1. 流式视频服务器和客户机的 实现 钱叶魁

2. 主要内容 目标和功能 采用的方法原理 实现

3. 目标和功能 实现流式视频服务器和客户机 — 流式存储视频应用 客户机发送 SETUP,PLAY,PAUSE 和 TEARDOWN 等 RTSP 命 令，并且服务器应答这些命令； 当服务器处于播放状态时，它周期性地抓取 JPEG 帧，用 RTP 对该帧分组化，并将该 RTP 分组发送到一个 UDP 套接 字中； 客户机接收该 RTP 分组，解压缩 JPEG 帧，并在客户机显示 器上显示。

4. 采用的方法和原理 RTSP RTP

5. RTSP 运行过程

6. Presentation Description 文件例子 Twister <track type=audio e="PCMU/8000/1" src = "rtsp://audio.example.com/twister/audio.en/lofi"> <track type=audio e="DVI4/16000/2" pt="90 DVI4/8000/1" src="rtsp://audio.example.com/twister/audio.en/hifi"> <track type="video/jpeg" src="rtsp://video.example.com/twister/video">

7. RTSP Exchange Example C: SETUP rtsp://audio.example.com/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://audio.example.com/twister/audio.en/lofi RTSP/1.0 Cseq ： 2 Range: npt=0- Session: 4231 C: PAUSE rtsp://audio.example.com/twister/audio.en/lofi RTSP/1.0 Cseq ： 3 Range: npt=37 Session: 4231 C: TEARDOWN rtsp://audio.example.com/twister/audio.en/lofi RTSP/1.0 Cseq ： 4 Session: 4231 S: RTSP/1.0 200 3 OK Cseq ： 4 Session: 4231

8. RTP runs on top of UDP RTP libraries provide a transport-layer interface that extend UDP: port numbers IP addresses payload type identification packet sequence numbering time-stamping UDP RTP

9. RTP Header Payload 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 kbps Payload type 3, GSM, 13 kbps Payload type 7, LPC, 2.4 kbps Payload type 26, Motion JPEG Payload type 31. H.261 Payload type 33, MPEG2 video Sequence Number (16 bits): Increments by one for each RTP packet sent, and may be used to detect packet loss and to restore packet sequence.

10. RTP 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 of the RTP stream. Each stream in a RTP session should have a distinct SSRC.

11. 实现