Multimedia communication Essay

Submitted By richboy3
Words: 552
Pages: 3

1) How to change the frame rate of playback to 25 frames per second in the program?

The frame rate can be changed by editing the source code of the Server.jave and changing the variable FRAME_PERIOD to 25.

2) What is the size of the RTP header?

The size of the RTP header is the size of the variable HEAD_SIZE, which was initialized to 12.

3) What kind of information is contained in the RTP packet header?
The information contained in the RTP packet header can be classified into 2
1) Default header field: This field includes

Version = 2
Padding = 0
Extension = 0
CC = 0
Marker = 0
Ssrc = 0

2) Changing header field

Sequence Number
Timestamp
PayloadType 4) How to generate the timestamp information for each RTP packet?

Timestamps are used to place the incoming video packet in the correct order. If an application can or it is sure that it is transmitting every frame with a fixed frame rate, the timestamp is governed by the nominal frame rate. If a frame is transmitted as several RTP packets, these packets would all bear the same timestamp. If the frame number cannot be determined or if frames are sampled a-periodically, as is typically the case for software codecs, the timestamp has to be computed from the system clock. Timestamp clock continues to increase at constant rate when source is inactive
5) What kind of socket is used to transfer rtsp message, udp or tcp? What kind of information is passed when using udp/tcp socket programming for rtsp?
The section of the code that read:
ServerSocket listenSocket = new ServerSocket(RTSPport); theServer.RTSPsocket = listenSocket.accept(); listenSocket.close(); Specifies the use of TCP
RTSP is a companion protocol for RTP which is doing the actual work of the media transport. RTSP covers all aspects for the control of an RTP streaming session. A player connects to the RTSP connection handler of a streaming server and exchanges RTSP requests with the server RTSP requests are used to select the streams which the client would like to play, query the format of the stream (codecs) and the transport method (for example UDP or TCP based), start and stop a streaming session

6) What kind of socket is used to transfer…