Streaming

Outline

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165

4 3

Introduction DefinitionStreaming

architectures & typesServices & applicationsProtocolsConclusions

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Demonstration

Introduction

• The first generation of web pages was only made with text.

• Nowadays multimedias take an important part in most web application.

• There was a problem in the quality of multimedia transfer by the internet.

Streaming is set to transform the World Wide Web: video and audio are accepted as the most natural way to communicate.

Solution

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What’s Streaming ?

• streaming : transmit audio & video and other

multimedia over the internet without making

viewer waiting.

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How streaming video & audio works ?

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Streaming architecture

Multicast

Unicast

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Streaming Types (1/2)

Pseudo Streaming

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Streaming Types (2/2)

Streaming

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Streaming Services

• Education (E-learning)

• Web-based channels (Web TV, Web monitoring,Internet radio)

• Video-on-demand (VOD)

• Music distribution (music on-demand)

• Internet and intranet browsing of content (asset management)

• Internet broadcasting (corporate communications)

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Principle Streaming

Streaming is based primarily on:

• Broadcast a video of a server to a client.

• Segmentation of the video.

• Assemble packets.

• The video is played on as the packets arrive.

• At the end these packets are then destroyed.

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Streaming Applications

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Streaming Protocols :

There are currently three protocols that allow for streaming:

• HTTP.

• FTP.

• RTP.

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Streaming Protocols : RTP(1/2)

RTP (Real Time Protocol) :

• RTP was created in 1996 and was defined in RFC 1889

to define functions in real time as the broadcast audio

and / or video.

• The principle of RTP is to send packets in real time on

the network.

• This packets are marked temporally so as to be

rescheduled by the client.

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Streaming Protocol :RTP(2/2)

• Sequence number : detect packet loss ,sequences loss in the correct order.

• Timestamp : Synchronization & jitter calculation.

Header IP Header UDP Header RTP Audio & Video Data

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Streaming Protocols : RTSP(1/2)

RTSP (Real Time Streaming Protocol):

• RTSP was created in 1998 by RFC 2326 allows to

control multimedia streams delivered via RTP.

• RTSP is an application layer protocol designed to

operate on protocols such as RTP/RTCP and RSVP.

• It can control the distribution of multimedia streams.

• It provides VCR-like functions remotely like: – Reading.– Pause.– Stop.

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Streaming Protocols : RTSP(2/2)

Setup Start an RTSP session and resource allocation for a stream

Play and Record Start data transmission of the stream

Pause Temporarily halt a stream without freeing server resources

Teardown Free resources associated with stream and end of a session

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Streaming Protocols :RTCP

• RTCP : Real time Control Protocol

• RTCP is used in conjunction with RTP.

• Feed back on the quality of service (reports : nbre packets , lost , statistics)

• The feedback messages include reports, such as number of packets lost and jitter statistics (early or late arrivals).

Recognition of flaws.

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Conclusion

Streaming allows us to continue to use applications where off-line (as opposed to pure web-applications).

It allows the optimization of software licensing.

The maintenance of streaming server is relatively expensive

It is difficult to keep the service steady if the bandwidth is low

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Demonstration

Thank you for your attention