Add docstrings explaining the role of capture/render processing delegates more clearly

Sources/LiveKit/Protocols/AudioCustomProcessingDelegate.swift

@@ -24,17 +24,24 @@ internal import LiveKitWebRTC
 
 public let kLiveKitKrispAudioProcessorName = "livekit_krisp_noise_cancellation"
 
+/// Used to modify audio buffers before they are sent to the network or played to the user
 @objc
 public protocol AudioCustomProcessingDelegate {
+    /// An optional identifier for the audio processor implementation.
+    /// This can be used to identify different types of audio processing (e.g. noise cancellation).
+    /// Generally you can leave this as the default value.
     @objc optional
     var audioProcessingName: String { get }
 
+    /// Provides the sample rate and number of channels to configure your delegate for processing
     @objc
     func audioProcessingInitialize(sampleRate sampleRateHz: Int, channels: Int)
 
+    /// Provides a chunk of audio data that can be modified in place
     @objc
     func audioProcessingProcess(audioBuffer: LKAudioBuffer)
 
+    /// Called when the audio processing is no longer needed so it may clean up any resources
     @objc
     func audioProcessingRelease()
 }

Sources/LiveKit/Protocols/AudioRenderer.swift

@@ -23,6 +23,8 @@ internal import LiveKitWebRTC
 @_implementationOnly import LiveKitWebRTC
 #endif
 
+/// Used to observe audio buffers before playback, e.g. for visualization, recording, etc
+/// - Note: AudioRenderer is not suitable for buffer modification. If you need to modify the buffer, use `AudioCustomProcessingDelegate` instead.
 @objc
 public protocol AudioRenderer {
     @objc
@@ -38,7 +40,6 @@ class AudioRendererAdapter: MulticastDelegate<AudioRenderer>, LKRTCAudioRenderer
     }
 
     // MARK: - LKRTCAudioRenderer
-
     func render(pcmBuffer: AVAudioPCMBuffer) {
         notify { $0.render(pcmBuffer: pcmBuffer) }
     }

Sources/LiveKit/Track/AudioManager.swift

@@ -169,6 +169,9 @@ public class AudioManager: Loggable {
 
     let capturePostProcessingDelegateSubject = CurrentValueSubject<AudioCustomProcessingDelegate?, Never>(nil)
 
+    /// Add a delegate to modify the local audio buffer before it is sent to the network
+    /// - Note: Only one delegate can be set at a time, but you can create one to wrap others if needed
+    /// - Note: If you only need to observe the buffer (rather than modify it), use ``add(localAudioRenderer:)`` instead
     public var capturePostProcessingDelegate: AudioCustomProcessingDelegate? {
         get { capturePostProcessingDelegateAdapter.target }
         set {
@@ -177,6 +180,10 @@ public class AudioManager: Loggable {
         }
     }
 
+    /// Add a delegate to modify the combined remote audio buffer (all tracks) before it is played to the user
+    /// - Note: Only one delegate can be set at a time, but you can create one to wrap others if needed
+    /// - Note: If you only need to observe the buffer (rather than modify it), use ``add(remoteAudioRenderer:)`` instead
+    /// - Note: If you need to observe the buffer for individual tracks, use ``RemoteAudioTrack/add(audioRenderer:)`` instead
     public var renderPreProcessingDelegate: AudioCustomProcessingDelegate? {
         get { renderPreProcessingDelegateAdapter.target }
         set { renderPreProcessingDelegateAdapter.set(target: newValue) }