LD_LIBRARY_PATH trick does not work with Rust?
cpal on master is 📦 v0.13.2 via 🦀 v1.49.0
❯ cargo run --release --example beep --features jack
Finished release [optimized] target(s) in 0.03s
Running `target/release/examples/beep`
Output device: default
Default output config: SupportedStreamConfig { channels: 2, sample_rate: SampleRate(44100), buffer_size: Range { min: 170, max: 1466015503 }, sample_format: F32 }
memory allocation of 5404319552844632832 bytes failed
fish: “cargo run --release --example b…” terminated by signal SIGABRT (Abort)
cpal on master is 📦 v0.13.2 via 🦀 v1.49.0
❯ ~/sw/pipewire/pw-uninstalled.sh
Using default build directory: /home/be/sw/pipewire/build
Welcome to fish, the friendly interactive shell
Type `help` for instructions on how to use fish
cpal on master is 📦 v0.13.2 via 🦀 v1.49.0
❯ cargo run --release --example beep --features jack
Finished release [optimized] target(s) in 0.03s
Running `target/release/examples/beep`
Output device: default
Default output config: SupportedStreamConfig { channels: 2, sample_rate: SampleRate(44100), buffer_size: Range { min: 170, max: 1466015503 }, sample_format: F32 }
memory allocation of 5404319552844632832 bytes failed
fish: “cargo run --release --example b…” terminated by signal SIGABRT (Abort)
Related discussions regarding PipeWire and PortAudio:
https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/130
PortAudio/portaudio#425