JACK Host

.github/workflows/cpal.yml

@@ -73,6 +73,8 @@ jobs:
       run: sudo apt update
     - name: Install alsa
       run: sudo apt-get install libasound2-dev
+    - name: Install libjack
+      run: sudo apt-get install libjack-jackd2-dev libjack-jackd2-0
     - name: Install stable
       uses: actions-rs/toolchain@v1
       with:

Cargo.toml

@@ -11,6 +11,7 @@ keywords = ["audio", "sound"]
 [features]
 asio = ["asio-sys", "num-traits"] # Only available on Windows. See README for setup instructions.
 
+
 [dependencies]
 thiserror = "1.0.2"
 
@@ -30,6 +31,7 @@ lazy_static = "1.3"
 alsa = "0.4.1"
 nix = "0.15.0"
 libc = "0.2.65"
+jack = { version = "0.6.5", optional = true }
 
 [target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies]
 coreaudio-rs = { version = "0.9.1", default-features = false, features = ["audio_unit", "core_audio"] }

examples/beep.rs

@@ -4,7 +4,33 @@ extern crate cpal;
 use cpal::traits::{DeviceTrait, HostTrait, StreamTrait};
 
 fn main() -> Result<(), anyhow::Error> {
+    // Conditionally compile with jack if the feature is specified.
+    #[cfg(all(
+        any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"),
+        feature = "jack"
+    ))]
+    // Manually check for flags. Can be passed through cargo with -- e.g.
+    // cargo run --release --example beep --features jack -- --jack
+    let host = if std::env::args()
+        .collect::<String>()
+        .contains(&String::from("--jack"))
+    {
+        cpal::host_from_id(cpal::available_hosts()
+            .into_iter()
+            .find(|id| *id == cpal::HostId::Jack)
+            .expect(
+                "make sure --features jack is specified. only works on OSes where jack is available",
+            )).expect("jack host unavailable")
+    } else {
+        cpal::default_host()
+    };
+
+    #[cfg(any(
+        not(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd")),
+        not(feature = "jack")
+    ))]
     let host = cpal::default_host();
+
     let device = host
         .default_output_device()
         .expect("failed to find a default output device");

examples/feedback.rs

@@ -16,6 +16,31 @@ use ringbuf::RingBuffer;
 const LATENCY_MS: f32 = 150.0;
 
 fn main() -> Result<(), anyhow::Error> {
+    // Conditionally compile with jack if the feature is specified.
+    #[cfg(all(
+        any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd"),
+        feature = "jack"
+    ))]
+    // Manually check for flags. Can be passed through cargo with -- e.g.
+    // cargo run --release --example beep --features jack -- --jack
+    let host = if std::env::args()
+        .collect::<String>()
+        .contains(&String::from("--jack"))
+    {
+        cpal::host_from_id(cpal::available_hosts()
+            .into_iter()
+            .find(|id| *id == cpal::HostId::Jack)
+            .expect(
+                "make sure --features jack is specified. only works on OSes where jack is available",
+            )).expect("jack host unavailable")
+    } else {
+        cpal::default_host()
+    };
+
+    #[cfg(any(
+        not(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd")),
+        not(feature = "jack")
+    ))]
     let host = cpal::default_host();
 
     // Default devices.

src/host/jack/device.rs

@@ -0,0 +1,275 @@
+use crate::{
+    BackendSpecificError, BuildStreamError, Data, DefaultStreamConfigError, DeviceNameError,
+    InputCallbackInfo, OutputCallbackInfo, SampleFormat, SampleRate, StreamConfig, StreamError,
+    SupportedBufferSize, SupportedStreamConfig, SupportedStreamConfigRange,
+    SupportedStreamConfigsError,
+};
+use std::hash::{Hash, Hasher};
+use traits::DeviceTrait;
+
+use super::stream::Stream;
+use super::JACK_SAMPLE_FORMAT;
+
+pub type SupportedInputConfigs = std::vec::IntoIter<SupportedStreamConfigRange>;
+pub type SupportedOutputConfigs = std::vec::IntoIter<SupportedStreamConfigRange>;
+
+const DEFAULT_NUM_CHANNELS: u16 = 2;
+const DEFAULT_SUPPORTED_CHANNELS: [u16; 10] = [1, 2, 4, 6, 8, 16, 24, 32, 48, 64];
+
+/// If a device is for input or output.
+/// Until we have duplex stream support JACK clients and CPAL devices for JACK will be either input or output.
+#[derive(Clone, Debug)]
+pub enum DeviceType {
+    InputDevice,
+    OutputDevice,
+}
+#[derive(Clone, Debug)]
+pub struct Device {
+    name: String,
+    sample_rate: SampleRate,
+    buffer_size: SupportedBufferSize,
+    device_type: DeviceType,
+    start_server_automatically: bool,
+    connect_ports_automatically: bool,
+}
+
+impl Device {
+    fn new_device(
+        name: String,
+        connect_ports_automatically: bool,
+        start_server_automatically: bool,
+        device_type: DeviceType,
+    ) -> Result<Self, String> {
+        // ClientOptions are bit flags that you can set with the constants provided
+        let client_options = super::get_client_options(start_server_automatically);
+
+        // Create a dummy client to find out the sample rate of the server to be able to provide it as a possible config.
+        // This client will be dropped and a new one will be created when making the stream.
+        // This is a hack due to the fact that the Client must be moved to create the AsyncClient.
+        match super::get_client(&name, client_options) {
+            Ok(client) => Ok(Device {
+                // The name given to the client by JACK, could potentially be different from the name supplied e.g.if there is a name collision
+                name: client.name().to_string(),
+                sample_rate: SampleRate(client.sample_rate() as u32),
+                buffer_size: SupportedBufferSize::Range {
+                    min: client.buffer_size(),
+                    max: client.buffer_size(),
+                },
+                device_type,
+                start_server_automatically,
+                connect_ports_automatically,
+            }),
+            Err(e) => Err(e),
+        }
+    }
+
+    pub fn default_output_device(
+        name: &str,
+        connect_ports_automatically: bool,
+        start_server_automatically: bool,
+    ) -> Result<Self, String> {
+        let output_client_name = format!("{}_out", name);
+        Device::new_device(
+            output_client_name,
+            connect_ports_automatically,
+            start_server_automatically,
+            DeviceType::OutputDevice,
+        )
+    }
+
+    pub fn default_input_device(
+        name: &str,
+        connect_ports_automatically: bool,
+        start_server_automatically: bool,
+    ) -> Result<Self, String> {
+        let input_client_name = format!("{}_in", name);
+        Device::new_device(
+            input_client_name,
+            connect_ports_automatically,
+            start_server_automatically,
+            DeviceType::InputDevice,
+        )
+    }
+
+    pub fn default_config(&self) -> Result<SupportedStreamConfig, DefaultStreamConfigError> {
+        let channels = DEFAULT_NUM_CHANNELS;
+        let sample_rate = self.sample_rate;
+        let buffer_size = self.buffer_size.clone();
+        // The sample format for JACK audio ports is always "32 bit float mono audio" in the current implementation.
+        // Custom formats are allowed within JACK, but this is of niche interest.
+        // The format can be found programmatically by calling jack::PortSpec::port_type() on a created port.
+        let sample_format = JACK_SAMPLE_FORMAT;
+        Ok(SupportedStreamConfig {
+            channels,
+            sample_rate,
+            buffer_size,
+            sample_format,
+        })
+    }
+
+    pub fn supported_configs(&self) -> Vec<SupportedStreamConfigRange> {
+        let f = match self.default_config() {
+            Err(_) => return vec![],
+            Ok(f) => f,
+        };
+
+        let mut supported_configs = vec![];
+
+        for &channels in DEFAULT_SUPPORTED_CHANNELS.iter() {
+            supported_configs.push(SupportedStreamConfigRange {
+                channels,
+                min_sample_rate: f.sample_rate,
+                max_sample_rate: f.sample_rate,
+                buffer_size: f.buffer_size.clone(),
+                sample_format: f.sample_format.clone(),
+            });
+        }
+        supported_configs
+    }
+
+    pub fn is_input(&self) -> bool {
+        match self.device_type {
+            DeviceType::InputDevice => true,
+            _ => false,
+        }
+    }
+
+    pub fn is_output(&self) -> bool {
+        match self.device_type {
+            DeviceType::OutputDevice => true,
+            _ => false,
+        }
+    }
+}
+
+impl DeviceTrait for Device {
+    type SupportedInputConfigs = SupportedInputConfigs;
+    type SupportedOutputConfigs = SupportedOutputConfigs;
+    type Stream = Stream;
+
+    fn name(&self) -> Result<String, DeviceNameError> {
+        Ok(self.name.clone())
+    }
+
+    fn supported_input_configs(
+        &self,
+    ) -> Result<Self::SupportedInputConfigs, SupportedStreamConfigsError> {
+        Ok(self.supported_configs().into_iter())
+    }
+
+    fn supported_output_configs(
+        &self,
+    ) -> Result<Self::SupportedOutputConfigs, SupportedStreamConfigsError> {
+        Ok(self.supported_configs().into_iter())
+    }
+
+    /// Returns the default input config
+    /// The sample format for JACK audio ports is always "32 bit float mono audio" unless using a custom type.
+    /// The sample rate is set by the JACK server.
+    fn default_input_config(&self) -> Result<SupportedStreamConfig, DefaultStreamConfigError> {
+        self.default_config()
+    }
+
+    /// Returns the default output config
+    /// The sample format for JACK audio ports is always "32 bit float mono audio" unless using a custom type.
+    /// The sample rate is set by the JACK server.
+    fn default_output_config(&self) -> Result<SupportedStreamConfig, DefaultStreamConfigError> {
+        self.default_config()
+    }
+
+    fn build_input_stream_raw<D, E>(
+        &self,
+        conf: &StreamConfig,
+        sample_format: SampleFormat,
+        data_callback: D,
+        error_callback: E,
+    ) -> Result<Self::Stream, BuildStreamError>
+    where
+        D: FnMut(&Data, &InputCallbackInfo) + Send + 'static,
+        E: FnMut(StreamError) + Send + 'static,
+    {
+        if let DeviceType::OutputDevice = &self.device_type {
+            // Trying to create an input stream from an output device
+            return Err(BuildStreamError::StreamConfigNotSupported);
+        }
+        if conf.sample_rate != self.sample_rate || sample_format != JACK_SAMPLE_FORMAT {
+            return Err(BuildStreamError::StreamConfigNotSupported);
+        }
+        // The settings should be fine, create a Client
+        let client_options = super::get_client_options(self.start_server_automatically);
+        let client;
+        match super::get_client(&self.name, client_options) {
+            Ok(c) => client = c,
+            Err(e) => {
+                return Err(BuildStreamError::BackendSpecific {
+                    err: BackendSpecificError {
+                        description: e.to_string(),
+                    },
+                })
+            }
+        };
+        let mut stream = Stream::new_input(client, conf.channels, data_callback, error_callback);
+
+        if self.connect_ports_automatically {
+            stream.connect_to_system_inputs();
+        }
+
+        Ok(stream)
+    }
+
+    fn build_output_stream_raw<D, E>(
+        &self,
+        conf: &StreamConfig,
+        sample_format: SampleFormat,
+        data_callback: D,
+        error_callback: E,
+    ) -> Result<Self::Stream, BuildStreamError>
+    where
+        D: FnMut(&mut Data, &OutputCallbackInfo) + Send + 'static,
+        E: FnMut(StreamError) + Send + 'static,
+    {
+        if let DeviceType::InputDevice = &self.device_type {
+            // Trying to create an output stream from an input device
+            return Err(BuildStreamError::StreamConfigNotSupported);
+        }
+        if conf.sample_rate != self.sample_rate || sample_format != JACK_SAMPLE_FORMAT {
+            return Err(BuildStreamError::StreamConfigNotSupported);
+        }
+
+        // The settings should be fine, create a Client
+        let client_options = super::get_client_options(self.start_server_automatically);
+        let client;
+        match super::get_client(&self.name, client_options) {
+            Ok(c) => client = c,
+            Err(e) => {
+                return Err(BuildStreamError::BackendSpecific {
+                    err: BackendSpecificError {
+                        description: e.to_string(),
+                    },
+                })
+            }
+        };
+        let mut stream = Stream::new_output(client, conf.channels, data_callback, error_callback);
+
+        if self.connect_ports_automatically {
+            stream.connect_to_system_outputs();
+        }
+
+        Ok(stream)
+    }
+}
+
+impl PartialEq for Device {
+    fn eq(&self, other: &Self) -> bool {
+        // Device::name() can never fail in this implementation
+        self.name().unwrap() == other.name().unwrap()
+    }
+}
+
+impl Eq for Device {}
+
+impl Hash for Device {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.name().unwrap().hash(state);
+    }
+}