matroskaenc: ensure the written colorspace don't depend on host endianness

libavformat/matroskaenc.c

@@ -615,8 +615,10 @@ static int mkv_write_tracks(AVFormatContext *s)
                     put_ebml_uint(pb, MATROSKA_ID_VIDEODISPLAYUNIT, 3);
                 }
 
-                if (codec->codec_id == CODEC_ID_RAWVIDEO)
-                    put_ebml_binary(pb, MATROSKA_ID_VIDEOCOLORSPACE, &codec->codec_tag, 4);
+                if (codec->codec_id == CODEC_ID_RAWVIDEO) {
+                    uint32_t color_space = av_le2ne32(codec->codec_tag);
+                    put_ebml_binary(pb, MATROSKA_ID_VIDEOCOLORSPACE, &color_space, sizeof(color_space));
+                }
                 end_ebml_master(pb, subinfo);
                 break;