lavc: add AV_PKT_DATA_SUBTITLE_POSITION side data type.

This commit introduces a new packet side data type for the subtitle
position information. This is meant to be used by the SRT format where
that information is stored along with the timing, which is not part of
the subrip packets.

libavcodec/avcodec.h

@@ -948,6 +948,17 @@ enum AVPacketSideDataType {
      * the list, so it is required to rely on the side data size to stop.
      */
     AV_PKT_DATA_STRINGS_METADATA,
+
+    /**
+     * Subtitle event position
+     * @code
+     * u32le x1
+     * u32le y1
+     * u32le x2
+     * u32le y2
+     * @endcode
+     */
+    AV_PKT_DATA_SUBTITLE_POSITION,
 };
 
 typedef struct AVPacket {

libavcodec/version.h

@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 54
-#define LIBAVCODEC_VERSION_MINOR 68
+#define LIBAVCODEC_VERSION_MINOR 69
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \