avcodec: add AV_PKT_DATA_AFD to allow AFD data to be embedded in AVPacket

Create a new AVPacket side data type for Active Format Description,
which mirrors the side data type found in AVFrame.  The primary
use case for this is ensuring AFD gets preserved in the V210
encoder, so that the decklink libavdevice can output AFD.

Signed-off-by: Devin Heitmueller <dheitmueller@ltnglobal.com>
Signed-off-by: Marton Balint <cus@passwd.hu>

doc/APIchanges

@@ -15,6 +15,9 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2018-09-09 - xxxxxxxxxx - lavc 58.29.100 - avcodec.h
+  Add AV_PKT_DATA_AFD
+
 2018-08-16 - xxxxxxxxxx - lavc 58.23.100 - avcodec.h
   Add av_bsf_flush().
 

libavcodec/avcodec.h

@@ -1365,6 +1365,12 @@ enum AVPacketSideDataType {
      */
     AV_PKT_DATA_ENCRYPTION_INFO,
 
+    /**
+     * Active Format Description data consisting of a single byte as specified
+     * in ETSI TS 101 154 using AVActiveFormatDescription enum.
+     */
+    AV_PKT_DATA_AFD,
+
     /**
      * The number of side data types.
      * This is not part of the public API/ABI in the sense that it may

libavcodec/version.h

@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  58
-#define LIBAVCODEC_VERSION_MINOR  28
+#define LIBAVCODEC_VERSION_MINOR  29
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \