The Effectiveness of Audio/Video Streaming at UH in Support ...

Johann SiauSchool of Electronic, Communication and Electrical Engineering

University of Hertfordshire

The Effectiveness of Audio/Video Streaming at UH in Support of Learning and Teaching Activities

2

TOPICS

1. Introduction1. Introduction

2. What is Available?2. What is Available?

3. Widescale Broadcast and Delivery3. Widescale Broadcast and Delivery

4. Survey Results4. Survey Results

5. Discussions5. Discussions

3

Overview

• The author recently ran a one-day workshop to instruct participants how using technology such as video streaming could allow them tolink up with StudyNet and use fast-moving video and live broadcast in support of their teaching material.

• Participants were also shown how existing VHS, AVI/MPG videos could be converted and streamed and integrated within their websites so that the best possible video quality could be achieved.

• The facility is also being used by a number of final year project students in support of their project work and in other modules supporting large cohorts.

• The presentation aims to address issues such as:– bandwidth usage,– application availability,– server clusters/load balancing,– methods of integrating these technologies into the existing network

infrastructure to enhance learning and teaching experience,– survey results.


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What is Streaming Media?

• Streaming media allows each client to render content as it is being received over the network without downloading the content first.

• Streaming greatly reduces the wait time and storage requirements on the client. It also permits presentations of unlimited length, as well as live broadcasts.


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Bandwidth Requirements

FORMAT PIXELS BIT-RATE FILE SIZE Dial-up56Kbps

ADSL 512Kbps

Wireless 11Mbps

~ 1 hr ~ 3 min

~ 11 sec

~ 2 sec

~ 0.8 sec

~ 0.2 sec

~ 4 min

~ 40 sec

~ 18 sec

~ 5 sec

~ 9 hrs

~ 38 min

~ 6 min

~ 3 min

~ 44 sec

228MBytes

15.74MBytes

2.62MBytes

1.16MBytes

305KBytes

30Mbps

2.1Mbps

340Kbps

150Kbps

38Kbps

LAN 100Mbps

DV-AVI 720 x 576 ~ 18 sec

~ 1.3 sec

~ 0.5 sec

~ 0.1 sec

~ 0.02 sec

Local Playback 720 x 576

Broadband Higher 320 x 240

Broadband Lower 320 x 240

Dial-up 56Kbps 160 x 120

FORMAT BIT-RATE 10Mbps (SWITCH) 100Mbps (SWITCH) 1Gbps (SWITCH)Local Playback 2.1Mbps 4

29

66

263

400

Broadband Higher 340Kbps

40

290

660

2900

Broadband Lower 150Kbps 6600

Dial-up 56Kbps 38Kbps 2630 26300

Typical download times:

Theoretical Maximum No. of Users Supported per server:


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Quality of Streaming Video

High Quality

2.1MbpsADSL

340Kbps

ADSL150Kbps

Dial-up38Kbps

Original30Mbps


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Advantages of A/V Streaming

• Contents are streamed to each user• Users receives the best possible video

quality depending on their connection speed

• Live broadcast is now possible• Protection of content• Users can control playback (on-demand)• Minimises the use of network bandwidth


8

The Big Picture


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• StudyNet / Existing MLE / Websites– Holds all the usual web based contents

• Lecture notes, etc. etc.• Embedded player.

– Links to media contents via ASX announcement files.

• MediaServer– Holds all media contents

• Video files *.wmv (encoded to ASF format)• Audio files *.wma (encoded to ASF format)• Playlists, station files

How it all comes together…


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Will it work with UH network?

• YES– several experimental results were obtained– just need to work out how best to manage

video contents• and most importantly…• … ASF streams can be carried over any

underlying network transmission protocol.


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• Great potential with current BLU initiatives at UH:– Wireless campus– Mobile computing– Video streamed to Pocket PC devices

Will it work with UH network?


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Example – Big Brother Lab

• Laboratory Session for 2nd year Students.

• Large cohort >170 students.

• Big-brother.

Windows Media Encoder

PCs in D410

Windows Media Tools Computer(s)

Microsoft Windows Media Player Cilents

Intranet PCs (eg. D410, D401, D405, any PCs within UH)

File Storage

1

2

3 45 5 5 6

WindowsMedia

UnicastService

WindowsMediaStationService

MediaServer.mmt.herts.ac.uk

Windows Media Server

Windows Media Tools can create .asf (.wmv/.wma) files.1

Windows Media Encoder (WME) can create .asf (.wmv/.wma) files.2

WME can deliver a live stream to a Windows Media Server (WMS) to be served as a unicast or multicast content.

3

WMS can use .asf (.wmv/.wma) files as a source for unicast or multicast content.

4

WMS can unicast content to a client.5

WMS can multicast content to a client.6


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Example – Laboratory Work


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StudyNet


http://www.studynet.herts.ac.uk/

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StudyNet


http://www.studynet.herts.ac.uk/

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Scenarios

• How can I make use of video streaming if?– I have existing VHS tapes or DV tapes or

Audio Books.– I have existing video files in different format

(eg. *.avi, *.mpg).– I want to capture what I do on screen.– I want to perform a webcast.


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Hardware / Software Requirements

ACQUISITION EDITING ENCODING PUBLISHING

• Use of DV Cameras, webcams.

• Video editing suite (eg. Movie Maker)

• Use of screen capture (Media Encoder)

• Video editing suite (eg. Movie Maker)

• Windows Media Encoder

• Text Editor• StudyNet• Internet

Explorer

• Hardware or software that can be used at different production stages:


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Step 1Step 1

Digitise analogue tapes by transferring to PC.

Existing Video – Tapes

Step 2Step 2

Import, Edit and Finalise video project

Step 3Step 3

Export/Save movie to streaming format

Step 4Step 4

Upload video file to media server and publish media links to the web / StudyNet.

Windows Movie Maker Internet Explorer


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Existing Video – different format

Step 1Step 1

Import, Edit and Finalise video project

Step 2Step 2

Export/Save movie to streaming format

Step 3Step 3


Convert existing file

Step 1Step 1 Step 2Step 2


Windows Movie Maker Internet Explorer

Internet ExplorerWindows Media Encoder2. What is Available?2. What is Available?

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Screen Captures

Step 1Step 1

Capture entire screen, window or an area

Step 2Step 2


Internet ExplorerWMedia Encoder


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Step 1Step 1

Prepare video file or video hardware

Step 2Step 2

Setup encoder to capture from input file/device and broadcast. Media server will pull data from the encoder.

Live Broadcast

Step 3Step 3

Announce and publish media links to web / StudyNet

Internet ExplorerWMedia Encoder


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Results - Normal Setup

539Kbps Streams

010000

2000030000

4000050000

6000070000

80000

1 10 40 80 120 150

Number of connections

Ave

rage

Ban

dwid

th Action On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast

273Kbps Streams

0100002000030000400005000060000700008000090000

1 10 100 200 250 300


Avg

Ban

dwid

th Action On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast

52Kbps Streams

01000020000300004000050000600007000080000

1 10 500 600 1000 1600


Avg

Ban

dwid

th

Action On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast

24Kbps Streams

0

10000

20000

30000

40000

50000

60000

70000

1 10 100 1000 2000 3500


Avg

Ban

dwid

thAction On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast


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Results – Single Switch539Kbps Streams

0100002000030000400005000060000700008000090000

1 10 40 80 120

150

160

180 185


Avg

Ban

dwid

th

Action On-demand(Single Switch)Action Unicast (SingleSwitch)Action On-demand(Normal Set-up)Action Unicast(Normal Set-up)

273Kbps Streams

0100002000030000400005000060000700008000090000

1 10 100 200 250 300 330 360


Avg

Ban

dwid

th

Action On-demand(Single Switch)Action Unicast (SingleSwitch)Action On-demand(Normal Set-up)Action Unicast (NormalSet-up)

52Kbps Streams

0100002000030000400005000060000700008000090000

1 10 100 500 1000 1600


Avg

Ban

dwid

th

Action On-demand(Single Switch)Action Unicast (SingleSwitch)Action On-demand(Normal Set-up)Action Unicast (NormalSet-up)

24Kbps Streams

0

20000

40000

60000

80000

100000

120000

1 10 100 1000 2000 3500

Number of connecions

Avg

Ban

dwid

thAction On-demand(Single Switch)Action Unicast(Single Switch)Action On-demand(Normal Set-up)Action Unicast(Normal Set-up)


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Results – Load BalancedNormal Configuration vs. Load-Balancing

050

100150200250300350

539kbps(NormalUnicast)

539kbps(Normal

On-demand)

539kbps(LB

Unicast)

539kbps(LB On-demand)

Different streams used

Num

ber o

f con

nect

ions

Action Clip MaxNumber ofConnections

Normal Configuration vs. Load-Balancing

0100200300400500600700


273kbps(Normal

On-demand)

273bps (LBUnicast)

273kbps(LB On-demand)

Different Streams used

Num

ber o

f Con

nect

ions

Action ClipMax NumberofConnections


0500

100015002000250030003500


52kbps(Normal On-

demand)

52kbps (LBUnicast)

52kbps (LBOn-demand)


Num

ber o

f con

nect

ions



0100020003000400050006000


24kbps(Normal On-

demand)

24kbps (LBUnicast)

24kbps (LBOn-demand)


Num

ber o

f Con

nect

ions



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Survey Results - Workshop

• What has been your past experience in audio/video streaming over the network?


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• On the scale of 1 to 5, please state whether or not you agree to the following:


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• What is the potential of audio/video streaming over the network?


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Survey Results – Initial Study

How Often do you use internet to aid your learning?

All the time

Quite a lotSometimesRarelyNever

0

5

10

15

20

25

How often Internet is used

Num

ber o

f Stu

dent

s

All the time

Quite a lot

Sometimes

Rarely

Never

Do you find online learning easier than general learning?

Yes

No

The same

Do You Currently use video libraries at the moment?

Yes

No

How useful would a video library be where you could get access of course related

information?

05

10152025

Very

Use

ful

Qui

teue

sful

Rea

sona

bly

Use

ful

Not

Ver

yU

sefu

l

Use

less

How useful?

Num

ber o

f stu

dent

s

Series1


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Survey Results – Initial Study

What type of information would you want in a video library?

Summary of Lectures

Related topics

Tutorials

Extra Course relatedmaterial

Other

Do you believe having access to video footage will help improve your performance

in the subject?

Yes NoNot Sure

How do you currently access the majority of information in your subject area?

Lectures

Studynet

Books

Videos/DVDs

Other

Do you believe a video library will encourage students to spend more time studying?

YesNo Not Sure


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Survey Results

• How often on average do you loan DVDs from the LRC


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Survey Results

• How often do you think you would use a video library such as this if one were ever to be implemented?


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Survey Results

• Where would you be most likely to use a video library such as this?


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Survey Results

• Do you believe a video library where you could access lecture content from home is a better idea than loaning DVDs?


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Survey Results

• How would you rate the quality of the videos on the video library?

• How would you rate the audio quality on this video library?


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Survey Results

• Which part of the video library do you think you would make most use of?


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Survey Results

• Is there anything else you would like to say about the video library?


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Discussion

5. Discussions5. Discussions

The Effectiveness of Audio/Video Streaming at UH in Support ...

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