+ if (tag = av_dict_get(s->metadata, "creation_time", NULL, 0)) {
+ // Adjust time so it's relative to 2001-01-01 and convert to nanoseconds.
+ int64_t date_utc = (ff_iso8601_to_unix_time(tag->value) - 978307200) * 1000000000;
+ uint8_t date_utc_buf[8];
+ AV_WB64(date_utc_buf, date_utc);
+ put_ebml_binary(pb, MATROSKA_ID_DATEUTC, date_utc_buf, 8);
+ }
+