流式視頻服務(wù)器和客戶機的 實現(xiàn)

1、流式視頻服務(wù)器和客戶機的實現(xiàn)1主要內(nèi)容目標和功能采用的方法原理實現(xiàn)2目標和功能實現(xiàn)流式視頻服務(wù)器和客戶機流式存儲視頻應(yīng)用客戶機發(fā)送SETUP,PLAY,PAUSE和TEARDOWN等RTSP命令，并且服務(wù)器應(yīng)答這些命令；當服務(wù)器處于播放狀態(tài)時，它周期性地抓取JPEG幀，用RTP對該幀分組化，并將該RTP分組發(fā)送到一個UDP套接字中；客戶機接收該RTP分組，解壓縮JPEG幀，并在客戶機顯示器上顯示。3采用的方法和原理RTSPRTP4RTSP運行過程5Presentation Description文件例子Twister 6RTSP Exchange Example C: SETUP rtsp:/

2、twister/audio RTSP/1.0 Cseq：1 Transport: rtp/udp; compression; port=3056; mode=PLAY S: RTSP/1.0 200 OK Cseq：1 Session 4231 C: PLAY rtsp:/twister/audio.en/lofi RTSP/1.0 Cseq：2 Range: npt=0- Session: 4231 C: PAUSE rtsp:/twister/audio.en/lofi RTSP/1.0 Cseq：3 Range: npt=37 Session: 4231 C: TEARDOWN rtsp

3、:/twister/audio.en/lofi RTSP/1.0 Cseq：4 Session: 4231 S: RTSP/1.0 200 3 OK Cseq：4 Session: 4231 7RTP runs on top of UDPRTP libraries provide a transport-layer interface that extend UDP: port numbers IP addresses payload type identification packet sequence numbering time-stampingUDPRTP8RTP HeaderPayl

4、oad Type (7 bits): Indicates type of encoding currently being used. If sender changes encoding in middle of conference, sender informs the receiver through this payload type field. Payload type 0: PCM mu-law, 64 kbpsPayload type 3, GSM, 13 kbpsPayload type 7, LPC, 2.4 kbpsPayload type 26, Motion JPE

5、GPayload type 31. H.261Payload type 33, MPEG2 videoSequence Number (16 bits): Increments by one for each RTP packet sent, and may be used to detect packet loss and to restore packet sequence.9RTP Header (2)Timestamp field (32 bytes long). Reflects the sampling instant of the first byte in the RTP data packet. SSRC field (32 bits long). Identifies the source o