Add Rodio audio pipeline as alternative to current LiveKit pipeline (#36607)

Rodio parts are well tested and need less configuration then the livekit
parts. I suspect there is a bug in the livekit configuration regarding
resampling. Rather then investigate that it seemed faster & easier to
swap in Rodio.

This opens the door to using other Rodio parts like:
 - Decibel based volume control
 - Limiter (prevents sound from becoming too loud)
 - Automatic gain control

To use this add to settings:
```
  "audio": {
    "experimental.rodio_audio": true
  }
```

Release Notes:

- N/A

Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Antonio Scandurra <me@as-cii.com>

crates/audio/Cargo.toml

@@ -15,9 +15,10 @@ doctest = false
 [dependencies]
 anyhow.workspace = true
 collections.workspace = true
-derive_more.workspace = true
 gpui.workspace = true
-parking_lot.workspace = true
+settings.workspace = true
+schemars.workspace = true
+serde.workspace = true
 rodio = { workspace = true, features = [ "wav", "playback", "tracing" ] }
 util.workspace = true
 workspace-hack.workspace = true

crates/audio/src/assets.rs

@@ -1,54 +0,0 @@
-use std::{io::Cursor, sync::Arc};
-
-use anyhow::{Context as _, Result};
-use collections::HashMap;
-use gpui::{App, AssetSource, Global};
-use rodio::{Decoder, Source, source::Buffered};
-
-type Sound = Buffered<Decoder<Cursor<Vec<u8>>>>;
-
-pub struct SoundRegistry {
-    cache: Arc<parking_lot::Mutex<HashMap<String, Sound>>>,
-    assets: Box<dyn AssetSource>,
-}
-
-struct GlobalSoundRegistry(Arc<SoundRegistry>);
-
-impl Global for GlobalSoundRegistry {}
-
-impl SoundRegistry {
-    pub fn new(source: impl AssetSource) -> Arc<Self> {
-        Arc::new(Self {
-            cache: Default::default(),
-            assets: Box::new(source),
-        })
-    }
-
-    pub fn global(cx: &App) -> Arc<Self> {
-        cx.global::<GlobalSoundRegistry>().0.clone()
-    }
-
-    pub(crate) fn set_global(source: impl AssetSource, cx: &mut App) {
-        cx.set_global(GlobalSoundRegistry(SoundRegistry::new(source)));
-    }
-
-    pub fn get(&self, name: &str) -> Result<impl Source<Item = f32> + use<>> {
-        if let Some(wav) = self.cache.lock().get(name) {
-            return Ok(wav.clone());
-        }
-
-        let path = format!("sounds/{}.wav", name);
-        let bytes = self
-            .assets
-            .load(&path)?
-            .map(anyhow::Ok)
-            .with_context(|| format!("No asset available for path {path}"))??
-            .into_owned();
-        let cursor = Cursor::new(bytes);
-        let source = Decoder::new(cursor)?.buffered();
-
-        self.cache.lock().insert(name.to_string(), source.clone());
-
-        Ok(source)
-    }
-}

crates/audio/src/audio.rs

@@ -1,16 +1,19 @@
-use assets::SoundRegistry;
-use derive_more::{Deref, DerefMut};
-use gpui::{App, AssetSource, BorrowAppContext, Global};
-use rodio::{OutputStream, OutputStreamBuilder};
+use anyhow::{Context as _, Result, anyhow};
+use collections::HashMap;
+use gpui::{App, BorrowAppContext, Global};
+use rodio::{Decoder, OutputStream, OutputStreamBuilder, Source, source::Buffered};
+use settings::Settings;
+use std::io::Cursor;
 use util::ResultExt;
 
-mod assets;
+mod audio_settings;
+pub use audio_settings::AudioSettings;
 
-pub fn init(source: impl AssetSource, cx: &mut App) {
-    SoundRegistry::set_global(source, cx);
-    cx.set_global(GlobalAudio(Audio::new()));
+pub fn init(cx: &mut App) {
+    AudioSettings::register(cx);
 }
 
+#[derive(Copy, Clone, Eq, Hash, PartialEq)]
 pub enum Sound {
     Joined,
     Leave,
@@ -38,18 +41,12 @@ impl Sound {
 #[derive(Default)]
 pub struct Audio {
     output_handle: Option<OutputStream>,
+    source_cache: HashMap<Sound, Buffered<Decoder<Cursor<Vec<u8>>>>>,
 }
 
-#[derive(Deref, DerefMut)]
-struct GlobalAudio(Audio);
-
-impl Global for GlobalAudio {}
+impl Global for Audio {}
 
 impl Audio {
-    pub fn new() -> Self {
-        Self::default()
-    }
-
     fn ensure_output_exists(&mut self) -> Option<&OutputStream> {
         if self.output_handle.is_none() {
             self.output_handle = OutputStreamBuilder::open_default_stream().log_err();
@@ -58,26 +55,51 @@ impl Audio {
         self.output_handle.as_ref()
     }
 
-    pub fn play_sound(sound: Sound, cx: &mut App) {
-        if !cx.has_global::<GlobalAudio>() {
-            return;
-        }
+    pub fn play_source(
+        source: impl rodio::Source + Send + 'static,
+        cx: &mut App,
+    ) -> anyhow::Result<()> {
+        cx.update_default_global(|this: &mut Self, _cx| {
+            let output_handle = this
+                .ensure_output_exists()
+                .ok_or_else(|| anyhow!("Could not open audio output"))?;
+            output_handle.mixer().add(source);
+            Ok(())
+        })
+    }
 
-        cx.update_global::<GlobalAudio, _>(|this, cx| {
+    pub fn play_sound(sound: Sound, cx: &mut App) {
+        cx.update_default_global(|this: &mut Self, cx| {
+            let source = this.sound_source(sound, cx).log_err()?;
             let output_handle = this.ensure_output_exists()?;
-            let source = SoundRegistry::global(cx).get(sound.file()).log_err()?;
             output_handle.mixer().add(source);
             Some(())
         });
     }
 
     pub fn end_call(cx: &mut App) {
-        if !cx.has_global::<GlobalAudio>() {
-            return;
-        }
-
-        cx.update_global::<GlobalAudio, _>(|this, _| {
+        cx.update_default_global(|this: &mut Self, _cx| {
             this.output_handle.take();
         });
     }
+
+    fn sound_source(&mut self, sound: Sound, cx: &App) -> Result<impl Source + use<>> {
+        if let Some(wav) = self.source_cache.get(&sound) {
+            return Ok(wav.clone());
+        }
+
+        let path = format!("sounds/{}.wav", sound.file());
+        let bytes = cx
+            .asset_source()
+            .load(&path)?
+            .map(anyhow::Ok)
+            .with_context(|| format!("No asset available for path {path}"))??
+            .into_owned();
+        let cursor = Cursor::new(bytes);
+        let source = Decoder::new(cursor)?.buffered();
+
+        self.source_cache.insert(sound, source.clone());
+
+        Ok(source)
+    }
 }

crates/audio/src/audio_settings.rs

@@ -0,0 +1,33 @@
+use anyhow::Result;
+use gpui::App;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use settings::{Settings, SettingsSources};
+
+#[derive(Deserialize, Debug)]
+pub struct AudioSettings {
+    /// Opt into the new audio system.
+    #[serde(rename = "experimental.rodio_audio", default)]
+    pub rodio_audio: bool, // default is false
+}
+
+/// Configuration of audio in Zed.
+#[derive(Clone, Default, Serialize, Deserialize, JsonSchema, Debug)]
+#[serde(default)]
+pub struct AudioSettingsContent {
+    /// Whether to use the experimental audio system
+    #[serde(rename = "experimental.rodio_audio", default)]
+    pub rodio_audio: bool,
+}
+
+impl Settings for AudioSettings {
+    const KEY: Option<&'static str> = Some("audio");
+
+    type FileContent = AudioSettingsContent;
+
+    fn load(sources: SettingsSources<Self::FileContent>, _cx: &mut App) -> Result<Self> {
+        sources.json_merge()
+    }
+
+    fn import_from_vscode(_vscode: &settings::VsCodeSettings, _current: &mut Self::FileContent) {}
+}