Streaming Multimedia

What is streaming?

Streaming media consists of sound and video, continuously “streamed” over the Internet

Streaming media (continued) Streaming media may be either video or audio, or

most commonly a combination of both. There are two categories of streaming, pseudo

and genuine streaming Pseudo streaming allows for immediate playback

as the file is downloaded whilst it is playing. Pseudo streaming uses pre-compressed data

Genuine streaming requires a specialised server and compresses the data on-the-fly, delivering content in an efficient format

The Principle of StreamingThe Principle of Streaming

(A snapshot in time)

Limitations on Streaming types Because video and audio data can be quite large,

compression is an integral part of streaming Pseudo streaming uses pre-compressed files and

only allows users to view media sequentially; you cannot skip to a set point in the stream

Genuine streaming allows a user to navigate to any point in the stream, but requires a dedicated server to do this. Genuine streaming files must be prepared specially for delivery

What’s going on behind the scenes on the servers?

Formats of Streaming

There are many formats of streaming available. Some of the more common formats are: RealPlayer Windows Media Player Quicktime Flash

What do the different formats do? Each format uses a different algorithm for

compressing and embedding the streaming data Different manufacturers place emphasis on

different aspects: video, sound, speed, bandwidth Because of the competitiveness of the different

manufacturers, each format represents a different means of achieving effective multimedia streaming

Different formats (continued) Common to virtually all formats is the MPEG

compression algorithm MPEG (Moving Picture Experts Group) develops

standards for the compression of digital video and audio

The actual compression is often referred to as a codec (coder/decoder)

Common MPEG standards deliver video at up to 8Mbps and audio at up to 96kbps

Why use streaming? Streaming allows for the delivery of high-impact,

engaging and often interactive content Streaming is typically very flexible and can be

distributed widely in a variety of formats Standard video and audio content is too large to

deliver via traditional formats. Streaming formats offer incredible compression and very effective delivery.

When to use streamingMultimedia content in any fashion is a two edged sword. It can

quite literally make or break a website

Users of a website must be able to efficiently and effectively navigate a site. Use of extraneous multimedia can be detrimental.

Not all users have access to high-speed internet connections. Multimedia can very quickly chew up a users available bandwidth, frustrating them if they cannot see multimedia as the author intended.

When to use streaming (continued)

With correct application, relevance and attention to issues such as performance, multimedia can be used to enhance any website.

For example: Multimedia streaming can be used as a self-serve sales tool. Instead of a customer waiting to receive literature of a product, they can view a video clip advertisement.

Considerations for streaming Bandwidth, bandwidth, bandwidth! Multimedia streaming in almost any format will

take up a significant portion of a user’s available bandwidth.

Some players will wait until a buffer of data is received before playback commences. This can result in a constant stop-start effect in the stream. This can be very annoying!

Adding streaming to your website Streaming can be inserted into your

website using either an Anchor tag, or using an Embed tag

<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" codebase="http://download.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=6,0,29,0" width="300" height="55" vspace="20" align="middle">

<param name="movie" value="../images/flickerboardnosound.swf">

<param name="quality" value="high">

<param name="LOOP" value="false">

<embed src="../images/flickerboardnosound.swf" width="300" height="55" vspace="20" loop="false" align="middle" quality="high" pluginspage="http://www.macromedia.com/go/getflashplayer" type="application/x-shockwave- flash"></embed>

</object>

Decision: Pseudo or genuine streaming?

You will need to decide on the best content delivery system.

Pseudo streaming will require sufficient bandwidth from the hosting server to deliver content

Genuine streaming will calculate the optimum bandwidth delivery to the client.

Don’t forget to test, test, test… Check the delivery of your content over a variety

of connection speeds and conditions; remember your target audience will judge the value of the streaming on it’s performance as much as anything else!

Make sure that you are delivering a common format. Obscure formats won’t win you any friends.

Consider whether the target audience will need to download new codecs to see the stream

Other directionsStreaming is not just limited to delivering video and audio over

the Internet. New developments include multi-casting, pod-casting and live streams.

Streaming is constantly changing, and in an ever-competitive world, the technology is being driven to deliver more and more.

Always remember, that while technology changes, your multimedia must still be relevant and efficient for it to work.

Live Streaming: What’s happening behind the scenes?

And now…

Vividas delivers broadcast quality video and audio real-time without the need for end-user software or players.

Explore some of the videos on showcase at the following site:

http://www.vividas.com

Some final considerations Legal issues are very important to consider when

streaming Make sure that you have the permission of a

copyright owner before streaming someone else’s content

Don’t forget to protect your own work See a legal professional for the best ways to

protect yourself and your multimedia work

StreamingReferences How Streaming Video and Audio Work

http://computer.howstuffworks.com/streaming-video-and-audio.htm Embedding Streaming Video Files

http://www.free-video-hosting.net/embed.php

Acknowledgements

This lecture was further developed from previous lectures by Sean Kelleher and Peter Somerville