clearer commentS

Author: stephen-derosa

include/livekit/subscription_thread_dispatcher.h

@@ -67,13 +67,15 @@ using DataFrameCallbackId = std::uint64_t;
 ///
 /// `SubscriptionThreadDispatcher` is the low-level companion to @ref Room's
 /// remote track subscription flow. `Room` forwards user-facing callback
-/// registration requests here, and then calls @ref handleTrackSubscribed and
-/// @ref handleTrackUnsubscribed as room events arrive.
+/// registration requests here. For remote audio and video subscriptions it
+/// calls @ref handleTrackSubscribed and @ref handleTrackUnsubscribed; for
+/// data tracks it calls @ref handleDataTrackPublished and
+/// @ref handleDataTrackUnpublished.
 ///
-/// For each registered `(participant identity, track name)` pair, this class
-/// may create a dedicated @ref AudioStream or @ref VideoStream and a matching
-/// reader thread. That thread blocks on stream reads and invokes the
-/// registered callback with decoded frames.
+/// For each registered audio or video `(participant identity, track name)`
+/// pair, this class may create a dedicated @ref AudioStream or @ref
+/// VideoStream and a matching reader thread. That thread blocks on stream
+/// reads and invokes the registered callback with decoded frames.
 ///
 /// This type is intentionally independent from @ref RoomDelegate. High-level
 /// room events such as `RoomDelegate::onTrackSubscribed()` remain in @ref Room,
@@ -153,27 +155,33 @@ class LIVEKIT_API SubscriptionThreadDispatcher {
   /// @param track_name           Track name to clear.
   void clearOnVideoFrameCallback(const std::string& participant_identity, const std::string& track_name);
 
-  /// Start or restart reader dispatch for a newly subscribed remote track.
+  /// Start or restart reader dispatch for a newly subscribed remote audio or
+  /// video track.
   ///
   /// @ref Room calls this after it has processed a track-subscription event and
-  /// updated its publication state. If a matching callback registration exists,
-  /// the dispatcher creates the appropriate stream type and launches a reader
-  /// thread for the `(participant, track_name)` key.
+  /// updated its publication state. If a matching audio or video callback
+  /// registration exists, the dispatcher creates the appropriate @ref
+  /// AudioStream or @ref VideoStream and launches a reader thread for the
+  /// `(participant, track_name)` key.
   ///
-  /// If no matching callback is registered, this is a no-op.
+  /// Remote data tracks are handled separately via @ref handleDataTrackPublished.
+  /// If @p track is not audio or video, or no matching callback is registered,
+  /// this is a no-op.
   ///
   /// @param participant_identity Identity of the remote participant.
   /// @param track_name           Track name associated with the subscription.
-  /// @param track                Subscribed remote track to read from.
+  /// @param track                Subscribed remote audio or video track to read from.
   void handleTrackSubscribed(const std::string& participant_identity, const std::string& track_name,
                              const std::shared_ptr<Track>& track);
 
-  /// Stop reader dispatch for an unsubscribed remote track.
+  /// Stop reader dispatch for an unsubscribed remote audio or video track.
   ///
-  /// @ref Room calls this when a remote track is unsubscribed. Any active
-  /// reader stream for the given `(participant, track_name)` key is closed and its
-  /// thread is joined. Callback registration is preserved so future
-  /// re-subscription can start dispatch again automatically.
+  /// @ref Room calls this when a remote audio or video track is unsubscribed.
+  /// Any active reader stream for the given `(participant, track_name)` key is
+  /// closed and its thread is joined. Callback registration is preserved so
+  /// future re-subscription can start dispatch again automatically.
+  ///
+  /// Remote data tracks are handled separately via @ref handleDataTrackUnpublished.
   ///
   /// @param participant_identity Identity of the remote participant.
   /// @param source               Track source associated with the subscription.