Support AudioRenderer protocol for AudioManager

Sources/LiveKit/Protocols/AudioCustomProcessingDelegate.swift

@@ -40,9 +40,16 @@ public protocol AudioCustomProcessingDelegate {
 }
 
 class AudioCustomProcessingDelegateAdapter: NSObject, LKRTCAudioCustomProcessingDelegate {
-    //
+    // MARK: - Public
+
     public var target: AudioCustomProcessingDelegate? { _state.target }
 
+    // MARK: - Internal
+
+    let audioRenderers = MulticastDelegate<AudioRenderer>(label: "AudioRenderer")
+
+    // MARK: - Private
+
     private struct State {
         weak var target: AudioCustomProcessingDelegate?
     }
@@ -62,7 +69,13 @@ class AudioCustomProcessingDelegateAdapter: NSObject, LKRTCAudioCustomProcessing
     }
 
     func audioProcessingProcess(audioBuffer: LKRTCAudioBuffer) {
-        target?.audioProcessingProcess(audioBuffer: LKAudioBuffer(audioBuffer: audioBuffer))
+        let lkAudioBuffer = LKAudioBuffer(audioBuffer: audioBuffer)
+        target?.audioProcessingProcess(audioBuffer: lkAudioBuffer)
+
+        // Convert to pcmBuffer and notify only if an audioRenderer is added.
+        if audioRenderers.isDelegatesNotEmpty, let pcmBuffer = lkAudioBuffer.toAVAudioPCMBuffer() {
+            audioRenderers.notify { $0.render?(pcmBuffer: pcmBuffer) }
+        }
     }
 
     func audioProcessingRelease() {

Sources/LiveKit/Protocols/AudioRenderer.swift

@@ -14,6 +14,7 @@
  * limitations under the License.
  */
 
+import AVFoundation
 import CoreMedia
 
 #if swift(>=5.9)
@@ -25,7 +26,11 @@ internal import LiveKitWebRTC
 @objc
 public protocol AudioRenderer {
     /// CMSampleBuffer for this track.
+    @objc optional
     func render(sampleBuffer: CMSampleBuffer)
+
+    @objc optional
+    func render(pcmBuffer: AVAudioPCMBuffer)
 }
 
 class AudioRendererAdapter: NSObject, LKRTCAudioRenderer {
@@ -36,7 +41,7 @@ class AudioRendererAdapter: NSObject, LKRTCAudioRenderer {
     }
 
     func render(sampleBuffer: CMSampleBuffer) {
-        target?.render(sampleBuffer: sampleBuffer)
+        target?.render?(sampleBuffer: sampleBuffer)
     }
 
     // Proxy the equality operators

Sources/LiveKit/Track/AudioManager.swift

@@ -313,3 +313,30 @@ public class AudioManager: Loggable {
     }
     #endif
 }
+
+public extension AudioManager {
+    /// Add an ``AudioRenderer`` to receive pcm buffers from local input (mic).
+    /// Only ``AudioRenderer/render(pcmBuffer:)`` will be called.
+    /// Usage: `AudioManager.shared.add(localAudioRenderer: localRenderer)`
+    func add(localAudioRenderer delegate: AudioRenderer) {
+        capturePostProcessingDelegateAdapter.audioRenderers.add(delegate: delegate)
+    }
+
+    func remove(localAudioRenderer delegate: AudioRenderer) {
+        capturePostProcessingDelegateAdapter.audioRenderers.remove(delegate: delegate)
+    }
+}
+
+public extension AudioManager {
+    /// Add an ``AudioRenderer`` to receive pcm buffers from combined remote audio.
+    /// Only ``AudioRenderer/render(pcmBuffer:)`` will be called.
+    /// To receive buffer for individual tracks, use ``RemoteAudioTrack/add(audioRenderer:)`` instead.
+    /// Usage: `AudioManager.shared.add(remoteAudioRenderer: localRenderer)`
+    func add(remoteAudioRenderer delegate: AudioRenderer) {
+        renderPreProcessingDelegateAdapter.audioRenderers.add(delegate: delegate)
+    }
+
+    func remove(remoteAudioRenderer delegate: AudioRenderer) {
+        renderPreProcessingDelegateAdapter.audioRenderers.remove(delegate: delegate)
+    }
+}

Sources/LiveKit/Track/Remote/RemoteAudioTrack.swift

@@ -95,7 +95,7 @@ public class RemoteAudioTrack: Track, RemoteTrack, AudioTrack {
 extension RemoteAudioTrack: AudioRenderer {
     public func render(sampleBuffer: CMSampleBuffer) {
         _rendererState.audioRenderers.notify { audioRenderer in
-            audioRenderer.render(sampleBuffer: sampleBuffer)
+            audioRenderer.render?(sampleBuffer: sampleBuffer)
         }
     }
 }