1.OPTION
目的是得到服務器提供的可用方法:
OPTIONS rtsp://192.168.20.136:5000/xxx666 RTSP/1.0
CSeq: 1 //每個消息都有序號來標記,第一個包通常是option請求消息
User-Agent: VLC media player (LIVE555 Streaming Media v2005.11.10)
服務器的迴應信息包括提供的一些方法,例如:
RTSP/1.0 200 OK
Server: UServer 0.9.7_rc1
Cseq: 1 //每個迴應消息的cseq數值和請求消息的cseq相對應
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE, SCALE,
GET_PARAMETER //服務器提供的可用的方法
2.DESCRIBE
C向S發起DESCRIBE請求,爲了得到會話描述信息(SDP):
DESCRIBE rtsp://192.168.20.136:5000/xxx666 RTSP/1.0
CSeq: 2
token:
Accept: application/sdp
User-Agent: VLC media player (LIVE555 Streaming Media v2005.11.10)
服務器迴應一些對此會話的描述信息(sdp):
RTSP/1.0 200 OK
Server: UServer 0.9.7_rc1
Cseq: 2
x-prev-url: rtsp://192.168.20.136:5000
x-next-url: rtsp://192.168.20.136:5000
x-Accept-Retransmit: our-retransmit
x-Accept-Dynamic-Rate: 1
Cache-Control: must-revalidate
Last-Modified: Fri, 10 Nov 2006 12:34:38 GMT
Date: Fri, 10 Nov 2006 12:34:38 GMT
Expires: Fri, 10 Nov 2006 12:34:38 GMT
Content-Base: rtsp://192.168.20.136:5000/xxx666/
Content-Length: 344
Content-Type: application/sdp
v=0 //以下都是sdp信息
o=OnewaveUServerNG 1451516402 1025358037 IN IP4 192.168.20.136
s=/xxx666
u=http:///
e=admin@
c=IN IP4 0.0.0.0
t=0 0
a=isma-compliance:1,1.0,1
a=range:npt=0-
m=video 0 RTP/AVP 96 //m表示媒體描述,下面是對會話中視頻通道的媒體描述
a=rtpmap:96 MP4V-ES/90000
a=fmtp:96
profile-level-id=245;config=000001B0F5000001B509000001000000012000C888B0E0E0FA62D089028307
a=control:trackID=0//trackID=0表示視頻流用的是通道0
3.SETUP
客戶端提醒服務器建立會話,並確定傳輸模式:
SETUP rtsp://192.168.20.136:5000/xxx666/trackID=0 RTSP/1.0
CSeq: 3
Transport: RTP/AVP/TCP;unicast;interleaved=0-1
User-Agent: VLC media player (LIVE555 Streaming Media v2005.11.10)
//uri中帶有trackID=0,表示對該通道進行設置。Transport參數設置了傳輸模式,包
的結構。接下來的數據包頭部第二個字節位置就是interleaved,它的值是每個通道都
不同的,trackID=0的interleaved值有兩個0或1,0表示rtp包,1表示rtcp包,接受端
根據interleaved的值來區別是哪種數據包。
服務器迴應信息:
RTSP/1.0 200 OK
Server: UServer 0.9.7_rc1
Cseq: 3
Session: 6310936469860791894 //服務器迴應的會話標識符
Cache-Control: no-cache
Transport: RTP/AVP/TCP;unicast;interleaved=0-1;ssrc=6B8B4567
4.PLAY
客戶端發送播放請求:
PLAY rtsp://192.168.20.136:5000/xxx666 RTSP/1.0
CSeq: 4
Session: 6310936469860791894
Range: npt=0.000- //設置播放時間的範圍
User-Agent: VLC media player (LIVE555 Streaming Media v2005.11.10)
服務器迴應信息:
RTSP/1.0 200 OK
Server: UServer 0.9.7_rc1
Cseq: 4
Session: 6310936469860791894
Range: npt=0.000000-
RTP-Info: url=trackID=0;seq=17040;rtptime=1467265309
//seq和rtptime都是rtp包中的信息
5.TEARDOWN
客戶端發起關閉請求:
TEARDOWN rtsp://192.168.20.136:5000/xxx666 RTSP/1.0
CSeq: 5
Session: 6310936469860791894
User-Agent: VLC media player (LIVE555 Streaming Media v2005.11.10)
服務器迴應:
RTSP/1.0 200 OK
Server: UServer 0.9.7_rc1
Cseq: 5
Session: 6310936469860791894
Connection: Close
以上方法都是交互過程中最爲常用的,其它還有一些重要的方法如
get/set_parameter,pause,redirect等等
ps:
sdp的格式
v=<version>
o=<username> <session id> <version> <network type> <address type> <address>
s=<session name>
i=<session description>
u=<URI>
e=<email address>
p=<phone number>
c=<network type> <address type> <connection address>
b=<modifier>:<bandwidth-value>
t=<start time> <stop time>
r=<repeat interval> <active duration> <list of offsets from start-time>
z=<adjustment time> <offset> <adjustment time> <offset> ....
k=<method>
k=<method>:<encryption key>
a=<attribute>
a=<attribute>:<value>
m=<media> <port> <transport> <fmt list>
v = (協議版本)
o = (所有者/創建者和會話標識符)
s = (會話名稱)
i = * (會話信息)
u = * (URI 描述)
e = * (Email 地址)
p = * (電話號碼)
c = * (連接信息)
b = * (帶寬信息)
z = * (時間區域調整)
k = * (加密密鑰)
a = * (0 個或多個會話屬性行)
時間描述:
t = (會話活動時間)
r = * (0或多次重複次數)
媒體描述:
m = (媒體名稱和傳輸地址)
i = * (媒體標題)
c = * (連接信息 — 如果包含在會話層則該字段可選)
b = * (帶寬信息)
k = * (加密密鑰)
a = * (0 個或多個媒體屬性行)
參考文章:rfc2326(rtsp);rfc2327(sdp)
RTSP點播消息流程實例(客戶端:VLC, RTSP服務器:LIVE555 Media Server)
1)C(Client)-> M(Media Server)
OPTIONS rtsp://192.168.1.109/1.mpg RTSP/1.0
CSeq: 1
user-Agent: VLC media player(LIVE555 Streaming Media v2007.02.20)
1)M -> C
RTSP/1.0 200 OK
CSeq: 1
Date: wed, Feb 20 2008 07:13:24 GMT
Public: OPTIONS, DESCRIBE, SETUP, TEARDOWN, PLAY, PAUSE
2)C -> M
DESCRIBE rtsp://192.168.1.109/1.mpg RTSP/1.0
CSeq: 2
Accept: application/sdp
User-Agent: VLC media player(LIVE555 Streaming Media v2007.02.20)
2)M -> C
RTSP/1.0 200 OK
CSeq: 2
Date: wed, Feb 20 2008 07:13:25 GMT
Content-Base: rtsp://192.168.1.109/1.mpg/
Content-type: application/sdp
Content-length: 447
v=0
o =- 2284269756 1 IN IP4 192.168.1.109
s=MPEG-1 or 2 program Stream, streamed by the LIVE555 Media Server
i=1.mpg
t=0 0
a=tool:LIVE555 Streaming Media v2008.02.08
a=type:broadcast
a=control:*
a=range:npt=0-66.181
a=x-qt-text-nam:MPEG-1 or Program Stream, streamed by the LIVE555 Media Server
a=x-qt-text-inf:1.mpg
m=video 0 RTP/AVP 32
c=IN IP4 0.0.0.0
a=control:track1
m=audio 0 RTP/AVP 14
c=IN IP4 0.0.0.0
a=control:track2
3)C -> M
SETUP rtsp://192.168.1.109/1.mpg/track1 RTSP/1.0
CSeq: 3
Transport: RTP/AVP; unicast;client_port=1112-1113
User-Agent: VLC media player(LIVE555 Streaming Media v2007.02.20)
3)M -> C
RTSP/1.0 200 OK
CSeq: 3
Date: wed, Feb 20 2008 07:13:25 GMT
Transport: RTP/AVP;unicast;destination=192.168.1.222;source=192.168.1.109;client_port=1112-1113;server_port=6970-6971
Session: 3
4)C -> M
SETUP rtsp://192.168.1.109/1.mpg/track2 RTSP/1.0
CSeq: 4
Transport: RTP/AVP; unicast;client_port=1114-1115
Session: 3
User-Agent: VLC media player(LIVE555 Streaming Media v2007.02.20)
4)M -> C
RTSP/1.0 200 OK
CSeq: 4
Date: wed, Feb 20 2008 07:13:25 GMT
Transport: RTP/AVP;unicast;destination=192.168.1.222;source=192.168.1.109;client_port=1114-1115;server_port=6972-6973
Session: 3
5)C -> M
PLAY rtsp://192.168.1.109/1.mpg/ RTSP/1.0
CSeq: 5
Session: 3
Range: npt=0.000-
User-Agent: VLC media player(LIVE555 Streaming Media v2007.02.20)
5)M -> C
RTSP/1.0 200 OK
CSeq: 5
Range: npt=0.000-
Session: 3
RTP-Info: url=rtsp://192.168.1.109/1.mpg/track1;seq=9200;rtptime=214793785,url=rtsp://192.168.1.109/1.mpg/tr