RTSP/RTP streaming support for MPlayer

The Open Source "MPlayer" media player can now receive and play standards-compliant RTP audio/video streams, using the "LIVE555 Streaming Media" source code libraries.

Note: We now recommend the use of the VLC media player. VLC, like MPlayer, uses the "LIVE555 Streaming Media" code for RTSP client support, but is generally more reliable than MPlayer. The VLC web site also has pre-built binary versions; you may not need to build it from source code.

Building MPlayer to support RTSP/RTP streaming

Please do the following steps, in order:
  1. Download and build the "LIVE555 Streaming Media" libraries. You may wish to move the resulting "live/" directory to "/usr/local/", "/usr/local/lib/", or "/usr/lib/". (Note: If you do this, you must move the entire "live/" directory - not just the library files.)
  2. Download the newest version of the MPlayer source code.
  3. If, in Step 1, you moved the "live/" directory to "/usr/local/", "/usr/local/lib/", or "/usr/lib/", run 
        cd MPlayer* ; ./configure
    and check to see whether the "live555" library was automaticaly detected. Otherwise, run 
        cd MPlayer* ; ./configure --extracflags=-I <path-to-LIVE555-Streaming-Media-library-directory>
  4. Now, build and install MPlayer as usual - i.e., 
        make ; make install
    (Note that you must build MPlayer with the same version of "gcc" that you used to build the LIVE555 Streaming Media code.)

Running the new MPlayer

MPlayer can be run just as before. However, it can now open "rtsp://" URLs: 
    mplayer rtsp://<servername>/<filename>
Alternatively, using a "sdp://" pseudo-URL, MPlayer can read a SDP file that describes a RTP session: 
    mplayer sdp://<SDP-filename>
(SDP files are usually used only for playing multicast RTP sessions.)

Audio/Video synchronization

MPlayer's "A-V:" display (at the bottom of the console window) shows the current time difference (in seconds) between the audio and video streams. MPlayer will automatically attempt to synchronize audio and video - i.e., to bring the "A-V:" number close to zero - using information provided by incoming RTCP "Sender Report" packets. Sometimes, however, MPlayer's default synchronization mechanism can be slow to respond. If you need to make it respond more aggressively, try adding the option 
    -mc 10

MPlayer's principal author has also written an informative article that discusses techniques for tuning the performance of MPlayer.

Streaming over TCP

By default, incoming data (RTP and RTCP packets) are streamed using UDP. If, however, you have a broken Internet connection that (for whatever reason) does not pass incoming UDP packets, then you can ask that the incoming data be streamed over TCP instead. (It will use the same TCP connection as RTSP.)

To do this, add the option 

    -rtsp-stream-over-tcp
to MPlayer. (Note that TCP streaming can be used only with "rtsp://" URLs; it can't be used with sessions that are specified using a SDP file.)

Streaming access-controlled RTSP sessions

Some RTSP servers require user authentication (via a name and password) before a session can be streamed. To stream such a session, use the "-user <username> -passwd <password>" options. The program authenticates using RTSP "digest authentication"; the password will not get sent in the clear over the net.

Alternatively, you could try including the user name and password inside the URL, as: "rtsp://<username>:<password>@<hostname>:<etc.>". (In this case, though, the password will be sent in the clear over the net.)

Playing SIP (IP telephony) sessions

MPlayer can also open and play SIP IP telephony sessions - i.e., those specified by a "sip:" URL. Of course, because MPlayer is a receive-only application, you can listen in on such sessions - but you won't be able to talk back. (For two-way communication on a SIP session, you should instead use a dedicated SIP 'softphone' application, such as linphone.)

A note about RealAudio and RealVideo sessions

Note that the LIVE555 Streaming Media libraries do not support RealAudio and/or RealVideo streams - even those described by a "rtsp://" URL - because these streams do not use RTP for transport. (Instead, these streams use RealNetworks' proprietary "RDT" protocol.)

Recently, however, MPlayer was updated so that it can play RealAudio/RealVideo "rtsp://" streams. It does this by first checking whether the URL ends with ".rm" or ".ra". If it does, it handles it as a special case, not using the LIVE555 Streaming Media support. Otherwise, it uses the LIVE555 Streaming Media support, as usual.

Support

General questions about MPlayer should be posted to one of the MPlayer mailing lists. However, questions specifically about the RTSP/RTP streaming support (except for playing RealAudio or RealVideo streams) should be posted instead to the "LIVE555 Streaming Media" developers' mailing list.

Work still to be done...

LIVE555.COM