Updated documentation of MPPTaskRunner

mediapipe/tasks/ios/core/sources/MPPTaskRunner.h

@@ -64,15 +64,23 @@ NS_ASSUME_NONNULL_BEGIN
                                         error:(NSError **)error NS_DESIGNATED_INITIALIZER;
 
 /**
- * A synchronous method for processing batch data or offline streaming data. This method is designed
+ * A synchronous method for invoking the C++ task runner for processing batch data or offline
- * for processing either batch data such as unrelated images and texts or offline streaming data
+ * streaming data. This method is designed for processing either batch data such as unrelated images
- * such as the decoded frames from a video file or audio file. The call blocks the current
+ * and texts or offline streaming data such as the decoded frames from a video file or audio file.
- * thread until a failure status or a successful result is returned. If the input packets have no
+ * The call blocks the current thread until a failure status or a successful result is returned. If
- * timestamp, an internal timestamp will be assigend per invocation. Otherwise, when the timestamp
+ * the input packets have no timestamp, an internal timestamp will be assigend per invocation.
- * is set in the input packets, the caller must ensure that the input packet timestamps are greater
+ * Otherwise, when the timestamp is set in the input packets, the caller must ensure that the input
- * than the timestamps of the previous invocation. This method is thread-unsafe and it is the
+ * packet timestamps are greater than the timestamps of the previous invocation. This method is
- * caller's responsibility to synchronize access to this method across multiple threads and to
+ * thread-unsafe and it is the caller's responsibility to synchronize access to this method across
- * ensure that the input packet timestamps are in order.
+ * multiple threads and to ensure that the input packet timestamps are in order.
+ *
+ * @param packetMap A `PacketMap` containing pairs of input stream name and data packet which are to
+ * be sent to the C++ task runner for processing synchronously.
+ * @param error Pointer to the memory location where errors if any should be saved. If @c NULL, no
+ * error will be saved.
+ *
+ * @return An optional output `PacketMap` containing pairs of output stream name and data packet
+ * which holds the results of processing the input packet map, if there are no errors.
  */
 - (std::optional<mediapipe::tasks::core::PacketMap>)
     processPacketMap:(const mediapipe::tasks::core::PacketMap &)packetMap
@@ -84,12 +92,27 @@ NS_ASSUME_NONNULL_BEGIN
  * packets. The caller must ensure that the input packet timestamps are monotonically increasing.
  * This method is thread-unsafe and it is the caller's responsibility to synchronize access to this
  * method across multiple threads and to ensure that the input packet timestamps are in order.
+ *
+ * @param packetMap A `PacketMap` containing pairs of input stream name and data packet that are to
+ * be sent to the C++ task runner for processing asynchronously.
+ * @param error Pointer to the memory location where errors if any should be saved. If @c NULL, no
+ * error will be saved.
+ *
+ * @return A `BOOL` indicating if the live stream data was sent to the C++ task runner successfully.
+ * Please note that any errors during processing of the live stream packet map will only be
+ * available in the user-defined `packetsCallback` that was provided during initialization of the
+ * `MPPVisionTaskRunner`.
  */
 - (BOOL)sendPacketMap:(const mediapipe::tasks::core::PacketMap &)packetMap error:(NSError **)error;
 
 /**
  * Shuts down the C++ task runner. After the runner is closed, any calls that send input data to the
  * runner are illegal and will receive errors.
+ * 
+ * @param error Pointer to the memory location where errors if any should be saved. If @c NULL, no
+ * error will be saved.
+ * 
+ * @return A `BOOL` indicating if the C++ task runner was shutdown successfully.
  */
 - (BOOL)closeWithError:(NSError **)error;