Unreal Media Server

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Unreal Media Server
Developer(s) Unreal Streaming Technologies
Stable release 11.0 / April 20, 2015; 6 months ago (2015-04-20)
Operating system Windows
Type streaming server software
License Proprietary
Website www.umediaserver.net/umediaserver

Unreal Media Server is a streaming server software created by Unreal Streaming Technologies.

Streaming protocol support[edit]

  • UMS protocol (proprietary) for streaming to Unreal Streaming Media Player on Windows OS
  • RTMP/RTMPT protocol for streaming to Flash Player on any Flash-enabled OS
  • Apple Http Live Streaming for streaming to iOS and other HLS-enabled devices
  • MS-WMSP protocol for streaming to Silverlight, Windows Media Player
  • MS Smooth streaming protocol for streaming to Silverlight
  • MPEG2-TS protocol for streaming to Set-Top boxes

Proprietary UMS streaming protocol is based on Microsoft DirectShow, and therefore, UMS protocol is codec-independent. UMS protocol realizes a distributed DirectShow graph where source filter resides on the server computer and renderer filter resides on the player computer; a corresponding DirectShow decoder needs to be installed at the player computer/device.

Supported file container formats: MP4, ASF, AVI, MKV, MPEG, WMV, FLV, Ogg, MP3, 3GP, MOV, other containers. Using a DirectShow approach, file content is being demultiplexed from its container for each individual player and being sent to that player via whatever streaming protocol that player needs.

With regards to live video, Unreal Media Server acts as universal transmuxer: it receives live streams muxed in different protocols/formats (RTSP-RTP, MS-WMSP/ASF, MPEG2-TS, UMS), demuxes (extracts) the actual elementary streams from these containers, and muxes (packages) it for specific player delivery. For example, it can take a live RTSP stream from IP camera and re-mux it into RTMP/FLV protocol/format when Adobe Flash Player asks for live video; at the same time re-mux it to MPEG2-TS for delivery to Set-Top box, and at the same time send it to iOS devices with HLS protocol. Unreal Media Server is known for low latency live streaming; with UMS, RTMP and MPEG2-TS protocols latencies of 0.2–2 seconds can be achieved when streaming over the Internet; with Apple HLS the latency can be as low as 2.5 seconds.


A first version of Unreal Media Server, released in October 2003, supported proprietary UMS protocol only. At that time this was the only server capable of streaming AVI files without transcoding;[1] the first version was completely free.[2] In the next versions additional streaming protocols such as MS-WMSP(MMS) and RTMP were added .[3] Also, a free version introduced a limit of 15 concurrent connections and a commercial version was offered for purchase.[4] Before version 9.0 the Server accepted live streams from proprietary encoder named Unreal Live Server only. With version 9.0 the ability of digesting of RTSP, MPEG2-TS and MMS live streams was introduced, to support industry standard live encoders such as IP network cameras, Windows Media Encoder etc.; version 10.0 added support for Flash encoders such as FMLE. Version 10.5 added support for adaptive bitrate streaming; also, limit of concurrent connections in a free version was reduced to 10 connections. Version 11.0 added time-shifted playback for live broadcasts, for up to 12 hours back from real-time.


External links[edit]