avcodec/packet: add a Gain Map parameters side data type

Mirroring the frame one. Will be used by demuxers as stream or stream group
side data.

Signed-off-by: James Almer <jamrial@gmail.com>

doc/APIchanges

@@ -2,6 +2,9 @@ The last version increases of all libraries were on 2026-06-23.
 
 API changes, most recent first:
 
+2026-10-12 - xxxxxxxxxx - lavc 63.19.100 - packet.h
+  Add AV_PKT_DATA_GAIN_MAP_PARAMS.
+
 2026-10-12 - xxxxxxxxxx - lavf 63.10.100 - avformat.h
   Add AVStreamGroupEntry
   Add AV_STREAM_GROUP_ENTRY_STREAM and AV_STREAM_GROUP_ENTRY_STREAM_GROUP

libavcodec/avcodec.c

@@ -66,6 +66,7 @@ const SideDataMap ff_sd_global_map[] = {
     { AV_PKT_DATA_AMBIENT_VIEWING_ENVIRONMENT,AV_FRAME_DATA_AMBIENT_VIEWING_ENVIRONMENT },
     { AV_PKT_DATA_3D_REFERENCE_DISPLAYS,      AV_FRAME_DATA_3D_REFERENCE_DISPLAYS },
     { AV_PKT_DATA_EXIF,                       AV_FRAME_DATA_EXIF },
+    { AV_PKT_DATA_GAIN_MAP_PARAMS,            AV_FRAME_DATA_GAIN_MAP_PARAMS },
     { AV_PKT_DATA_NB },
 };
 

libavcodec/packet.c

@@ -312,6 +312,7 @@ const char *av_packet_side_data_name(enum AVPacketSideDataType type)
     case AV_PKT_DATA_RTCP_SR:                    return "RTCP Sender Report";
     case AV_PKT_DATA_EXIF:                       return "EXIF metadata";
     case AV_PKT_DATA_HEVC_CONF:                  return "HEVC enhancement-layer decoder configuration";
+    case AV_PKT_DATA_GAIN_MAP_PARAMS:            return "Gain Map Parameters";
     }
     return NULL;
 }

libavcodec/packet.h

@@ -383,6 +383,13 @@ enum AVPacketSideDataType {
      */
     AV_PKT_DATA_HEVC_CONF,
 
+    /**
+     * Parameters describing how to combine this gain map with its base image
+     * to form an alternate rendition. The payload is the AVGainMapParams
+     * struct defined in libavutil/gain_map.h.
+     */
+    AV_PKT_DATA_GAIN_MAP_PARAMS,
+
     /**
      * The number of side data types.
      * This is not part of the public API/ABI in the sense that it may

libavcodec/version.h

@@ -29,8 +29,8 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR  18
-#define LIBAVCODEC_VERSION_MICRO 101
+#define LIBAVCODEC_VERSION_MINOR  19
+#define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \