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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.
1. Introduction1. Introduction
4
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.
1. Introduction1. Introduction
5
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:
1. Introduction1. Introduction
6
Quality of Streaming Video
High Quality
2.1MbpsADSL
340Kbps
ADSL150Kbps
Dial-up38Kbps
Original30Mbps
1. Introduction1. Introduction
7
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
1. Introduction1. Introduction
8
The Big Picture
2. What is Available?2. What is Available?
9
• 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…
2. What is Available?2. What is Available?
10
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.
2. What is Available?2. What is Available?
11
• Great potential with current BLU initiatives at UH:– Wireless campus– Mobile computing– Video streamed to Pocket PC devices
Will it work with UH network?
2. What is Available?2. What is Available?
12
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
2. What is Available?2. What is Available?
13
Example – Laboratory Work
2. What is Available?2. What is Available?
16
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.
2. What is Available?2. What is Available?
17
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:
2. What is Available?2. What is Available?
18
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
2. What is Available?2. What is Available?
19
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
Upload video file to media server and publish media links to the web / StudyNet.
Convert existing file
Step 1Step 1 Step 2Step 2
Upload video file to media server and publish media links to the web / StudyNet.
Windows Movie Maker Internet Explorer
Internet ExplorerWindows Media Encoder2. What is Available?2. What is Available?
20
Screen Captures
Step 1Step 1
Capture entire screen, window or an area
Step 2Step 2
Upload video file to media server and publish media links to the web / StudyNet.
Internet ExplorerWMedia Encoder
2. What is Available?2. What is Available?
21
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
2. What is Available?2. What is Available?
22
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
Number of connections
Avg
Ban
dwid
th Action On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast
52Kbps Streams
01000020000300004000050000600007000080000
1 10 500 600 1000 1600
Number of connections
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
Number of connections
Avg
Ban
dwid
thAction On-demandNews On-demandCartoon On-demandAction UnicastNews UnicastCartoon Unicast
3. Widescale Broadcast and Delivery3. Widescale Broadcast and Delivery
23
Results – Single Switch539Kbps Streams
0100002000030000400005000060000700008000090000
1 10 40 80 120
150
160
180 185
Number of connections
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
Number of connections
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
Number of connections
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)
3. Widescale Broadcast and Delivery3. Widescale Broadcast and Delivery
24
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(NormalUnicast)
273kbps(Normal
On-demand)
273bps (LBUnicast)
273kbps(LB On-demand)
Different Streams used
Num
ber o
f Con
nect
ions
Action ClipMax NumberofConnections
Normal Configuration vs. Load-Balancing
0500
100015002000250030003500
52kbps(NormalUnicast)
52kbps(Normal On-
demand)
52kbps (LBUnicast)
52kbps (LBOn-demand)
Different Streams used
Num
ber o
f con
nect
ions
Action ClipMax NumberofConnections
Normal Configuration vs. Load-Balancing
0100020003000400050006000
24kbps(NormalUnicast)
24kbps(Normal On-
demand)
24kbps (LBUnicast)
24kbps (LBOn-demand)
Different Streams used
Num
ber o
f Con
nect
ions
Action ClipMax NumberofConnections
3. Widescale Broadcast and Delivery3. Widescale Broadcast and Delivery
25
Survey Results - Workshop
• What has been your past experience in audio/video streaming over the network?
4. Survey Results4. Survey Results
26
Survey Results - Workshop
• On the scale of 1 to 5, please state whether or not you agree to the following:
4. Survey Results4. Survey Results
27
Survey Results - Workshop
• What is the potential of audio/video streaming over the network?
4. Survey Results4. Survey Results
28
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
4. Survey Results4. Survey Results
29
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
4. Survey Results4. Survey Results
30
Survey Results
• How often on average do you loan DVDs from the LRC
4. Survey Results4. Survey Results
31
Survey Results
• How often do you think you would use a video library such as this if one were ever to be implemented?
4. Survey Results4. Survey Results
32
Survey Results
• Where would you be most likely to use a video library such as this?
4. Survey Results4. Survey Results
33
Survey Results
• Do you believe a video library where you could access lecture content from home is a better idea than loaning DVDs?
4. Survey Results4. Survey Results
34
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?
4. Survey Results4. Survey Results
35
Survey Results
• Which part of the video library do you think you would make most use of?
4. Survey Results4. Survey Results
36
Survey Results
• Is there anything else you would like to say about the video library?
4. Survey Results4. Survey Results
37
Discussion
5. Discussions5. Discussions