+ /**
+ * An array of side data that applies to the whole stream (i.e. the
+ * container does not allow it to change between packets).
+ *
+ * There may be no overlap between the side data in this array and side data
+ * in the packets. I.e. a given side data is either exported by the muxer
+ * (demuxing) / set by the caller (muxing) in this array, then it never
+ * appears in the packets, or the side data is exported / sent through
+ * the packets (always in the first packet where the value becomes known or
+ * changes), then it does not appear in this array.
+ *
+ * - demuxing: Set by libavformat when the stream is created.
+ * - muxing: May be set by the caller before avformat_write_header().
+ *
+ * Freed by libavformat in avformat_free_context().
+ */
+ AVPacketSideData *side_data;
+ /**
+ * The number of elements in the AVStream.side_data array.
+ */
+ int nb_side_data;
+
+ /**
+ * Flags for the user to detect events happening on the stream. Flags must
+ * be cleared by the user once the event has been handled.
+ * A combination of AVSTREAM_EVENT_FLAG_*.
+ */
+ int event_flags;
+#define AVSTREAM_EVENT_FLAG_METADATA_UPDATED 0x0001 ///< The call resulted in updated metadata.
+