add #EXT-X-TARGETDURATION:6000 to total.m3u8,it is need by vlc and ios Safari

@@ -791,6 +791,9 @@ int SrsHlsMuxer::segment_close(string log_desc)
 						<< SRS_CONSTS_LF;
 				ss << "#EXT-X-PLAYLIST-TYPE:VOD" << SRS_CONSTS_LF;
 				ss << "#EXT-X-MEDIA-SEQUENCE:0" << SRS_CONSTS_LF;
+				//write #EXT-X-TARGETDURATION: large enough for the max duration of later ts is unknown
+				ss << "#EXT-X-TARGETDURATION:" << "6000" << SRS_CONSTS_LF;
+
 				srs_verbose("write m3u8 header success.");
 
 			} else {