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Lecture 5 and 6 notes:

Lecture 5 and 6 notes:. Reji Mathew & Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2009. Sender Side Issues Conforming to Network Bandwidth Adaptive Rate Control Error Resilience Packetization strategy. Receiver Side Issues Buffering input data Error concealment

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Lecture 5 and 6 notes:

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  1. Lecture 5 and 6 notes: Reji Mathew & Jian Zhang NICTA & CSE UNSW COMP9519 Multimedia Systems S2 2009

  2. Sender Side Issues • Conforming to Network Bandwidth • Adaptive Rate Control • Error Resilience • Packetization strategy • Receiver Side Issues • Buffering input data • Error concealment • Inter media synchronization System Overview MPEG-4 File / Encoder MPEG-4 Video packetize Decoder RTCP RTP RTCP RTP UDP UDP IP

  3. increased when a modification is made to the session data. Recommended that an NTP timestamp is used SDP Version number v=0 o=NICTA 2890844526 2890842807 IN IP4 129.94.135.201 s=Camera ONE i=Video stream for realtime surveillance u=http://www.nicta.com/mmvc/demos/SurveillanceVideo.pdf e=jian.zhang@nicta.com.au (Jian Zhang) c=IN IP4 225.0.0.37/2 t=0 0 a=recvonly m=video 20000 RTP/AVP 98 a=rtpmap:98 MP4V-ES/90000 a=fmtp:98 profile-level-id=1; config=000001b001000001… a=orient:portrait Originator information <username> <session id> <version> <network type> <address type> <address> (address of machine from which the session was created) Session name Session Information (text description / title for session) URL for more information about the session Contact person e-mail (person responsible not necessarily the creator) Connection Details <network type> <address type> <connection address> IN (internet) IP4 (IP v4) address (multicast address/TTL) Time Information <start time> <end time> (ntp time, “0,0” implies permanent session) Session level attribute (operate in receive only mode) Media Announcement <media> <port> <transport> <fmt list> (fmt : refers to media format specific information) (e.g. Dynamic payload number) Media attribute (rtp map) <payload type> <encoding name>/<clock rate> (map RTP dynamic payload number to media format and clock rate) Media attribute (format specific parameters) (info regarding mpeg-4 media, profile, level & initialization data) Media attribute (orientation) (only used in some applications, example – landscape or portrait)

  4. Version Presentation URL Method CSeq header field Sequence number for an RTSP request-response pair Must be present in all requests and responses Aggregate control possible (session level control attribute) RTSP : Describe Method • Retrieves the description of a presentation, identified by the request URL, from a server. The DESCRIBE reply-response pair constitutes the media initialization phase of RTSP. C->S: DESCRIBE rtsp://nicta.com/twister RTSP/1.0 CSeq: 1 Request line S->C: RTSP/1.0 200 OK CSeq: 1 Content-Type: application/sdp Content-Length: 164 v=0 o=- 2890844256 2890842807 IN IP4 172.16.2.93 s=RTSP Session i=An Example of RTSP Session Usage a=control:rtsp://nicta.com/twister t=0 0 m=audio 0 RTP/AVP 0 a=control:rtsp://nicta.com/twister/audio m=video 0 RTP/AVP 26 a=control:rtsp://nicta.com/twister/video Response line: Version, Status code “200” with description Same CSeq number as request SDP Information (message body)

  5. Protocol Stack MPEG-4 File / Encoder MPEG-4 Video packetize SDP Decoder SDP RTCP RTP RTSP RTSP RTCP RTP UDP TCP TCP UDP IP

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