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Media Streaming 12

Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

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Page 1: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Media Streaming

12

Page 2: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

What is Streaming Media?

The delivery of audio/video/data between a server and a client (user), as a continuous digital stream

Eliminates waiting for an entire file to download

Content is converted to digital files sent over the internet as data packets.

Playback begins as soon as first packets arrive or as requested by the end user

No impact on end-user’s computer

Leading architectures: RealMedia, Windows Media, QuickTime

Page 3: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

It’s a Challenge

Uncompressed digital video produces data at the rate of 27 MB/sec (1.6 GB/min)

A challenge to store

A challenge to transport

Page 4: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Factors in Architecture Selection

Encoder Server Player Tools Encoder Server Player Tools Encoder Server Player ToolsUnix x x x x xWin x x x x x x x x x x x xMac x x x x x x x x x x

Windows Media Real QuickTime

Page 5: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Formats

Major player formats Real Networks

Real Media Player – RM Microsoft

Windows Media Player – WMV Apple

Quicktime Player – MOV

Other formats Audio downloads – MP3 Capture and editing - AVI Flash and animation - SWF CD audio playback – CDA, WAV

Page 6: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Things to Consider

Identify your user audience Player compatibility

Are they using PC or Mac Offices, Dorms, Computer Labs, Homes Wireless and other mobile devices

Internet Connection Low speed – 28kbps to 80kbps High speed – 80kbps to 300kbps Broadband – 300kbps to 1.0mbps

Audience members Staff, Dept. Admins, Managers, Directors Anonymous users on WWW

Page 7: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Things to Consider

Media delivery On-Demand Live Webcasting CD-ROM, DVD

Network User connectivity Firewalls, multicast enabled routers

Other Password restrictions E-Commerce Media reports on viewer usage

Page 8: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

On-Demand content and live broadcasts

Streams on demand File-based Streaming Available to users at any time, and are sent on

demand.

Live Streaming Live broadcast event Encoder…

Page 9: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Options

Encoding Choosing a format

Real Media Windows Media Quicktime

Determine a window size

(Width x Height in pixels) 160x120 240x180 320x240 Even larger

Page 10: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Options

Encoding Bitrate selection

Single rate - 28k, 56k, 120k, 200k, 400k One stream per bitrate One encoded file for each user’s connect speed One URL for each connect speed

Multirate – (28k-56k-200k) Real - SureStream Windows - Intelligent Stream Quicktime - Alternate Movies One encoded file can reach multiple connect speeds Server finds optimum connect speed and adjusts as network

bandwidth usage changes Only one url needed for all connect speeds Larger file size for archive media

Page 11: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Options

Authoring Include powerpoint slides sync’d to video Insert graphics, images, logos Add URL links to other sites or content Create a URL to play only parts of the media Create a playlist within one URL to stream multiple

clips or media files Set player commands, end-user controls Pop-up or embedded player

Page 12: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Options

Indexing Assign keyframes to your content media Allows you to create smaller segments of your media

and store them as clips Add keywords to clips for users to search your

media from a website Convert speech, closed captioning and ppt slides to

text for searching Save clips in a playlist and share them with other

users

Page 13: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Streaming Media Options

Webcasting Live presentations over the internet One multicast stream to many users Include powerpoint or other rich media

Hosting On demand playback of archived media Multiple streaming server platforms Unlimited streams Low storage costs No impact on your own network No hardware resources to maintain

Page 14: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Combining Media Limitations

Web browsers are not designed to fully support multimedia features

Limited coordination of media elements

Page 15: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

The Problem

Lots of Bits Images, audio and video are beyond Internet design specs Results in space/ time constraints at:

the server the network( s) the client

Not All Bits are Equally Important Time between samples often more important than bits in sample, for example lip synchronization (but not always...)

Content may be Distributed Across Network Need to synchronize presentation

Objectives Add synchronization to the Web Allow interoperability Use declarative format, preferably text — thus XML

Page 16: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

Solution

Use of a single timeline for all media

Creation of time-based multimedia delivery over the web

Synchronization

Coordination

Page 17: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

What Is SMIL?

SMIL stands for Synchronized Multimedia Integration Language

SMIL is pronounced "smile"

SMIL is a language for describing audiovisual presentations

SMIL is easy to learn and understand

SMIL is an HTML-like language

SMIL is written in XML

SMIL presentations can be written using a text-editor

SMIL is a W3C standard SMIL 2.0 August 2001 http://www.w3.org/TR/smil20/

Page 18: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

What Is SMIL?

Page 19: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

A Simplified SMIL Example

<smil>

<body>

<seq repeatCount="indefinite">

<img src="image1.jpg" dur="3s" />

<img src="image2.jpg" dur="3s" />

</seq>

</body>

</smil>

Page 20: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

What Can SMIL Do?

SMIL can be used to create Internet or Intranet presentations

SMIL can be used to create slide show presentations

SMIL has been described as the Internet answer to PowerPoint

SMIL presentations can display multiple file types (text, video, audio...)

SMIL presentations can display multiple files at the same time

SMIL presentations can display files from multiple web servers

SMIL presentations can contain links to other SMIL presentations

SMIL presentations can contain control buttons (stop, start, next, ...)

SMIL has functions for defining sequences and duration of elements

SMIL has functions for defining position and visibility of elements

Page 21: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL Files

A SMIL file contains all the information necessary to describe a multimedia presentation

SMIL files are stored with the extension *.smil

A SMIL file contains the following: The layout of the presentation The timeline of the presentation The source of all multimedia elements

Page 22: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

How to Play a SMIL File?

You will need a SMIL player. Different SMIL players can be found RealOne Platform by RealNetworks has full support

for SMIL 2.0 SMIL Player by InterObject supports the SMIL 2.0

Basic Profile

With Internet Explorer 5.5 or later, SMIL elements can be inserted into HTML files

This way any SMIL presentation can run over the Internet as standard HTML files

Page 23: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL in HTML

Adding References Adding a "time" namespace definition to the <html> tag Adding an <?import> element to import the "time" namespace Adding a <style> element to define the class "time"

<html xmlns:time="urn:schemas-microsoft-com:time"> <head> <?import namespace="time" implementation="#default#time2"> <style>.time {behavior: url(#default#time2)}</style> </head><body> <time:seq repeatCount="indefinite"> <img class="time" src="image1.jpg" dur="3s" /> <img class="time" src="image2.jpg" dur="3s" /> </time:seq> </body> </html>

Page 24: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL Timing

time formats: hh:mm:ss.f number [h|min|s|ms] wallclock (YYY-MM-DDThh:mm:ss+zone)

Duration The duration (dur="5s") attribute

When To Start? The begin (begin="2s") attribute

Page 25: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL Sequence

<seq> - the most common SMIL element - defines a sequence

The <seq> element can have a number of attributes: begin, dur, repeatCount

<html xmlns:t="urn:schemas-microsoft-com:time"> <head> <?import namespace="t" implementation="#default#time2"> <style>.t {behavior: url(#default#time2)}</style> </head> <body><t:seq repeatCount="indefinite"> <h2 class="t" dur="1s"> I will display for one second</h2> <h2 class="t" dur="2s"> I will display for two seconds</h2> <h2 class="t" dur="3s"> I will display for three seconds</h2> </t:seq></body> </html>

Page 26: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL in Parallel

Objects inside the <par> element will be played at the same time Attributes: begin, dur, endsync= "first"|"last"|id(clip), repeatCount

<html xmlns:t="urn:schemas-microsoft-com:time"> <head> <?import namespace="t" implementation="#default#time2"> <style>.t {behavior: url(#default#time2)}</style> </head> <body><par> <t:audio src="liar.wav" repeatCount="indefinite" type="wav" /> <t:seq repeatCount="indefinite"> <h2 class="t" dur="1s"> I will display for one second</h2> <h2 class="t" dur="2s"> I will display for two seconds</h2> </t:seq></par></body></html>

Page 27: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL Transitions

IE 6 supports transitions based on the SMIL 2.0. Transitions are implemented with the element <transitionfilter> Attributes: type, begin, mode, from, to

Transition Filters fade, barnDoorWipe, barWipe, clockWipe, ellipseWipe,

fanWipe, irisWipe, pushWipe, slideWipe, snakeWipe, spiralWipe, starWipe

<t:transitionfilter targetelement="keyb" type="clockWipe" begin="keyb.begin" dur="2s" />

<img id="keyb" class="t" src="pic_keyb.jpg" dur="4s" width="128" height="107" />

Page 28: Media Streaming 12. What is Streaming Media? The delivery of audio/video/data between a server and a client (user), as a continuous digital stream Eliminates

SMIL Media Elements

<animation> <audio> <brush> <img> <param> <ref> <text> <textstream> <video>

Attributes: erase src type

<html xmlns:t="urn:schemas-microsoft-com:time"> <head> <?import namespace="t" implementation="#default#time2"> </head> <body><t:video src="http://www.ananova.com/about/vap_windows_check.wmv" repeatCount="indefinite" type="wmv" /></body> </html>