2.2.7.9 Play

The main purpose of the Play request is to ask the server to start streaming RTP packets for the currently selected streams. If the server has switched to a new entry in a server-side playlist and is using predictive stream selection to select streams on the client's behalf, the Play request is also used as a way for the client to confirm the stream selection made by the server and to confirm that it has started to play the RTP packets for the new playlist entry.

The Play request is implemented by using the PLAY request method and MUST adhere to the syntax for PLAY, as specified in [RFC2326] section 10.5, with the following additional constraints:

• The Play request includes the Session header (as specified in [RFC2326] section 12.37).

• The Play request specifies either a Range (section 2.2.6.7) header or an X-Playlist (section 2.2.6.20) header.

• If the stream is a part of a server-side playlist then the Play request includes the X-Playlist-Gen-Id (section 2.2.6.22) header.

For information on predictive stream selection, see section 2.2.6.10.5.

The response to the Play request can include the Cache-Control (section 2.2.6.2) header.

The following example shows a Play request.

 PLAY rtsp://myserver.com/ServerSidePlaylist.wsx RTSP/1.0
 X-Playlist-Seek-Id: 5353
 User-Agent: WMPlayer/9.0.0.2868 guid/832BF8C6-D8E4-40D4-A058-C31F3D4A3B65
 Accept-Charset: UTF-8, *;q=0.1
 X-Accept-Authentication: Negotiate, NTLM, Digest
 Accept-Language: en-us, *;q=0.1
 Session: 13856065358275910855
 CSeq: 8
 Range: npt=0.000-
 Bandwidth: 2147483647
 X-Accelerate-Streaming: AccelDuration=8000;AccelBandwidth=1024128
 X-RTP-Info: url=rtsp://myserver.com/ServerSidePlaylist.wsx/audio,
  url=rtsp://myserver.com/ServerSidePlaylist.wsx/rtx