matroskaenc: write private data in hvcC format for HEVC.

libavformat/Makefile

@@ -168,7 +168,7 @@ OBJS-$(CONFIG_M4V_MUXER)                 += rawenc.o
 OBJS-$(CONFIG_MATROSKA_DEMUXER)          += matroskadec.o matroska.o  \
                                             isom.o rmsipr.o
 OBJS-$(CONFIG_MATROSKA_MUXER)            += matroskaenc.o matroska.o \
-                                            isom.o avc.o \
+                                            isom.o avc.o hevc.o \
                                             flacenc_header.o avlanguage.o wv.o
 OBJS-$(CONFIG_MD5_MUXER)                 += md5enc.o
 OBJS-$(CONFIG_MJPEG_DEMUXER)             += rawdec.o

libavformat/matroskaenc.c

@@ -22,6 +22,7 @@
 #include <stdint.h>
 
 #include "avc.h"
+#include "hevc.h"
 #include "avformat.h"
 #include "avlanguage.h"
 #include "flacenc.h"
@@ -500,6 +501,8 @@ static int mkv_write_codecprivate(AVFormatContext *s, AVIOContext *pb, AVCodecCo
             ret = put_wv_codecpriv(dyn_cp, codec);
         else if (codec->codec_id == AV_CODEC_ID_H264)
             ret = ff_isom_write_avcc(dyn_cp, codec->extradata, codec->extradata_size);
+        else if (codec->codec_id == AV_CODEC_ID_HEVC)
+            ret = ff_isom_write_hvcc(dyn_cp, codec->extradata, codec->extradata_size, 0);
         else if (codec->codec_id == AV_CODEC_ID_ALAC) {
             if (codec->extradata_size < 36) {
                 av_log(s, AV_LOG_ERROR,