Use the librespot name arg for the app name in the PulseAudio backend

This sets the name displayed by PulseAudio to Librespot - Instance Name if a name is given otherwise Librespot (the default name).

This also sets the correct "role" as per the docs:

https://www.freedesktop.org/wiki/Software/PulseAudio/Documentation/Developer/Clients/ApplicationProperties/

PA_PROP_MEDIA_ROLE

"This is a property of the actual streamed data, not so much the application"

Roles are used for policies, things like automatically muting a music player when a call comes in and whatnot.

For bonus points this also sets PULSE_PROP_application.icon_name to audio-x-generic so that we get a nice icon in the PulseAudio settings by our name instead of a missing icon placeholder.

Author: JasonLG1979

CHANGELOG.md

@@ -23,6 +23,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - [main] Add a `-q`, `--quiet` option that changes the logging level to warn.
 - [main] Add a short name for every flag and option.
 - [main] Add the ability to parse environment variables.
+- [playback] `pulseaudio`: set the PulseAudio name to match librespot's device name via `PULSE_PROP_application.name` environment variable (user set env var value takes precedence). (breaking)
+- [playback] `pulseaudio`: set icon to `audio-x-generic` so we get an icon instead of a placeholder via `PULSE_PROP_application.icon_name` environment variable (user set env var value takes precedence). (breaking)
+- [playback] `pulseaudio`: set values to: `PULSE_PROP_application.version`, `PULSE_PROP_application.process.binary`, `PULSE_PROP_stream.description`, `PULSE_PROP_media.software` and `PULSE_PROP_media.role` environment variables (user set env var values take precedence). (breaking)
 
 ### Fixed
 - [main] Prevent hang when discovery is disabled and there are no credentials or when bad credentials are given.

playback/src/audio_backend/pulseaudio.rs

@@ -5,11 +5,9 @@ use crate::decoder::AudioPacket;
 use crate::{NUM_CHANNELS, SAMPLE_RATE};
 use libpulse_binding::{self as pulse, error::PAErr, stream::Direction};
 use libpulse_simple_binding::Simple;
+use std::env;
 use thiserror::Error;
 
-const APP_NAME: &str = "librespot";
-const STREAM_NAME: &str = "Spotify endpoint";
-
 #[derive(Debug, Error)]
 enum PulseError {
     #[error("<PulseAudioSink> Unsupported Pulseaudio Sample Spec, Format {pulse_format:?} ({format:?}), Channels {channels}, Rate {rate}")]
@@ -47,13 +45,18 @@ impl From<PulseError> for SinkError {
 }
 
 pub struct PulseAudioSink {
-    s: Option<Simple>,
+    sink: Option<Simple>,
     device: Option<String>,
+    app_name: String,
+    stream_desc: String,
     format: AudioFormat,
 }
 
 impl Open for PulseAudioSink {
     fn open(device: Option<String>, format: AudioFormat) -> Self {
+        let app_name = env::var("PULSE_PROP_application.name").unwrap_or_default();
+        let stream_desc = env::var("PULSE_PROP_stream.description").unwrap_or_default();
+
         let mut actual_format = format;
 
         if actual_format == AudioFormat::F64 {
@@ -64,16 +67,18 @@ impl Open for PulseAudioSink {
         info!("Using PulseAudioSink with format: {:?}", actual_format);
 
         Self {
-            s: None,
+            sink: None,
             device,
+            app_name,
+            stream_desc,
             format: actual_format,
         }
     }
 }
 
 impl Sink for PulseAudioSink {
     fn start(&mut self) -> SinkResult<()> {
-        if self.s.is_none() {
+        if self.sink.is_none() {
             // PulseAudio calls S24 and S24_3 different from the rest of the world
             let pulse_format = match self.format {
                 AudioFormat::F32 => pulse::sample::Format::FLOAT32NE,
@@ -84,13 +89,13 @@ impl Sink for PulseAudioSink {
                 _ => unreachable!(),
             };
 
-            let ss = pulse::sample::Spec {
+            let sample_spec = pulse::sample::Spec {
                 format: pulse_format,
                 channels: NUM_CHANNELS,
                 rate: SAMPLE_RATE,
             };
 
-            if !ss.is_valid() {
+            if !sample_spec.is_valid() {
                 let pulse_error = PulseError::InvalidSampleSpec {
                     pulse_format,
                     format: self.format,
@@ -101,30 +106,28 @@ impl Sink for PulseAudioSink {
                 return Err(SinkError::from(pulse_error));
             }
 
-            let s = Simple::new(
+            let sink = Simple::new(
                 None,                   // Use the default server.
-                APP_NAME,               // Our application's name.
+                &self.app_name,         // Our application's name.
                 Direction::Playback,    // Direction.
                 self.device.as_deref(), // Our device (sink) name.
-                STREAM_NAME,            // Description of our stream.
-                &ss,                    // Our sample format.
+                &self.stream_desc,      // Description of our stream.
+                &sample_spec,           // Our sample format.
                 None,                   // Use default channel map.
                 None,                   // Use default buffering attributes.
             )
             .map_err(PulseError::ConnectionRefused)?;
 
-            self.s = Some(s);
+            self.sink = Some(sink);
         }
 
         Ok(())
     }
 
     fn stop(&mut self) -> SinkResult<()> {
-        let s = self.s.as_mut().ok_or(PulseError::NotConnected)?;
-
-        s.drain().map_err(PulseError::DrainFailure)?;
+        let sink = self.sink.take().ok_or(PulseError::NotConnected)?;
 
-        self.s = None;
+        sink.drain().map_err(PulseError::DrainFailure)?;
         Ok(())
     }
 
@@ -133,9 +136,9 @@ impl Sink for PulseAudioSink {
 
 impl SinkAsBytes for PulseAudioSink {
     fn write_bytes(&mut self, data: &[u8]) -> SinkResult<()> {
-        let s = self.s.as_mut().ok_or(PulseError::NotConnected)?;
+        let sink = self.sink.as_mut().ok_or(PulseError::NotConnected)?;
 
-        s.write(data).map_err(PulseError::OnWrite)?;
+        sink.write(data).map_err(PulseError::OnWrite)?;
 
         Ok(())
     }

src/main.rs

@@ -1124,6 +1124,43 @@ fn get_setup() -> Setup {
             exit(1);
         }
 
+        #[cfg(feature = "pulseaudio-backend")]
+        {
+            if env::var("PULSE_PROP_application.name").is_err() {
+                let pulseaudio_name = if name != connect_default_config.name {
+                    format!("{} - {}", connect_default_config.name, name)
+                } else {
+                    name.clone()
+                };
+
+                env::set_var("PULSE_PROP_application.name", pulseaudio_name);
+            }
+
+            if env::var("PULSE_PROP_application.version").is_err() {
+                env::set_var("PULSE_PROP_application.version", version::SEMVER);
+            }
+
+            if env::var("PULSE_PROP_application.icon_name").is_err() {
+                env::set_var("PULSE_PROP_application.icon_name", "audio-x-generic");
+            }
+
+            if env::var("PULSE_PROP_application.process.binary").is_err() {
+                env::set_var("PULSE_PROP_application.process.binary", "librespot");
+            }
+
+            if env::var("PULSE_PROP_stream.description").is_err() {
+                env::set_var("PULSE_PROP_stream.description", "Spotify Connect endpoint");
+            }
+
+            if env::var("PULSE_PROP_media.software").is_err() {
+                env::set_var("PULSE_PROP_media.software", "Spotify");
+            }
+
+            if env::var("PULSE_PROP_media.role").is_err() {
+                env::set_var("PULSE_PROP_media.role", "music");
+            }
+        }
+
         let initial_volume = opt_str(INITIAL_VOLUME)
             .map(|initial_volume| {
                 let volume = match initial_volume.parse::<u16>() {