Difference between revisions of "Windows Media streaming"

Revision as of 15:34, 18 December 2008

About Windows Media

Windows Media is a format for lossy audio and video transmission by Microsoft. The audio format is known as WMA (file extension .wma).

In streaming WMA is transferred over a protocol called MMS.

MMS disambiguation

The name MMS (Microsoft Media Server) is a bit confusing as it is often used to describe different protocols.

There are three protocols often called as MMS based on a similar protocol: MMS over HTTP, MMS over TCP and MMS over UDP.

The Streaming Client supports MMS over TCP and MMS over HTTP. For these protocols the following URL prefixes are commonly used: http://, mms:// and mmst://

For even more confusion the http:// prefix is widely used for Shoutcast servers.

The following table explains the URL prefixes used by the Streaming Client:

Protocol	Prefix used by the Streaming Client	Commonly used prefix
Shoutcast	http://	http://
MMS over HTTP	mms://	http://
MMS over TCP	mmst://	mms:// or mmst://

MMS in the Streaming Client

Until February 2008 the MMS protocol was proprietary and the only way to implement non-Microsoft player was to reverse-engineer the protocol. In February 2008 Microsoft deprecated the MMS in favor of RTSP and released the MMS specifications to the public.

Limitations

The Streaming Client implementation still uses the reverse-engineered protocol and therefore is not 100% compatible with all servers. The Streaming Client supports audio-only streams (some streams are mixed video and audio) and only streams with one bitrate (some servers send multiple bitrates at the same time).

Shall I use MMS or MMST?

If you get a URL use the above table to select the proper protocol in the Streaming Client.

Most Windows based internet radio servers stream in MMS over HTTP. Therefore try this option first.

Most servers also provide both MMS over HTTP and MMS over TCP, but it is not automatically in all cases (must be enabled on the server). If you own the server and can configure it, allow both options.

If MMS over HTTP does not work or you experience problems try MMS over TCP and vice versa. However, MMS over HTTP should be more reliable.

@@ Line 1: / Line 1: @@
 == About Windows Media ==
-Windows Media is a format for lossy audio and video transmission by Microsoft. The audio format is known as WMA (file extension .wma).
+Windows Media is a format for lossy audio and video transmission by Microsoft. The audio format is known as [[wikipedia:WMA|WMA]] (file extension .wma).
 In streaming WMA is transferred over a protocol called MMS.
 == MMS disambiguation ==
-The name [[w:Microsoft_Media_Services|MMS (Microsoft Media Server)]] is a bit confusing as it is often used to describe different protocols.
+The name [[wikipedia:Microsoft_Media_Services|MMS (Microsoft Media Server)]] is a bit confusing as it is often used to describe different protocols.
 There are three protocols often called as MMS based on a similar protocol: MMS over HTTP, MMS over TCP and MMS over UDP.
@@ Line 11: / Line 12: @@
 The Streaming Client supports MMS over TCP and MMS over HTTP. For these protocols the following URL prefixes are commonly used: '''http://''', '''mms://''' and '''mmst://'''
-For even more confusion the '''http://''' prefix is widely used for [[w:Shoutcast]] servers.
+For even more confusion the '''http://''' prefix is widely used for [[wikipedia:Shoutcast|Shoutcast]] servers.
 The following table explains the URL prefixes used by the Streaming Client:
@@ Line 33: / Line 34: @@
 |}
-== Streaming Client ==
-Windows Media
-This confusion with prefixes comes from Microsoft, those are basically two different protocols often called only MMS.
+== MMS in the Streaming Client ==
-The prefix mms:// stands for MMS over HTTP. Quite often it has also the prefix http:// - but do not confuse this with Shoutcast which uses also http://
+Until February 2008 the MMS protocol was proprietary and the only way to implement non-Microsoft player was to reverse-engineer the protocol. In February 2008 Microsoft deprecated the MMS in favor of RTSP and released the MMS specifications to the public.
-The prefix mmst:// stands for MMS over TCP, sometimes also called only mms://
-You have to enable each service on the Windows server - some radio stations provide only MMS over HTTP and some only MMS over TCP. Not everytime both services are automatically enabled.
+=== Limitations ===
+The Streaming Client implementation still uses the reverse-engineered protocol and therefore is not 100% compatible with all servers. The Streaming Client supports audio-only streams (some streams are mixed video and audio) and only streams with one bitrate (some servers send multiple bitrates at the same time).
+== Shall I use MMS or MMST? ==
+If you get a URL use the above table to select the proper protocol in the Streaming Client.
+Most Windows based internet radio servers stream in MMS over HTTP. Therefore try this option first.
+Most servers also provide both MMS over HTTP and MMS over TCP, but it is not automatically in all cases (must be enabled on the server). If you own the server and can configure it, allow both options.
+If MMS over HTTP does not work or you experience problems try MMS over TCP and vice versa. However, MMS over HTTP should be more reliable.
-Please try the firmware I sent to you in the previous email. The version number is still the same but it contains a fix which helps with certain MMST servers. It is playing here with all three mmst:// streams.
+== Playlists ==