Design and Testing of On-Demand Distributed Content Models for

Transcription

Mat Thomas
S75245/BAFM1107
RA/MM/FM 303: Research Project
Design and Testing of On-Demand Distributed Content Models for Distribution of High
Definition Media Over IP Networks
Submitted in Partial Fulfilment of the Bachelor of Arts (Hons) Film Making
Student Name: Mathew Aron Thomas
Student Number: S75245
Course code: BAFM1107
Due Date: 16th January 2009
WORD COUNT: 13,861(body)/16,805(body+ref)
Module Lecturer: Hardie Tucker
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Table of Contents
Summary
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Chapter 1
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1.1 Introduction
1.2 Purpose Statement 1.3 Outline of the Problem
Chapter 2
2.1 Hypothesis Statement 2.2 Definition of Terms
2.3 Scope of Research
2.4 Research Questions
2.5 Literature Reviews
2.5.1 Literature Review 1
Chapter 3
3.0 Overview
3.1 Research Family 3.2 Research Approach
3.3 Data Collection Methods
3.3.1 Questionnaire
3.3.2 Experimentation
3.4 Ethical Issues
3.5 Data Collection Summary
Chapter 4
4.1 Project Schedule
4.2 Resources
4.2.1 Hardware
4.2.2 Software
4.2.3 Selection Algorithm
4.2.4 Financial
4.2.4 Human
Chapter 5
5.1 Overview
5.2 Results
5.2.1 Gender of Respondents
5.2.2 Location of Respondents
5.2.3 Amount of movies watched (Hours per week)
5.2.4 Viewing Method
5.2.5 Amount willing to pay 5.2.6 Own an HDTV
5.2.7 Own HDTV Equipment
5.2.8 Amount of HD Watched (per week)
5.2.9 Amount Willing to Pay if no HD Viewed
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5.3 Project Activity
5.3.1 Pre-Buffer Data-Flow
5.3.2 Results of the Tests
5.3.3 Summary of Results
5.3.4 Final Test 5.4 Problems/Limitations of the system
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5.4.1 Power Usage
5.4.2 Internet Connection Usage
5.4.3 Fast-forwarding
5.4.4 Licensing
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5.5 Potential Benefits of the System
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5.5.1 Advertising
5.5.2 Content Rights
5.5.3 Indie Producers
5.5.4 Expandability
5.5.5 Data Amounts
Chapter 6
6.1 Conclusions
6.2 Recommendations
Chapter 7
7.1 Endnotes
7.2 References
7.3 Appendices
7.3.1 Scan from “HDTV for Dummies” page 86
7.3.2 SD/HD Resolution Comparison Table
7.3.3 Course Flowchart
7.3.4 Example Questionnaire
7.3.5 Project Schedule
7.3.6 Hardware Testing
7.3.7.1 Server - Installing Windows XP
7.3.7.2 Server - Network Speed
7.3.7.3 Server - Network Analyser
7.3.7.4 Server Configuration
7.3.7.5 Server - Splitting of Media File
7.3.8.1 Client - Network Analyser
7.3.8.2 Client - Simulating ADSL Bandwidth
7.3.9.1 Viewer - Connection to Server
7.3.9.2 Viewer - Method
7.3.10 Viewing Bias Code
7.3.11.1 Original Virtual Data Flow Diagram
7.3.11.2 Refined Virtual Data Flow Diagram
7.3.12.1 Questionnaire Results
7.3.12.2 Questionnaire Analysis
7.3.13 Data Flow Decisions
7.3.14 Initial Testing Results
7.3.15 Penultimate Test Results
7.3.16 Final Test Results
7.3.17 Spec Sheet of Proposed Hardware (from module 301: Business Plan)
7.3.18 Specialised Application (from module 302: Specialised Application)
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Summary
In my opinion, high-definition media within the industry is not growing as fast as it could. A possible
reason for this is that peoples expectations of content have changed over the years. I firmly believe
that people want to watch what they want when they want, an opposite to the current TV broadcast
model.
A problem associated with content of all kinds, not just high definition, is that of distribution.
Originally aided by the automobile and transport links, the current problem is that due to the
widespread physical location and increase in the number of viewers this solution is no longer
viable.
This has been partially solved in cinemas by using satellites and hard-drives containing the films
data. In my opinion home entertainment has been “left behind” in this field, especially when dealing
with large amounts of data, such as high definition audio and video. My theory is that if people had
a choice of high definition films in their home to view when they wanted, they would.
My research aims to develop a system capable of using current technologies to allow the above to
happen. It will work by exploiting the “down-time” of the the person (while they are at work/asleep)
to its advantage. Based on this and further research into the technological methods I could
potentially use, a system was developed containing a total of 12 clients (viewers) and 1 server.
The evaluation of the project was one simple criteria: to be able to flawlessly playback HD content
without any physical media changing hands, using current technologies. I would suggest that any
future researchers attempt to create a wider test-bed in order to gain more useful feedback.
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Chapter 1
1.1 Introduction
The problem of distributing media to an audience is one as old as media itself. What use is media
without a method of delivering it to an audience? Traditional means of delivery use physical media
such as vinyl records, audio tape and CDʼs. If we look at the film counterparts to these we can also
include VHS, Laserdisc, VCD, DVD and more recently HD-DVD and Blu-Ray. Alternative nonphysical methods of delivery include AM/FM radio and broadcast (UHF/VHF) TV. The non-physical
methods of delivering media, more specifically “high definition” films and TV shows, are what I am
concerned with.
To take this a step further and narrow my scope of research, I will be looking at IP based
distribution methods. This broadly means “the internet”, however it is important to identify the
difference between developing for the internet, and developing for an IP based system. If we
develop for the internet then we are constricted by certain restrictions of the internet and
consequently have to develop to these standards. If we develop for IP based systems we can
design the system to work with a multitude of standards as well as potential for operating the
system over the internet.
Based on previous work with networking, I will not attempt to run any tests on a connection which
has less downstream bandwidth than 512kbps, or half a megabit. This is because although many
ISPʼs will class it as “broadband”, 512kbps is not a sufficient amount of bandwidth to provide
accurate results as the overheads involved with IP networking limit the connection to around
460kbps. Broadband is a relative term, and although many people understand a 512kbps
connection to be broadband, the FCC (America) regard anything over 768kbps to be “broadband” 1.
1.2 Purpose Statement
My project and associated research has lead me towards my intended destination within the
industry. I am interested in the field of media distribution and more specifically using computer
based systems to improve the speed, quality and reliability of distribution. My project is to research
and ultimately develop a system which allows for on-demand viewing of high-definition content.
The benefit of researching this topic is that it is directly related to my project. The industry is
changing rapidly and to create a system which utilises the full potential of current technologies, it is
important to know what the current systems are, what they can do and most importantly what they
cannot.
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1.3 Outline of the Problem
In my own opinion, the way in which audiences view films and TV shows is constantly changing. To
capitalise on both new and existing audiences, distributors need to be at the forefront of
technology. In the past it seems that movie studios have generally resisted new media formats and
distribution methods.2
According to the article, it seems that there are three main reasons why studios generally resist
adopting new distribution methods. The primary reason given by the article is the issue of piracy;
studios are extremely concerned with protecting their investments. A secondary reason is that of
resistance by the general public; either for reasons of cost or lack of compatibility with their existing
equipment. The final reason is that if customers can watch high-quality movies in their home, what
would happen to the business of cinema?
A number of formats have come and gone over the years, with varying success, and I will attempt
to present in greater detail the reasons for success/failure. This will involve amounts of research
from the perspectives of both producers and consumers. “Format wars”, or situations in time where
two or more comparable methods of distribution have entered the marketplace at roughly the same
time, are not a new phenomenon. An early example of this can be seen in the late 1880s with
regards to distribution of electricity, and whether to use AC (alternating current) or DC (direct
current).3
From my own observations of the distribution of content, it appears that in the majority of countries,
excluding the USA and Japan, there is currently no legal model for viewing HD content without
physical media (such as Blu-Ray/HD-DVD). The problem with this is that younger generations want
to view media how they want, when they want and where they want. From my own research of
asking people in my age group (18-25), apparently current solutions are well below that of what
current technology is able to deliver. Furthermore it seems that much of this sample are switching
to illegal methods of obtaining media for the simple reason that there are little alternatives which
suit their desires.4
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Chapter 2
2.1 Hypothesis Statement
Design and Testing of On-Demand Distributed Content Models for Distribution of High Definition
Media Over IP Networks.
2.2 Definition of Terms
Test: A scientific approach will be used based on my previous learning's.
The main technical approach to testing throughout this project is that of “white
box testing”5. I am able to use this method of testing as I wrote all of the code
which I will be testing. This method is by far the most efficient as the tester has
the ability to change nearly every variable, however it is not commonly used as it
requires the tester to have full knowledge of the system being tested.
On-Demand:
a viewer ʻpullsʼ, or requests media from a content server
Model:
“a representation, generally in miniature, to show the construction of something” 6
High-Definition: “at least 720 horizontal lines of resolution with progressive scan” 7
IP:
“the main network layer (3) for the TCP/IP protocol suite” 8 or one of the most
common network protocols, as used within the internet, but not exclusively.
Network:
“a system of interconnected electronic components”9
2.3 Scope of Research
My research towards this project is primarily focussed on experimental testing of various distribution
methods, and their related performances, advantages and practicalities. I will have to initially decide
on which methods I will test, as there are potentially thousands to choose from. It is important to note
that I will be testing the technical and practical aspects of the systems, with little focus on the
aesthetics of each method of distribution. I will not be concerned with methods of limiting piracy, I will
however allow for the system to be compatible with common types of rights management.
I have identified the following as being topics which are out of the scope of this research; the content
which I will be transferring is essentially irrelevant and will not be judged. Another aspect of the
research/project which I will not be concerned with is the usability of the software nor the set-up of
the systems. Although it is required for me to complete the project/research, I am focussing on the
transmission methods, and while interface is an obvious component of media distribution, I do not
have the time to design a GUI, furthermore a GUI for navigating on a TV could be a research project
in itself.
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2.4 Research Questions
Some questions which arise regarding my research are listed below:
1. What current alternative methods of delivery are available?
2. Which codecs should be used?
3. What is the current state of worldwide IP communications?
4. What devices will the media be playing on?
5. What do audiences want to watch?
6. What HD standard do audiences want?
7. How much would people use a service like this?
8. Why is there not a current solution to the problem identified above?
9. Has there been research in this specific field already?
10.Who would be interested in this research / project?
Some less relevant questions which still have a bearing on the project but are not critical to
success:
What legal problems are involved with this method of distribution?
How can we prevent / limit piracy?
Many of these questions lead to further questions with little potential for a definite answer. This is
not necessarily a problem, just something to be aware of when presenting the findings later on in
this document.
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2.5 Literature Reviews
HDTV for Dummies, Briere, Danny & Hurley, Pat, Wiley Publishing, 2007
The authors of this book have both got a great deal of credibility within the media industry, more
specifically the technology side. Danny Briere is “one of the original modern-day telecom
strategists, having advised carriers, vendors, regulators, start-ups, and governments for more than
20 years” 10. The source also goes on to say that “Briere is recognised as one of the most creative
and innovative telecom strategists in the industry today.”11
The source for the aforementioned quotes are from a company called “TeleChoice”, who define
themselves as “the leading strategic catalyst for the telecom industry”12. This source indicates that
the author is the CEO of the company, so we have to consider this source potentially heavily
biased towards painting the author in a positive light.
For the second author, Pat Hurley, it seems that he has a very detailed knowledge of logic, which
forms the basis of all computing technologies 13. He also has written or co-written many other books
of the “dummies” series, focussing on media and its associated technologies.
The authors make no exaggeration as to the complexity of the content within the book. It is
designed for beginners to understand the terms and related technologies for HDTV. The reason I
believe this book will prove useful to me, is that quick referencing of terms that I donʼt understand
is completely necessary within this contemporary, still evolving technology.
After reading the book further, I realised that it wasnʼt lacking in detail as much as I thought it was.
In certain areas the authors describe in immense detail certain aspects of this technology, for
example “Table 6.1” 14 (Appendix 7.3.1), which explains the bandwidths, modulation types and bit
rates of some popular distribution mediums. Furthermore, detailed information like this are always
externally referenced. This allows me to follow the reference for possibly even more specific
information from the same original source.
The book also includes some topics I will most definitely not be requiring; namely “Mounting your
HDTV” and “Places to buy an HDTV”. These sections are designed for consumers, and although
they both heavily reference external sources, they are of no interest to my field of research.
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(The Technology of) Video & Audio Streaming, Austerberry, David, Focal Press, 2005
This book has been praised by the European Broadcasting Union and they said “for broadcasters...
involved in media delivery across the web, this book could be a very useful first step in
understanding the basics of streaming technologies”. The author has worked in the industry of media
communications for over 30 years, for 10 of those he was a project engineer for the BBC(UK).15
The content of the book is highly detailed, focussing on the more technical aspects of media
streaming. It covers everything from the history of print and media development, aspects of
convergence within the industry and IP networks, right up to encoding methods, webcasting and
DRM (digital rights management).
The book provides excellent referencing, along with a clear and concise glossary and abbreviations
section. This part of the book is useful for quick look-ups of terms, while the previous 300 pages are
designed for advanced technical reading. I believe there would be many literary prerequisites for this
content, however from reading sections I have ascertained that I have enough knowledge in this field
for the book to be useful for my research.
Each section has its own summary, complete with further reading sources. The book has sections
which are not as relevant to my research as others. These include sections detailing content creation
methods for particular applications, such as webcasting and audio. Although these sections will not
be called upon, there is still useful information held within them, for example frequency responses of
average consumer sound systems. Information such as this could become useful when testing in the
future.
Sections I am particularly interested in, which will form much of my research, include encoding
techniques, “Multicasting” to multiple devices using multiple encoding methods and finally rights
management. All the above sections are of interest to my research, since they make up around 70%
of my project.
The only disadvantage with this book, is that it was last revised in 2005, and it is now 2008. This
means that potentially 3 years worth of technical advances will not be included in this book. 3 years
in technological terms is roughly between double and triple the levels of technology within the
industry, if we follow Moores Law 16. Because of this I will need to try to find a newer revision of the
book, or consult external sources for further, more accurate and contemporary information.
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Film and Television Distribution and the Internet, Sparrow, Andrew, Gower Publishing, May 2007
This book covers primarily the laws / regulations and current trends concerning internet distribution
of film and TV media. The way in which the author presents this information is very clear and
simple. He has decided to group together associated laws and regulations, present them in their
entirety and then break them down into their key points. This approach to complicated law
breakdowns is welcome, as it allows any individual interested in this field to understand perhaps
the largest obstacle to the media industry and distribution.
The author himself is solicitor in the UK and his primary interest is in media distribution law. He
was acknowledged in 2004 as “one of the 100 individuals in the UK who have contributed most to
the development of the internet in the last 10 years” by the DTI17. The author provides plenty of
further reading in this field, however the majority of it is written by the author himself. This in turn
could provide a bias opinion on the various laws and regulations. There is, however, a large
selection of related material written by other authors.
Law is something which I have little knowledge about and after reading sections of the book, it
becomes apparent that it is an extremely important component of the industry. To research various
distribution methods and be able to work effectively within this field, a knowledge of any related
potential hinderances, such as The Data Protection Act of 199818, is crucial. I believe this book will
be one of the most helpful towards my research and project, as it is possibly the most important
aspect of the industry with regards to new distribution technologies.
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Chapter 3
3.0 Overview
One of the primary reasons for undertaking this research is that I personally feel that the
distribution models employed by the media industry are lagging behind what is technically
possible. I feel that the music industry realised this extremely late, only after services such as
Napster19 became mainstream. It is only recently that major record labels have adopted the
internet distribution model. This was hard-hitting for the industry as the majors had pretty much
missed an opportunity to increase publicity, revenue streams and audience in one go. I believe that
they were more concerned with trying to protect their (then) current models that were quickly
becoming outdated.
The only reason in my opinion that this has not really happened to the film industry yet is that the
technical conditions are only just now becoming aligned with viewers expectations. Put simply, a
128kbps MP3 audio file is around 3mb in data size, which is no more than 5 minutes downloading
time on even the slowest of internet connections. A feature length movie, on the other hand, even
when heavily compressed, is around 700mb. This in turn means potentially having to wait around
18 hours for the download to complete. People are generally quite impatient and if the process is
going to be as long as 18 hours for one movie then they will probably seek alternatives. This in my
opinion makes the entire industry complacent.
Based on the above opinions it is clear to see that it is simply a matter of time before the
technology “catches up” and the times taken are severely reduced and in turn peoples propensity
to obtain movies using whatever method increases. I also believe that there is another factor which
helps shift the “power” back to studios. The idea of “HD” content and the benefits associated with it
are major factors in customers purchasing habits. HD also means that the amount of data required
is increased significantly, at least 4 times that of “SD”20 (see appendix 7.3.2). This obviously means
that once again the movie industry is in a strategic position which the music industry can only
dream of.
Again, based on my own observation, the movie industry isnʼt capitalising on this potential market
for many reasons. The internet and IP systems are still essentially in their infancy and issues such
as piracy, guaranteed service levels, security and licences instantly arise as soon as you begin to
discuss this very issue with industry professionals. I believe, however, that these issues can be
resolved and it seems that more and more trust is being put into this field of the industry, but not at
a quick enough pace. I intend to focus my research on technical constraints and quality of service.
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A brief description of my background may help to understand my reasoning for undertaking this
project. I have always been interested in computers and more specifically data communications. I
previously attempted to undertake this very same research in the UK, at UMIST while I was
studying for a BSc in Computing Science. I felt that the course had modelled its educational
rationale on that of a “factory line”. It seemed that people were being taken in and as long as they
completed the expected work they would pass. I expected that creativity would be put behind
productivity as it was a BSc course at an antiquated UK institution, however I was shocked as to
how much; I proposed this very same research/project as my 3rd year project. I was surprised to
hear that no lecturer wanted to assist me, a requirement of the project. When I consulted my
personal tutor very little assistance was given other than “choose something simpler”.
The original reasoning for the main hypothesis of this paper was based on both personal
experience and observation of others. I noticed that people within my age group (younger people
even more so) would prefer to watch what they wanted and when they wanted. It seemed to me
that the old content distribution model of a TV broadcast system, where people watch what the
broadcast company wants them to, was being rejected by younger generations.
As soon as the technology and community is in place then we can see real-life examples of this,
one of the most successful is YouTube. YouTube is often seen as little or no threat to TV, however I
believe that the very fact that people are accessing content in a different manner to traditional
methods is enough reason to “listen” to the audience. Even with the (when compared to TV) poor
content and poor quality available on YouTube, people still want to view the content available. I
believe this is party due to a perceived choice of what to watch (it is possible to obtain a higher
ranking in YouTube search results by paying a fee therefor lessening the real choice).
One big downside from my experience of YouTube and similar “video streaming” websites is a
phenomenon called “buffering”. A buffer is supposed to allow for smooth, uninterrupted playback
no matter what connection you are using. This is wonderful in theory however in practice it doesnʼt
always work properly. This is something which I want to include into my project, or as I will refer to
it from now on “quality of service”. When I watch a movie, I want to watch it entirely uninterrupted
otherwise it detracts from the “flow” of the movie.
With all the above in mind, I wanted to try and look into the possibility of somehow merging the
community idea of YouTube with movies, while keeping up with current technologies and providing
flawless playback to appeal to the widest audience possible. A flowchart outlining this can be found
in section 7.3.3.
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3.1 Research Family
My research primarily contains quantitative data, as the project is an experiment and the results of
which will be in numerical format. There is, however, a limited amount of qualitative data to
process. This is because I have to analyse human responses to open ended questions about
viewing habits; when, what, why and how. I am able to make qualitative statements derived from
the qualitative data, however. The data is split around 80% quantitative and 20% qualitative.
I will be using a combination of experimentation, targeted questionnaire and a limited amount of
unstructured feedback. The primary method of data collection before I began the project was a
questionnaire, the results from the testing phase of the project were based on an experimentation
approach and finally feedback was sought from industry professionals, however a lot of it was
unstructured.
3.2 Research Approach
My research uses one main type of approach, the “experimentation” method. I have attempted to
investigate various methods of distribution by testing their performance using an array of
computers simulating demand. “Experimentation” is defined as “the process of testing a hypothesis
by collecting data under controlled, repeatable conditions”21. To effectively produce credible results
from an experiment I needed to be able control my testing and be able to repeat it. I achieved this
by running 4 computers continuously, one being a server for media (simulating the broadcast
company), and the other three running four “virtual machines” 22, giving a total of 12 clients
(simulating the viewers). The systems did not display the content, they just simulated the speed of
transfers which could be achieved over IP networks.
The reason for using virtual machines is twofold; it reduces total expenditure of the project by
limiting physical machines whilst allowing for relatively easy control of test conditions. By creating
one “image” of a system running under different conditions, it is extremely easy to replicate this on
multiple virtual machines, whilst still retaining individuality of each “client”.
If the research were to be conducted without thought for cost, then I could rent 13 additional ADSL
internet connections, and connect each system to the internet individually. This however would
cost somewhere around 26,000฿ (£380/$790) per month. My solution to this problem therefore is
that the clients ran on a LAN at 1000mbit/sec. The data rates of each client were “capped”, or
limited, to simulate real life conditions, depending on the test being run.
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I ran each test for one week to simulate a typical “weeks viewing” from a client. I aimed to run 8
different tests, modifying the following variables, narrowing their parameters later based on further
research: bandwidth available, containers/codecs used, distribution methods (server-client, peerpeer, etc.) and resolutions of audio/video. This gives a total of 2 months for the intended tests to
complete, however the actual time taken depended on the time taken to set-up the systems and
any problems I ran into.
3.3 Data Collection Methods
After consulting various sources regarding data collection methods I had decided to attempt to
triangulate data sources. According to the University of Bolton23 , triangulation is “a way of assuring
the validity of research results through the use of a variety of research methods and approaches. It
is a means of overcoming the weaknesses and biases which can arise from the use of only one of
the methods we have described, such as observation, questionnaires etc” 24
If we were to attempt to triangulate this statement in itself, I would draw on my personal learning's
from in class along with informal interviews with other researchers. In essence, the more data
sources you can acquire which either corroborate or contradict the other data sources, the better.
Based on the above, I decided to collect data from the following sources (and their types) and
further on I will attempt to triangulate specific data:
Questionnaire
Primary data
Experimentation
Primary data
Industry Professionals
Primary/Secondary data
Document Reviews Secondary data
Previous work
Combination of data types
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3.3.1 Questionnaire
To obtain information regarding viewing habits, I looked for studies already completed, as a sample
population available to me would have been far too small for the scope of this project. This was
accessed from government organisations from various countries 2526 . To further enhance the
credibility of this data, I sampled a population of TV viewers and provided them with a simple
questionnaire regarding their current viewing habits. I attempted to mirror the questions already
answered from external sources, to make the triangulation of data reliable.
Questions and potential answers I asked are as follows:
• Age
• Gender
• Location
• How often do you watch movies
• Less than 1 hour per week / between 1 hour and 5 hours per week etc.
• What method of viewing do you use mostly and why
• Cinema, TV, PC, Mobile Phone, PMP
• Do you own an HDTV (capable of displaying 720p material)
• Do you own any equipment which allows you to watch HD material
• Satellite, BluRay/HD-DVD, Media Centre, HD-DVR (HDD Based), PlayStation3™
• How often do you watch HD material?
• Less than 1 hour per week / between 1 hour and 5 hours per week etc.
• How much would you be willing to pay (per month) for unlimited HD content on demand?
• 0B-500฿, 501฿-1000฿, 1001฿ - 2000฿ etc.
My reasoning for producing a questionnaire as the one outlined above mainly came after
suggestion from Thames Valley University 27. They explained the key points to producing a
successful questionnaire; keep it short, use unambiguous questions, questions should only
address a single issue, to name but a few.
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I initially posted this onto a survey website with a low level of success. What I found was that I
received a massive amount of responses (over 300 submissions), however the results weren't
particularly useful. It became quite clear to me that people who took the survey already had a keen
interest in my field of interest; HD film and thus the results were atypical.
I believe the reason for this was that I posted the survey onto a popular forum for discussing
everything video related; doom9.org28. The results from the initial survey were extremely biased
towards “power-viewers”; people whose hobby is digital media. In turn it was very rare to see
answers from people who didnʼt have much interest outside of “power user” viewing habits.
Another point of note was that as the surveys were effectively anonymous, I donʼt believe that
many of the responses given were entirely accurate. From my own observation it seems like many
people on forums such as these (which otherwise provide invaluable information) tend to try and
out-do one another by way of exaggeration. For example for the question “ Do you own any
equipment which allows you to watch HD material?” the responses were nearly all “yes” (~98%).
This, in my opinion, is a combination of both bravado and my choice of sample population.
Considering the above issues, I decided to drastically change my method of both sampling and
questioning. I prepared an open ended questionnaire with the same questions (minus age/sex/
location questions) and sent it to people whom I actually know, friends and family. I also put a
statement at the beginning of the email explaining the point of the questionnaire and encouraged
people not to lie or exaggerate. My basis for doing this was that I already know roughly about
peoples viewing habits, as they are friends/family, and that a more personal questionnaire would
yield more accurate results. (original email available in appendix 7.3.4)
The questionnaire was emailed to 25 people, out of which I received 21 responses. I was
disappointed in both the number of available people and the response rate at first, after having
over 300 replies initially, however as soon as the data was inputted into a spreadsheet it became
apparent that quality of data is far more important than quantity of data. In retrospect I think that I
could have obtained a balance between quantity/quality by posting the questionnaire to my
Facebook page, by way of a mass message, however I believe that the results I obtained are
sufficient for my research as they match my expectations.
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3.3.2 Experimentation
I left all systems running 24 hours per day, for one week at a time. I varied usage time & content
accessed on each system (to simulate different customers). The systems each logged their
individual statistics, these include
• Average data rates achieved
• Time taken between the request of the media and the delivery of the media
• Whether viewing was interrupted and why
• Total bandwidth used
The results of these experiments are presented to me in their raw form, this being simply numbers
for the above test factors. The benefit of using logging software for this research is that I can
choose specifically what I want to analyse after the test have completed. For example the software
allows me to log everything related to the tests, and I can choose date ranges and types of data to
extract and analyse. Examples of data for the above tests will include numerical data presented in
a computing specific format; KB/s (kilobytes per second) for data rates, some exponential on bytes
for total bandwidth used and so forth. For more technical data such as MTU size (maximum
transmission unit) I required further research into ways to interpret the data.
To attach credibility to my results I ran multiple logging systems on each machine and compared
the results. My micro-hypothesis is that “every result from every machine should collaborate with
each other machine, allowing for a small margin of discrepancy”. I achieved this by running the
following logging systems:
• 1 system-wide logging software application running on
• server machine (total of 1)
• client machines (total of 3)
• virtual machines (total of 12)
• 1 application specific logging software (the application varied on each test)
• server machine (total of 1)
• virtual machines (total of 12)
• 1 overall logging utility from the network switching hub
The above systems provide one primary data collector per “virtual client”, one per “client machine”,
two from the server and one more from the switching hub. This in effect gives us 5 data sources,
one which is a base and 4 more from 3 different sources to collaborate with.
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These results will be used to compare the different methods applied to deduce a final system to
test further which will form the basis of my project. I need to be able to verify the results, which is
why I observed various systems at set intervals and logged the results manually. The problem with
this method of data collection is that if a system fails for any reason and there is no alert to this,
potentially an entire week of research will be wasted. This is why I included fail-safes into each
system; if a problem is detected, it is noted and the system is automatically restarted to minimise
downtime. However this potentially random downtime can add substance to the research if it is
managed effectively. This is because in a real life situation external factors will affect the results of
the system. For example if there were a power-cut to one of the systems, it will affect the
performance of other systems on the network. As long as these outages are logged and included
in the data breakdowns then the results will accurately represent the tests performed. Considering
the aforementioned data collection methods, my research will primarily be “desk” based, with very
little “field” research.
3.4 Ethical Issues
For my research there are very few ethical issues, however I had to obtain and transfer large
amounts of media data from different sources. As the media itself isnʼt being critiqued in this
research, there is no reason why it canʼt be a compilation of usable media from various open
source sources, such as “Mariposa HD”29, which is distributed under a “Creative Commons
License”. This particular source allows me to carry out all of my test conditions within the law,
however for the final tests I wish to use the movie “Pulp Fiction”30 as I will have to be watching it
about 4 times to analyse the “flawlessness” of the playback.
Another ethical issue is that of piracy; my systems must be able to handle the inclusion of
implementations of DRM (digital rights management) for it to remain a viable transmission method.
Above I mentioned that I would not be including any form of anti-piracy systems as it is outside the
scope of the research. To clarify this, the system can include DRM however for the purposes of the
following tests none was included.
Due to the way the algorithm (which selects potential films for the client) works, it becomes
apparent that people might have concerns with their privacy; what they are watching and the fact
that the system knows this. As with all interconnected systems which transfer any kind of personal
data, not only is it crucial that the data being sent is sent in a secure manner, but it is also wise to
design the system so that as little as possible information is sent to the server. For example,
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instead of sending the viewers information for the server to process we can instead send the entire
list of movies available to the client and process everything locally.
Probably the most important ethical issue to this project is that of energy saving. As the technique I
am using for distribution uses the electricity and internet connection of the client while they are
away (at work/sleeping etc.), many people might want to switch off the device to save energy. This
creates a problem as it is that specific time which allows the system to work effectively.
One final issue which I believe should be included in this section is that of my final test subject.
Once all of the initial tests had been completed and a working final model was produced, I decided
to test it in a more “real-life” situation, as previously mentioned. I used a HD version of the film
“Pulp Fiction” and attempted to watch it from start to finish without any problems. The ethical issue
arises because in Singapore this particular film is banned, and although no practical demonstration
of the model is required, this would have limited my options if I had chosen to do so.
3.5 Data Collection Summary
Question Collection Method
1. What current alternative methods of delivery are available?
Document Review
2. Which codecs should be used? Spec App
3. What is the current state of worldwide IP communications?
Industry Professional
4. What devices will the media be playing on?
Questionnaire
5. What do audiences want to watch?
Questionnaire
6. What HD standard do audiences want? Document Review
7. How much would people use a service like this?
Questionnaire
8. Why is there not a current solution to the problem identified above?
Industry Professional
9. Has there been research in this specific field already? Document Review
10. Who would be interested in this research / project?
Combination of sources
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Chapter 4
4.1 Project Schedule
I had a project schedule planned before I started the project as outlined in section 7.3.5. This
schedule varied a lot, mainly due to reasons of software mismatching, which are detailed in the
following section. As of writing I am around 3 weeks behind schedule, however I allowed for a
December presentation, which in reality doesnʼt occur until January, so although I am behind on
my schedule, I am on track with the course schedule.
Quite a few problems were encountered primarily with the software and accuracy of reporting test
results. These problems were quickly identified and rectified before they affected the schedule too
much.
4.2 Resources
This section details the resources needed in order for me to complete my project in its entirety. Due
to the nature of the project, the majority of resources will be weighted towards technical rather than
nontechnical. The divisions are outlined below:
4.2.1 Hardware
The research required a large amount of computer hardware. I already have access to this hardware
personally and I will be running four of the following systems, all of which are in my possession and
free to use as I wish. A photo of the hardware being set-up is available in section 7.3.6.
• Intel Pentium 4, 2.4ghz Processor31
• 1024mb DDR2 RAM
• 120gb SATA 7200RPM HDD
• 1000mbit Ethernet
• Systems are linked using an SMC 8 port 1000mbit Switch32
These systems are perfectly suited for my applications, as they will allow me to test what I plan to
without the need to buy any additional equipment. They were divided into four virtual machines all
using an equal share of the computers resources. This gives each virtual machine the following
specifications:
• 600mhz CPU usage
• 256mb RAM usage
• 30gb storage quota
• 250mbit network access
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The above shared resources are variables which I can alter depending on my needs after the initial
test run. They can also be dynamically altered whilst the tests are running, however I would like to
limit the number of variables because it would make analysis of the tests significantly more difficult,
except for storage space. This is because depending on the test situation, certain clients may
require more or less storage space depending on the extents of the test.
4.2.2 Software
The software I planned to use for both the research and project included the following.
• Virtual Machine - VMWare Workstation33
• OS - Microsoft Windows XP34
• FTP Client - FileZilla35
• FTP Server - FileZilla36
• BitTorrent Tracker - BitComet Tracker37
• BitTorrent Client - Azureus38
• Network Speed Limiter/Monitor - Net Peeker39
The “base” OS is a reduced version of Windows XP, using VMWare to run 4 virtual machines of
Windows XP. Only the functions needed for my research are left in this special version of XP, for
example there would be no need to install sound drivers, printer drivers, advanced graphics
applications etc. This helps reduce processor load and storage space used.
My two main methods of proposed transfer are using the FTP and BitTorrent protocols. Their
respective client / servers are listed above and they provide the best mass usage as they have
both been tested under heavy load 40. This will ensure maximum uptime from the software and
therefor accurate results.
All the above software contains logging sections, however to improve accuracy I will also use
external software to monitor as much as possible without interfering with the performance. I also
need to limit the capacity / bandwidth of each virtual machine, and software which allows me to do
this is Net Peeker. Net Peeker is also an ideal solution because it can be run on the server and
provide statistics on packet transfers to backup the individual statistics on each virtual machine.
The initial test-run allowed me to check the software configuration, whilst using user groups for
information on best performance settings.41 42
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After the initial set-up and testing of systems it was clear to see that the overheads incurred by
using the above set-up were too high for consistent data transfers. This was primarily due to
limitations imposed by Windows XP, VMWare and my method of viewing the remote machines,
VNC. Windows XP will not allow for more than 3 virtual machines to be run at once, VMWare is
very inefficient for resource allocation and VNC uses a sizeable portion of the network bandwidth
so when I connect to the clients I am actually impeding the flow of data (appendix 7.3.8.1). This
was not a problem for the server as there was ample bandwidth (1000mbit) available (appendix
7.3.7.2).
I decided to change the method of set-up drastically before too many tests were run in an effort to
control the tests with greater accuracy. The solution I decided upon was the following:
Server:
• Windows XP
• Microsoft IIS (FTP + HTTP server)
• BitComet Tracker (Torrent tracker)
• uTorrent (Torrent server)
• VNC (Remote viewing)
• Net Peeker (Network Speed Limiter/Monitor)
Clients:
• Windows Server 2003
• Allows for more than 3 RDP connections
• 4x RDP connections from a remote host
• RDP is controlled at the host computer level, not virtual client level so does not affect
bandwidth on the virtual clients
• Azureus (Torrent client)
• Azureus allows for binding of IPʼs on each virtual client, as there are multiple virtual interfaces
due to the RDP method used
• Net Peeker (Network Speed Limiter/Monitor)
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A diagram (section 7.3.11.1) showing the original flow of data helps to understand the complexities
of the above set-up. This diagram is for the planned (first) set-up. As you can see it produces many
connections from each virtual client (VClient). This in turn restricts bandwidth available to each
virtual client and affected the test dramatically in terms of both stability and performance.
With the refined set-up (section 7.3.11.2) it is clear to see that the number of connections are now
drastically reduced, and more importantly they originate from the physical client machines rather
than the virtual clients. As each physical machine is connected at 1000mbit with 4 virtual machines
which are each capped to up to 8mbit (depending on test criteria) it is now possible to allocate a
large portion of bandwidth to “services” and administration without affecting the test.
With such a number of virtual machines I need a system of organisation. On the “viewing
client” (my personal computer) I used a free application called CoRD to RDP into the clients. Once
set-up I also utilised Mac OSXʼs feature called “Spaces” which allows you to have multiple
desktops to better organise your applications. I opened a connection to each client in a different
“space” which resulted in the setup detailed in section 7.3.9.2.
As for the server part of the system, I had decided to use Windows XP as opposed to a server
based OS because the tasks it was performing were fairly basic. Windows Server will usually come
prepared with masses of services (active directory, domain services, printer services etc.) which
would simply not be used. Instead of installing a “server” operating system and then reducing it
down for my needs, it was simpler to run XP and build up to what I needed.
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4.2.3 Selection Algorithm
As previously stated, I wanted the system to buffer as many movies as possible, but as this could
be a fairly random process, I designed an algorithm to select movies based on the users viewing
habits.
For the testing I didnʼt actually use the algorithm because I was concentrating on the more
technical side of the project, however I feel it is an important asset to the project as a whole. The
algorithm is located in the appendix section 7.3.10, written in psuedo-code 43, but I will attempt to
give a basic outline of what it does here:
The algorithm:
• creates and clears variables for first use
• opens connections to the local and remote database
• local DB contains a list of movies on the client and what they have viewed
• remote DB contains a list of all movies available on the server
• checks to see if there are any matches based on the following criteria and their weightings
• (weightings are based on my personal habits and can be changed based on further research)
• genre(s) - 40% weighting
• actor(s) - 20% weighting
• writer(s) - 10% weighting
• director(s) - 10% weighting
• producer(s) - 10% weighting
• sound designer(s) - 5% weighting
• director(s) of photography - 5% weighting
• produces a list of movies to download based on the above, sorted by ranking
• closes the DB connections
After this, the system can check the list of movies and prioritise the downloads. The intended effect
is that users will have a choice, but where the amount of movies available to buffer is low (on lowbandwidth connections) the system can attempt to buffer movies which the user might find
enjoyable.
Further research is needed to figure out what factors people watch movies based on their previous
viewing. It is possible that some people, for instance, simply choose what movie to watch based on
its name. The point of this algorithm is that it can be adapted after more research has been
completed.
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4.2.4 Financial
Financial responsibilities for this project have been kept to a minimum. However items which
potentially required financing are identified below.
• Any hardware components which fail before or during the test - $300/£150/10,000฿
• Actual cost $50/£25/1,500฿ for a broken power-supply
• Electricity costs for running 4 machines for an extended duration - $200/£100/7,000฿
• Difficult to judge actual cost but probably around 3,000B
• (4 machines @ 400W each running for 10 weeks at a cost of 11B per unit)
• Licensing of software
• Windows XP
• I already own a subscription to MSDN which allows for 25 copies of XP to be used
simultaneously for development purposes
• VMWare Fusion
• $189/£90/6,300฿
• Net-Peeker
• $25 for server license, $15 x 12 for clients = $205/£100/7,000฿
• Additional literature required - $200/£100/7,000฿
This budget totals to $1094/£540/37,300฿. The amount stated above was planned for however at
the end of the project the total was around $800/£400/28,000฿.
n.b. The exchange rates have fluctuated throughout the year but the GBP value is accurate.
4.2.4 Human
For human resources I needed one academic supervisor to aid with research / project support and
one industry professional to aid with technical / practical support. I nominated Mr. Hardie Tucker as
my research / project supervisor, and Dr. Anthony Finkelstein44 for technical / practical support. I
have consulted with Dr. Finkelstein regarding my project and where he might be able to assist me.
I knew it would be extremely technical as he is head of the Computer Science department at UCL,
and he helped me greatly with the project as he specialises in Software Systems Engineering. I felt
that I still needed an “industry” contact, in the specific field I am dealing with. Luckily I managed to
find a family friend who was able to help. His name is Graham Skelton and he currently is the CEO
of CompleteTV45, an IPTV service provider in the UK. His assistance to me proved invaluable for
verifying market information.
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Chapter 5
5.1 Overview
This section details the findings of the above research in greater detail. As previously mentioned, I
conducted a questionnaire for people to respond to and the analysis of this data is provided below.
5.2 Results
All of the following analyses are based on the results from the questionnaire. These can be found
in the appendix (section 7.3.12)
5.2.1 Gender of Respondents
The gender of respondents isnʼt really crucial in the analysis of the data, however I attempted to
include roughly the same number of males as females. Unfortunately I received less replies from
females than males and so this must be taken into consideration when attempting to re-map
results from the sample population to the general population.
5.2.2 Location of Respondents
As the entire research is split between Thailand and the UK; I am studying in Thailand and I will be
moving back to the UK at the end of the course, location is a crucial factor in decoding the
following results. Based on this I want to obtain data from both countries and attempt to link
similarities and identify differences. I have successfully split the population sample close to 50%
UK and 50% Thailand. I believe that this will aid my analysis as I can obtain a fair comparison.
5.2.3 Amount of movies watched (Hours per week)
The respondents were asked how many hours per week on average they view movies, and
specifically movies. At this stage no attempt was made to obtain data on where the movies were
viewed and in what quality. I wanted this data as a base measure for analysing following questions.
It seemed that I managed to get a fair spread of results with some people even putting “0” as an
answer. This surprised me as “0” is very definite. In my opinion itʼs the same as saying “I do not
ever watch movies”. This maybe true however I doubt it. Regardless, the average was 7 hours per
week, or between 4 and 5 movies a week, which seems about right for me.
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5.2.4 Viewing Method
This question was one of my most crucial in the sense that it would give me information on the way
in which people watched movies. Not surprisingly the easiest method was also the most used, TV.
I believe TV is dominant because of its ease of use. It was encouraging to see that the next
biggest choice was PC. A third of my sample population is far higher than I anticipated. It is also
clear to me that going to the cinema is in clear decline, however to take one fifth of the results isnʼt
surprising as it is an established viewing method with features not found elsewhere (giant screen
etc.).
Now that I had established how much people watched and how they watched it I wanted to probe
deeper into my field of research, specifically HD content. For proper analysis of the following
information we have to take into account the location of the respondents as the availability of
services is different. Another factor is the “normal” prices paid for movies will be different as each
country has a different purchasing power parity. The method I learnt for easily identifying PPP was
that of comparing prices of a McDonalds Big Mac in each country, although it initially sounds stupid
it is actually a promoted method by The Economist46. Based on this I have found there to be a ratio
of 67B to £2.29, or an adjustment (based on exchange rates) of 120B/67B=1.79. This means that
any monetary value given by people in Thailand needs to be increased by 79% to have any sort of
meaningful comparison.
5.2.5 Amount willing to pay
As detailed above, the figures are corrected to allow for purchasing power differences from each
country. There were only 2 people who put a figure of “0฿”, which is best explained by them not
owning an HDTV. It makes sense that if you have no TV capable of displaying HD material then
why pay a premium for it?
It should also be noted that many (about 60%) of the respondents said that the amount they would
be willing to pay depended entirely on what content would be provided. Many people argued that if
they were unable to obtain new movies then the service wouldnʼt be worth it. One person even
went so far as to say that if it was available illegally then “Iʼd probably just download it”. This reassured my thought that the key to providing a successful service is content. Not one person
commented on the data-rates or the codecs or even the resolution of “HD” material being a
deciding factor. This disappointed me somewhat however it also helped me learn that this is
probably due to the viewers expecting a certain level of quality anyway, as soon as you mention
“HD”.
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5.2.6 Own an HDTV
The number of people owning an HDTV was re-assuring for me as over 2/3 of people said “yes”.
The interesting analysis of this was to compare the number of people with an HDTV and the
following result of the number of people with HD playback equipment:
5.2.7 Own HDTV Equipment
The question was asked; do you own any HD playback equipment. The results are surprising when
compared to the HDTV results above as it shows that while 2/3 of people have an HDTV, only 50%
have anything to enable HDTV viewing. In my opinion this is due to two factors; TV technology has
increased at a faster rate than the availability of HD playback devices and people are attempting to
“future-proof” their new TV purchase by buying above their needs. A TV is a substantial purchase,
one which many people wonʼt replace within a decade or so. With all the buzz and hype
surrounding HDTV, many consumers believe that they might need the HDTV functionality in the
future, regardless of their needs/habits. I also believe that this 20% difference is one of the groups
of people which my research attempting to target, the other being power-users.
5.2.8 Amount of HD Watched (per week)
This question was once of the most important to my field of research, in as much that it would
hopefully tell me how much people watched HD material currently. There are two ways to interpret
this data, one of which is to say that over half of the sample population do not watch any HD
material at all, therefor there is not much of a market to attempt to penetrate. The other way of
viewing this is that with the right product there are a lot of people who are open to the idea of HD
content. The best way to check to see if this hypothesis is correct is to select only the people who
answered “0” for this question, and look at the amount they would be willing to pay for HD content.
5.2.9 Amount Willing to Pay if no HD Viewed
Although the above result was fairly ambiguous, the chart shows that although some people didnʼt
watch any HD movies at all, only 18% of these wouldnʼt pay for the proposed HD service. It was
quite encouraging to see that the average amount these people were willing to spend was around
1000฿ v.s. 1400฿ for people who know the benefits of HD content.
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5.3 Project Activity
5.3.1 Pre-Buffer Data-Flow
Based on the results of the questionnaire and my previous experiences/learning's, it was apparent
to me that people didnʼt really care how their movies were broadcast to them, or even the
differences in HD quality the movies themselves were presented in. Because of this I decided to
design the system with this in mind.
The method of this is described in a detailed flowchart in the appendix section, however essentially
the system will test the clients internet connection and adapt both the method and buffer levels to
ensure flawless playback of the media. I have also allowed for 10% extra on both the buffer and
the remainder just in case the conditions of transfer change.
The way this works is best illustrated with the flowchart (appendix 7.3.13) and an example:
Movie length: 154 minutes
File-size: 4475 megabytes
Internet connection: 2 megabits/second
File pieces: buffer (including 5% test) + remainder
The system will test the internet connection by downloading 5% of the movie from central servers
(with potentially infinite bandwidth).
The system will then calculate based on this how much is needed to buffer in order to provide
flawless playback, in this case 55% or 2461 megabytes. This is calculated by the time taken to
download the remainder, as long as the following equation is satisfied then the movie can be
watched:
[((154 minutes x 60 x 2 megabits/sec) + 10%) > 2014 megabytes] or
[((movie length x 60 x maximum internet speed) + 10%) > remainder file-size]
The “x 60” is to convert the movie time into seconds (to match the internet speed)
The “+ 10%” is to allow for variations in the maximum internet speed. This is best explained by a
phenomenon called “network overheads”. Overheads are actually around 9.43% 47, however I
wanted the system to allow for differences in connections and 10% satisfied this.
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5.3.2 Results of the Tests
Based on the above I ran 8 tests in an attempt to establish minimum data rates and number of
movies available to watch on various connections per day. The results from these tests in a
broken-down format are available in the appendices.
The results were very encouraging as they were not far from what I had calculated; I had
previously calculated how much buffer each connection would need in optimum conditions. One of
the main purposes of the test was that as we all know the internet and IP networks in general
never run at full speeds and unexpected slowdowns do occur. I will be focussing on the actual
results from the tests in this section.
Something which I predicted was that running the model on a 1 megabit connection would provide
disappointing results with regards to the number of movies available for playback each day. By
researching the average movie length48, I used a film which was close to the 129 minute average
(Matrix Revolutions 49) and left the test machines running.
The results from this test from the viewing clients are available in the appendices (section 7.3.14),
however I will explain the findings here:
1 megabit connection
On a 1 megabit connection, the test movie (for average length) required 393 minutes to buffer and
a further 106 minutes to play, which is under the 129 minute movie length.
In reality this means that for one movie (of average length) on a 1 megabit connection to be ready
it takes about 6 1/2 hours to buffer. I expected a figure of around 371 minutes, or 6 hours 11
minutes. Already I was seeing a difference from what the hardware/networking should be providing
and what it really was. If we take the viewing hours of people from 6pm - 12am then this leaves us
with 18 hours left to use (from 12am -> 6pm) then we can only fit in 2 fully watch-able movies, as 3
would just push over the limit. As this is borderline then I would anticipate that 3 movies could
potentially be buffered, depending on exact viewing habits and internet usage on a 1 megabit
connection.
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On a 2 megabit connection the results were rather surprising. I had expected pretty much half the
time taken and around double the amount of movies available for viewing after a days test. Instead
I found that it took 143 minutes to fully buffer the test film. This is 2 hours and 23 minutes, much
less than 1/2 of the time taken on the 1 megabit test. The reasoning for this is that I had allowed for
half the time on the buffer and half the time on the remainder, however in reality it is not that simple
as the remainder time always needs to be 10% less than the run time of the movie.
What this means is that on a 2mbit connection we are able to buffer much less and still retain
“playability”. This of course means that within the 18 hour window (as explained above) we can
potentially have 7 movies available to view at the end of the day, far more than required for one
dayʼs viewing. With this in mind I predicted that the following (4 megabit) test would far exceed my
expectations in terms of the number of available movies.
The 4 megabit connection tests yielded some amazing results. The average length movie I was
using as a test was fully ready to be watched in just 18 minutes. A 4 megabit connection is not uncommon in either Thailand or the UK (my places of interest) and so this result really gave me
confidence that my methods were working. In theory it is possible, using this system, to have 60
movies ready to watch per day. This is obviously a lot more than is possible to watch in a day,
however the potential for choice is dramatically increased.
The algorithm which I had worked so hard on previously seemed to become fairly obsolete; I had
originally designed it to select which films to buffer in order to select relevant movies based on the
viewers preferences. The reasoning for this was that I thought that the system would only be able
to handle a few movies per day, however based on this test it becomes clear that it is possible to
have many movies ready for playback, in order to give people a greater choice.
The selection algorithm is still relevant because it will still rank movies which the user might enjoy
higher than others, just the amount of movies available for play has significantly increased.
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The previous tests had affirmed my calculations regarding content delivery, however I did not know
this before the tests ran. At this point as the 4 megabit test had provided so many available
movies, the 8 megabit test wasnʼt really necessary for me, however the test set-up had already
ran.
The results actually aided my research greatly as all of the tests failed completely. The results I
was getting were throwing back errors to do with “unable to connect to host” after the initial 5%.
What this meant is that the clients were unable to connect to the host computers (and other clients
using the P2P network).
I was shocked with this as all other tests had run completely and without many problems. I had to
investigate the problem further and what I learnt was that there was a problem with the calculation
used to decide on how much to buffer. I had to run the test manually and observe all of the
machines and the instructions given to them. What was happening is that the buffer size was being
calculated from the first 5% of the download. On an 8 megabit connection (after taking network
overheads automatically into account) the buffer size was actually negative as the connection was
so fast.
What this meant was that the clients were attempting to actually “reverse buffer”, or send data
which they didnʼt have back to the server. This is explained numerically in the appendices,
however obviously this was an error in the algorithm I was using to determine buffer size. On one
of the tests the client was attempting to send back around 70% of the movie (which it didnʼt have
yet).
Once I had corrected the formula used to calculate the buffer amount I re-ran the test. The 8
megabit connection didnʼt actually require any buffering at all, which meant that when I attempted
to play the movie, there was around a 2 minute delay before it would play, best explained by the
use of file-headers in the movie files I was using. This is normal for most computer data files as the
headers contain important information about the rest of the file, however it presented a problem for
me as the entire project has been designed with “flawless playback” in mind.
I decided to re-write the formula once again to make sure that regardless of the initial 5% buffer
(used to test the clients connection speed) it would always download an additional 5%, to give a
total of 10% minimum buffer amount. Once this test was run the results were on-track with what I
was expecting; instant start without any breaks in viewing.
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5.3.3 Summary of Results
Based on the above section I have drawn certain conclusions which aided me in my final test.
1. The system will work on any connection as long as it is at least 1 megabit
2. Only with an 8 megabit connection can we have a service close to true “on-demand”
3. Any connection in between will allow people to have a “pseudo-on-demand” service (where
previously none was available)
4. The algorithms and calculations are not perfect and will need constant attention to ensure as
few bugs as possible
5. The P2P network, even on a controlled local network, under-performed by around half
compared to what I had expected
6. All tests provided results which would satisfy both the average (7 hours / 3-4 movies) “number
of movies viewed per week” and the maximum (18 hours / 8-9 movies), gathered from the
earlier questionnaire
7. Another note is that the longer the movie being buffered is, the less time is taken to buffer. This
is because there is more time to download the remainder while the movie is being watched
5.3.4 Final Test
For the final test, I decided to take all of the above into account, whilst testing the system with a
longer (and therefor larger file-size) film. The film I used to test was “Pulp Fiction” 50. I used this film
as it is 154 minutes (2 1/2 hours) long, which is slightly longer than the average quoted above, in
order to test the system with a larger file-size movie.
I had wanted to use an even longer movie, “Titanic” (194 mins / 3 hours 15 minutes) for example,
however I didnʼt have an HD version of it to test with. The reasoning for using a “Hollywood” film as
opposed to indie content was that I personally know the film as I have watched it many times over
and they are usually available in HD. This in turn allows me to easily notice any flaws in playback,
be it smoothness, colours, audio/video sync issues etc.
I ran the final test on 4 different occasions, one for each simulated internet speed. Each test was
left to run from around midnight one night until around 6pm the following evening. As expected,
each of the tests completed successfully without any problems, as major problems had already
been identified in the earlier tests.
For 4 successive nights I watched Pulp Fiction from start to finish without any interruptions. The
results of the tests were extremely pleasing as I had achieved what I had set out to do. Further
details can be seen in section 7.3.16.
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5.4 Problems/Limitations of the system
From both my own observations and informal feedback from people I have discussed the project
with, there are certain issues which arise:
5.4.1 Power Usage
As the system has been designed to be running 24 hours per day there is an obvious concern over
power usage. In recent years, especially in the UK, both government and private organisations
have been lobbying for people to not waste as much energy as possible51 . This includes a basic
step of unplugging all devices which are in “standby” mode when not in use, especially over-night.
This causes significant problems for the structure of my system as it relies on using this “downtime” in order to function correctly. Essentially the system works by matching peoples down-time
with the systemʼs up-time, If people switch off the system during their down-time, the entire system
will not work. A possible work around to this is to clearly inform people to not power down the
device at all.
For this to work in todayʼs society, the system would need to be as efficient as possible with
regards to electricity usage. As I am not manufacturing the hardware for the system this is outside
of the scope of the project, however it is a genuine concern to be aware of.
5.4.2 Internet Connection Usage
The system has been designed to use only the idle portion of the internet connection. This is partly
achieved by the initial 5% speed test and partly by using QoS 52 (quality of service) rules. By telling
the internet gateway used (usually an ADSL/Cable modem/router) that the system is of the lowest
priority, all other internet traffic becomes a higher priority. For example if the system is using 100%
of the users internet connection and at the same time the user checks their e-mail, the system will
allocate the required amount to the e-mail application so as to not interfere with the usual use of
the connection.
The problem with this is that quite a few ISPʼs (internet service providers) will have a monthly limit
on the amount of data transferred. The amount of data the system uses is extremely high, due to
the nature of HD video. Users would have to be aware of this as they might run in to problems with
their ISP otherwise. For any situations where the system is used in a closed circuit (hotel, company
LAN etc.) this no longer becomes an issue. The project is focussed on the ability to provide a
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pseudo-on-demand service through any connection (over 1 megabit) and not with additional
limitations imposed by external companies.
A potential solution to this is that either the ISP makes an arrangement with the IPTV service
provider (to not include the transfers in the monthly data count), or simply the ISP becomes the
provider of the IPTV service. As this project isnʼt concerned with business agreements/licensing it
will not be discussed further, nevertheless it is an issue which arose while obtaining feedback from
one of my industry contacts.
5.4.3 Fast-forwarding
While testing the system it became apparent that one useful (and basic) feature of in-home
entertainment was unable to work in the system. Fast-forwarding, or skipping through the movie,
will not work due to the way the system has been designed. As there is no data past a certain point
(as it is still being downloaded) fast forwarding is not possible.
I tried to establish a point at which fast forwarding would work; when the entire movie has been
downloaded fully, however this usually indicates that the movie has already been watched. I have
not built any kind of fast-forward criteria into the system due to time constraints, however initially I
believe the simplest solution is to not allow fast forwarding at all. This falls in line with my personal
preference of wanting to watch a movie from start to finish in its entirety, much the same as when
viewing a film in a cinema.
The ability to pause the movie has been allowed in the current model of the system as this helps
the amount of downloaded data to be increased and therefor it only aids the end goal of playing
back without network/data interruptions.
5.4.4 Licensing
Based on the earlier questionnaire and feedback from industry professionals, the single most
limiting factor to the commercial success of this project is that of licensing. As previously
mentioned by a questionnaire respondent, “content is king”. All of the testing has been done in
private and with “educational licence” in mind, however in the public sector, licences would need to
be obtained for content, and obtaining more popular content potentially means more people would
be interested in investing into the service.
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5.5 Potential Benefits of the System
5.5.1 Advertising
As the system relies on the media file to be split up into parts for the distribution method, it is
potentially easy to add in advertising or previews of other movies to the beginning of the requested
content. This also means that the “negative” aspect of losing the ability to fast forward, as detailed
above, can be turned into a “positive” as advertisers would be more inclined to invest into a
medium in which they can get guaranteed views.
The possibility for the aforementioned 5% “bandwidth test” to be paid for by advertising also
presents us with a neat solution; the data costs of the servers bandwidth would be offset with the
revenues from advertisers. This is of course a business bonus, rather than a research bonus, but it
is extremely relevant when looking towards the future of the project.
5.5.2 Content Rights
Although the system has been used with a single codec, based on the specialised application part
of the course, it is possible to modify the files properties or even change the codec method
altogether. As long as the codec used is “sequential”, that is the beginning of the movie is at the
beginning of the file and the end of the movie is at the end of the file, it will work with the system.
Because of this, it is possible, although not necessary, to include content management systems
within the files being distributed. In a real-life scenario this allows for far greater control of where,
how and when the content is allowed to be viewed. Personally I do not really agree with the limiting
systems, but unfortunately many of the major studios do.
It is possible to allow multiple options for viewing based on the users needs; renting, buying or
blanket licence. Renting movies would be set-up in such a way that the user “pays per view” of a
movie, usually with certain restrictions on the availability of the content, licence expiry after 3 days
for example (much like the traditional “BlockBuster”53 model).
With the purchasing method, the user would essentially buy a licence to view the content, usually
with restrictions on where they can playback (much like a Blu-Ray Disc54 ). The method which I
favour is the “blanket licence” model. This basically means that while a user subscribes to the
service they are allowed to view as much content as they wish. There would still usually be
restrictions in force, for example if a user stopped paying for it, they would loose their privileges to
view the content. This model is currently employed by Sky 55, a UK based satellite company.
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5.5.3 Indie Producers
There is room in the system to allow users themselves to add content to the library, similar to
YouTube56 . This would mean that producers of independent content are able to enjoy the same
benefits studio productions do; retaining high quality picture and sound all the way to the viewer.
Also with the selection algorithm employed in the project, indie movies which people wouldnʼt
usually watch might get more attention than normal.
If we look at another part of the industry where this is already happening, itʼs clear to see that
recently (within the last 2 years), independent producers of all sorts are breaking into the market
much more than previously. A specific example is that of the “AppStore57 ” from Apple Computers 58.
Apple have opened up a market which is populated by both large companies and independent
producers of software applications, specifically for use on their iPhone59/iPodʼs 60.
This model was challenged by many industry professionals, however there have been many
“success stories” of independent producers creating popular applications for the general public61 .
One example of this is an application called “Trism” by Steve Demeter62 . The article claims that he
made a profit of around $250,000 in 2 months after releasing the application. Although this is
based on software, the principles are the same; users are buying a licence to use the application
which was made by an independent developer all conducted within a trusted marketplace.
5.5.4 Expandability
The client systems retain the ability to be updated by the servers at any time. For example if a bug
is found in the client, all other clients can be updated with a bug-fix, with no user interaction
whatsoever. This is something which has not been included in this project as I felt it was “overkill”
as I was sat next to all of the clients and due to the virtual machine nature of the test-bed.
5.5.5 Data Amounts
The system was designed principally with the aim to playback HD content whilst adapting to current
networking limitations. One off-shoot of this is that the load placed on the central server was greatly
reduced, when compared to the total amount of data requested from all of the clients. While each
test film was 3750mb, and being sent to 12 clients, we could expect a total of 45,000mb (45gb) to
have been sent from the server. However due to the peer to peer aspect of the system this figure
was around 15,000mb (15gb).for the initial tests. The remainder of the data was sent through the
peer to peer network, significantly reducing the load on the server by a factor of 3.
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Chapter 6
6.1 Conclusions
If we refer back to the original statement, “Design and Testing of On-Demand Distributed Content
Models for Distribution of High Definition Media Over IP Networks” clearly as long as basic criteria
are satisfied, the project is a “success”. I designed and tested an on-demand model for HD media
over IP networks. In this right the project was successful in proving that it is at least possible.
However I had set out some further criteria to allow me to provide a conclusion; the playback of the
content must be in high-definition (this was based on my specialised application work and the
questionnaire) and it must be “flawless” e.g. no breaks in viewing. Based on the analysis of the
project given above I can say with certainty that I have achieved these goals.
Based on the questionnaire, people are not that “fussy” when it comes to how “high definition”
something really is. I believe that if you simply told someone the content they were watching was
presented in HD, when in reality it was simply up-scaled SD material, 95% of the time they would
believe you. Regardless of this I had certain standards to uphold and the results from the earlier
tests revealed that HD content neednʼt take up masses of data. The perceived quality was still
indistinguishable from uncompressed HD footage.
Once the initial calculations were complete it was difficult to tell if the project would work correctly
under “real-life” situations, however as previously mentioned it exceeded my expectations. Once a
few bugs had been addressed, the playback of content was perfect, both the high definition video
and Dolby Digital 5.163 sound. Although both audio and video streams are compressed, the
majority of users will be used to this from previous formats (DVD, Blu-Ray etc.) and furthermore
already have the hardware needed for playback.
In conclusion, I feel that the only set-back to this project being taken further is the issue of
licensing. As we have established that “content is king”, without any “decent” content for viewers to
watch, why would they invest in service such as this?
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6.2 Recommendations
Working with such technical data on a project similar to this raises many problems and only the most
technically-comfortable of individuals should attempt it. I have had nearly 10 years being actively
involved in the IT industry and yet still found this project challenging.
Ideally for anyone wanting to do similar research to me I would recommend them to first read this paper
and ideally be able to understand the principle data flowʼs and algorithms. Once that is established
some good points of reference would include the book “The Technology of Video & Audio Streaming” by
David Austerberry 64. This book has provided an invaluable information source, however as industries
move at a fast pace I would recommend to obtain the most up to date version along with supplementing
this information with external sources.
I would also recommend that people who wish to undertake a project similar to this focus on simply one
country or location. I decided to focus on two locations because I was living in Thailand and was aiming
to move back to the UK after my studies had completed. Although I thought at the time this was the best
choice, it caused quite a few problems during my research and data-gathering; working with different
time-zones is something to be wary of, along with varying levels of technology and finally when
comparing monetary figures it is difficult to provide an accurate analysis due to the exchange rate being
so volatile during my year of study.
Although I was happy with my final results from the questionnaire, I would strongly recommend that in
future, researchers attempt to gain a larger sample population. It was difficult co-ordinating across
countries and I still feel that 21 people wasnʼt enough. As previously mentioned, data accuracy was an
issue, however I believe had I asked people in the street I might have got more accurate results than
my initial questionnaire.
With regards to the testing methods employed, I would recommend future researchers attempt to have
a more wide-spread testing set-up. I tried my best to simulate high demand however there is only one
of me and so viewing 12 separate video streams checking for any problems in playback was
impossible. I attempted to judge this from playback logs however what a program logs and what it really
does is sometimes quite different. This could be achieved by perhaps setting up 3 or more viewing
stations and requesting people use the system simultaneously and check for a flawed playback.
Finally as previously mentioned the amount of content and the source of the content is a high priority
both for testing and for any future development of the project. It would be advisable to do a full test with
an “industry standard” file with DRM included (for example from the iTunes HD Movie Store) however
these files are not made public at this stage, usable only with an AppleTV6566 . I feel it is important to
design the system with as few limitations as possible so as to be able to expand it in the future (music/
game distribution etc).
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Chapter 7
7.1 Endnotes
1
http://www.engadget.com/2008/03/19/fcc-redefines-broadband-to-mean-768kbps-fast-to-mean-kinda/
2
http://www.roughlydrafted.com/RD/RDM.Tech.Q2.07/3FE4864A-FC79-4EAD-BCB3-45C0B0C830BD.html
3
http://cityroom.blogs.nytimes.com/2007/11/14/off-goes-the-power-current-started-by-thomas-edison/
4
http://www.socialmedia.biz/2006/12/convergence_and.html
5
http://www.buzzle.com/editorials/4-10-2005-68350.asp
6
http://dictionary.reference.com/browse/model
7
http://www.dummies.com/how-to/content/entering-the-world-of-hdtv.html
8
http://www.starlancs.com/EducateMe/educate_IP_stack.html
9
http://www.thefreedictionary.com/network
10http://www.telechoice.com/bios_dbriere.asp
11
http://www.telechoice.com/bios_dbriere.asp
12
http://www.telechoice.com/default.asp
13
http://books.google.com/books?id=YY41cKhmsjYC
14
Briere & Hurley, 2007, P86
15
http://broadcastengineering.com/david-austerberry-editor/
16
http://www.intel.com/technology/mooreslaw/index.htm
17
http://www.dti.gov.uk/files/file13434.pdf
18
http://www.opsi.gov.uk/Acts/acts1998/ukpga_19980029_en_1
19
http://www.1st-free-music-download.com/napster.html
20
http://en.wikipedia.org/wiki/File:Standard_video_res.svg
21
http://education.jlab.org/beamsactivity/6thgrade/vocabulary/index.html
22
http://www.vmware.com/
23
http://www.bolton.ac.uk
24
http://data.bolton.ac.uk/bissto/researchskills/research_method/data_collection/triangulation.htm
25
http://www.statistics.gov.uk/cci/nugget.asp?id=1659
26
http://www.media-awareness.ca/english/resources/research_documents/statistics/television/
tv_viewing_habits.cfm
27
http://brent.tvu.ac.uk/dissguide/hm1u3/hm1u3text3.htm
28
http://forum.doom9.org/
29
http://www.mariposahd.tv/
30
http://www.imdb.com/title/tt0110912/
31
http://www.intel.com/products/processor/pentium4/index.htm
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32
http://www.smc.com/index.cfm?event=viewProduct&cid=6&scid=24&localeCode=EN_USA&pid=1147
33
http://www.vmware.com/
34
http://www.microsoft.com/windowsxp
35
http://filezilla-project.org/
36
ibid.
37
http://www.bitcomet.com/tools/tracker/index.htm
38
http://azureus.sourceforge.net/
39
http://www.net-peeker.com/
40
http://www.bitcomet.com/tools/tracker/index.htm
41
http://forums.afterdawn.com/
42
http://forum.doom9.org/
43
http://www.cs.cornell.edu/Courses/cs482/2003su/handouts/pseudocode.pdf
44
http://www.cs.ucl.ac.uk/staff/a.finkelstein/
45
http://www.completetv.com/
46
http://www.economist.com/markets/bigmac/
47
http://pflog.net/dsl_overhead/
48
http://www.infinitypoint0.com/60/imdb-film-length-project/
49
50
51
http://www.energysavingtrust.org.uk/What-can-I-do-today/Britain-Unplugged
52
http://www.cisco.com/en/US/docs/internetworking/technology/handbook/QoS.html
53
http://www.blockbuster.co.uk/
54
http://www.blu-ray.com/
55
http://www.sky.com/
56
http://www.youtube.com
57
http://www.apple.com/iphone/features/appstore.html
58
http://www.apple.com
59
http://www.apple.com/iphone/
60
http://www.apple.com/ipodtouch/
61
http://blog.wired.com/gadgets/2008/09/indie-developer.html
62
http://blog.wired.com/gadgets/2008/09/app-store-is-a.html
63
http://www.dolby.com/consumer/technology/dolby_digital.html
64
Austerberry, David “The Technology of Video & Audio Streaming” 2nd Ed. Focal Press 2005
65
http://www.apple.com/uk/appletv/
66
http://news.cnet.com/8301-17938_105-9850941-1.html
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7.2 References
1st Free Music Download. “History of Napster Technology” 1st-free-music-download.com. Accessed on 2nd January
2009.
AfterDawn. “AfterDawn Forums” afterdawn.com. Accessed on 2nd January 2009.
Amazon.com. “Matrix Revolutions (2003)” imdb.com. Accessed on 2nd January 2009.
Amazon.com. “Pulp Fiction (1994)” imdb.com. Accessed on 2nd January 2009.
American Psychological Association (APA). “model. (n.d.).” Webster's Revised Unabridged Dictionary. Retrieved 2nd
January, 2009.
Apple Computers. “AppStore” apple.com. Accessed on 2nd January 2009.
Apple Computers. “Apple” apple.com. Accessed on 2nd January 2009.
Apple Computers. “iPhone” apple.com. Accessed on 2nd January 2009.
Apple Computers. “iPod Touch” apple.com. Accessed on 2nd January 2009.
Apple Computers. “AppleTV” apple.com. Accessed on 2nd January 2009.
Austerberry, David. “The Technology of Video & Audio Streaming” 2nd Ed. Focal Press. 2005.
Bell, Donald. “iTunes HD Movie Rental only for Apple TV?” cnet.com. Accessed on 2nd January 2009.
BitComet. “A Free BitTorrent Client” bitcomet.com. Accessed on 2nd January 2009.
Blockbuster. “Blockbuster” blockbuster.co.uk. Accessed on 2nd January 2009.
Blu-Ray. “Blu-Ray” blu-ray.com. Accessed on 2nd January 2009.
Briere, Danny and Pat Hurley. “HDTV for Dummies” Wiley Publishing, 2007.
BSkyB. “Sky TV” sky.com. Accessed on 2nd January 2009.
Chen, Brian X. “iPhone Developers go from Rags to Riches” wired.com. Accessed on 2nd January 2009.
Cisco. “Quality of Service” cisco.com. Accessed on 2nd January 2009.
Collins English Dictionary. “network. (n.d.)” Collins Essential English Dictionary 2nd Edition. (2004, 2006). Retrieved 2nd
January 2009.
CompleteTV. “CompleteTV” completetv.com. Accessed on 2nd January 2009.
Cornell University. “Pseudo-code” cs.cornell.edu. Accessed on 2nd January 2009.
Department of Culture, The. “Lifestyles” statistics.gov.uk. Accessed on 2nd January 2009.
Department of Trade & Industry. “Connecting the UK: the Digital Strategy” dti.gov.uk. Accessed on 2nd January 2009.
Dilger, Daniel Eran. “Movie Studios vs. Consumers in Home Theater” Roughly Drafted. Accessed on 2nd January 2009.
Dolby Labs. “Dolby Digital” dolby.com. Accessed on 2nd January 2009.
Economist, The. “Big Mac Index” economist.com. Accessed on 2nd January 2009.
Energy Saving Trust. “Britain Unplugged” energysavingtrust.org.uk. Accessed on 2nd January 2009.
FileZilla. “The Free FTP Solution” filezilla-project.org. Accessed on 2nd January 2009.
“Hellisp”. “Standard Video Resolutions” wikipedia.org. Accessed on 2nd January 2009.
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Hurley, Patrick J. “A Concise Introduction to Logic” Thomson/Wadsworth, 2006.
Infinity point 0. “Film Length Project” infinitypoint0.com. Accessed on 2nd January 2009.
Intel. “Moores Law” intel.com. Accessed on 2nd January 2009.
Intel. “Pentium 4 Processor” intel.com. Accessed on 2nd January 2009.
Jelsoft Enterprises. “Doom9ʼs Forum” doom9.org. Accessed on 2nd January 2009.
Jin, Ming. “Net-Peeker” net-peeker.com. Accessed on 2nd January 2009.
Lasica, J.D. “Convergence & Cultural Change” Social Media. Accessed on 2nd January 2009.
Lee, Jennifer. “Off Goes the Power Current Started by Thomas Edison” New York Times. Accessed on 2nd January
2009.
Media Awareness Network. “Statistics on TV Viewing Habits (1994-2000)” media-awareness.ca. Accessed on 2nd
January 2009.
Microsoft. “Windows XP” microsoft.com. Accessed on 2nd January 2009.
Motamorfosis Productions. “Mariposa HD” mariposahd.tv. Accessed on 2nd January 2009.
Office of the Public Sector Information. “Data Protection Act 1998” opsi.gov.uk. Accessed on 2nd January 2009.
Parekh, Nilesh. “Software Testing - White Box Testing Strategy” Buzzle. Accessed on 2nd January 2009.
Penton Media. “David Austerberry” broadcastengineering.com. Accessed on 2nd January 2009.
pflog. “DSL Overheads” pflog.net. Accessed on 2nd January 2009.
SMC Networks Inc. “SMC8508T Switch” smc.com. Accessed on 2nd January 2009.
Sorrel, Charlie. “AppStore is a Goldmine” wired.com. Accessed on 2nd January 2009.
Sourceforge. “Azureus BitTorrent Client” sourceforge.net. Accessed on 2nd January 2009.
Sparrow, Andrew. “Film & TV Distribution and the Internet” Gower, 2007.
Stallings, William. “Computer Organization & Architecture” Prentice Hall, 2003.
StarLAN. “TCP/IP Stack Explained” starlancs.com. Accessed on 2nd January 2009.
TeleChoice. “Danny Briere” telechoice.com. Accessed on 2nd January 2009.
Thames Valley University. “Primary Data Collection Methods” tvu.ac.uk. Accessed on 2nd January 2009.
Thomas Jefferson National Accelerator Facility. “Vocab List” education.jlab.org. Accessed on 2nd January 2009.
University College London. “Dr. Anthony Finkelstein” cs.ucl.ac.uk. Accessed on 2nd January 2009.
University of Bolton, The. “Triangulation” bolton.ac.uk. Accessed on 2nd January 2009.
VMWare. “VMWare: Virtual Machines” vmware.com. Accessed on 2nd January 2009.
Wiley Publishing. “Entering the World of HDTV” Dummies.com. Accessed on 2nd January 2009.
YouTube. “YouTube” youtube.com. Accessed on 2nd January 2009.
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7.3 Appendices
7.3.1 Scan from “HDTV for Dummies” page 86
7.3.2 SD/HD Resolution Comparison Table
Source: http://en.wikipedia.org/wiki/File:Standard_video_res.svg
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7.3.3 Course Flowchart
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7.3.4 Example Questionnaire
Hey guys, reckon you could help me out with my research and answer this quick
questionnaire?
Please be honest, it's all anonymous and not a competition!
Feel free to add options if nothing suits you (UK people just put the prices in pounds)
This is all about MOVIES, not TV series or anything else, just MOVIES:
How many hours per week do you watch movies?
| 0-2 hours | 2-5 hours | 5-10 hours | 10-15 hours |
What method do you primarily use (Cinema, TV, PC, PS3, PSP, Mobile Phone...)
| Cinema | TV | PC/Laptop | PS3/Xbox | PSP/PMP | Mobile Phone |
Do you own an HDTV?
| Yes | No |
Do you own any equipment which plays HD? (PC, Blu-Ray player, PS3 etc.)
| Yes | No |
How often do you watch HD content? (Hours per week)
| 0-2 hours | 2-5 hours | 5-10 hours | 10-15 hours | N/A |
How much would you pay (per month) for unlimited HD content on your device of choice?
| 0฿ | 500฿ | 1000฿ | 1500฿ | 2000฿ | More than 2000฿
Thank you for your time,
Mat.
Page 47 of 75
Mat Thomas
S75245/BAFM1107
7.3.5 Project Schedule
Month
Project
Activity
January
February
March
Write Proposal Research/analyze Research/
viewing trends
develop virtual
Research virtual
test systems
machine methods/
limitations
Sideline
Activity
Download 40
hours of 1080p
material
Deadlines
4th - Proposal Due 31st - Have
Systems in
Place
Month
July
August
April
Run a test
system and
check for
accuracy
September
3rd week Begin first
test
October
Collect results Prepare final
from last 4 test solution, refine
runs, analyze
and note
findings.
Collect results Refine
from final test, research
analyze, note results
findings and
conclude
Sideline
Activity
Download
further
material for
final test
Work
placement
Deadlines 31st - propose 2nd week - run
a final solution proposed test for
for further
2 weeks
testing
30th Complete
findings
3rd week 1st draft of
complete
paper
June
Collect results from Collect results from
first test run, check first 4 test runs,
accuracy
analyze and note
findings.
Convert 1080p (1 week off
material into
for Songkran
other formats Festival)
Project
Activity
Work placement
May
(Last week off for
birthday)
1st week - 2nd test 1st week - 6th test
2nd week - 3rd test 2nd week - 7th test
3rd week - 4th test 3rd week - 8th test
4th week - 5th test
November
December
Refine final paper
Prepare for
presentation
26th - Completed Research
Research & Project Presentation
Page 48 of 75
Mat Thomas
S75245/BAFM1107
7.3.6 Hardware Testing
Picture taken on 12/11/08
Page 49 of 75
Mat Thomas
S75245/BAFM1107
7.3.7.1 Server - Installing Windows XP
Page 50 of 75
Mat Thomas
S75245/BAFM1107
7.3.7.2 Server - Network Speed
1 Gbps = 1024 Mbps
Page 51 of 75
Mat Thomas
S75245/BAFM1107
7.3.7.3 Server - Network Analyser
n.b. the only process using bandwidth is the peer to peer tracker
Page 52 of 75
Mat Thomas
S75245/BAFM1107
7.3.7.4 Server Configuration
Installing IIS (Internet Information Services) to allow for FTP server
Page 53 of 75
Mat Thomas
S75245/BAFM1107
Installing peer to peer network services
Page 54 of 75
Mat Thomas
S75245/BAFM1107
7.3.7.5 Server - Splitting of Media File
Total size: 4475mb
Split size:
89.5mb
Number of files
100
The split files allow for one piece to equal 1% of the total file, to allow for easier allocation based
on the client network speed.
Page 55 of 75
Mat Thomas
S75245/BAFM1107
7.3.8.1 Client - Network Analyser
n.b. “Process 1396” in green is VNC, a screen sharing application.
12.56K/sec is around 15% of the available bandwidth on a 1mbit connection.
Page 56 of 75
Mat Thomas
S75245/BAFM1107
7.3.8.2 Client - Simulating ADSL Bandwidth
n.b. KB/s x 8 = kbps
Upload: 64KB/s = 512kbps
Download:
256KB/s = 2048kbps (2 megabit)
Page 57 of 75
Mat Thomas
S75245/BAFM1107
7.3.9.1 Viewer - Connection to Server
Page 58 of 75
Mat Thomas
S75245/BAFM1107
7.3.9.2 Viewer - Method
Page 59 of 75
Mat Thomas
S75245/BAFM1107
7.3.10 Viewing Bias Code
All code is written in pseudocode, guidelines:
http://www.cs.cornell.edu/Courses/cs482/2003su/handouts/pseudocode.pdf
‘Begin Code
‘---------‘Basics
‘-----Local [New] as Array(...)
available
Local [ForDL] as Array(...)
Local [Score] as Integer
Global [Match] as Array (...)
‘Signifies whether any new content is
[New]
[ForDL]
[Score]
[Match]
‘Cleaning out all variables for first use
==
==
==
==
“”
“”
“”
“”
‘Ranked list of what to download
‘Holds the “score” of each content
‘Keeps lists of potential matches
OpenConnection(LOCAL) as Object
Local.Authenticate
‘Connect to the local database
‘Authenticate with the local server
OpenConnection(REMOTE) as Object
Remote.Authenticate
‘Connect to the remote database
‘Authenticate with the remote server
‘Rankings
‘--------‘Genre (40%)
‘Actor (20%)
‘Writer (10%)
‘Director (10%)
‘Producer (10%)
‘Sound (5%)
‘DP (3%)
WHILE i <= Remote.Count DO
‘Check all available movies on server
IF Remote.Film(i).Genre = Local.Film.Genre(AVERAGE(MODE)) THEN
[Match].Genre = Remote.Film(i)
[Score] = [Score].Remote.Film(i) * 0.4
END IF
IF Remote.Film(i).Actor = Local.Film.Actor(AVERAGE(MODE)) THEN
[Match].Actor = Remote.Film(i)
END IF
IF Remote.Film(i).Writer = Local.Film.Writer(AVERAGE(MODE)) THEN
[Match].Writer = Remote.Film(i)
END IF
IF Remote.Film(i).Director = Local.Film.Director(AVERAGE(MODE)) THEN
[Match].Director = Remote.Film(i)
END IF
IF Remote.Film(i).Producer = Local.Film.Producer(AVERAGE(MODE)) THEN
[Match].Producer = Remote.Film(i)
END IF
Page 60 of 75
Mat Thomas
S75245/BAFM1107
IF Remote.Film(i).Sound = Local.Film.Sound(AVERAGE(MODE)) THEN
[Match].Sound = Remote.Film(i)
END IF
IF Remote.Film(i).DP = Local.Film.DP(AVERAGE(MODE)) THEN
[Match].DP = Remote.Film(i)
END IF
i++
END WHILE
SWITCH
CASE [Match].Genre EXISTS THEN
[ForDL] = [ForDL] + [Match].Genre
BREAK
CASE [Match].Actor EXISTS THEN
[ForDL] = [ForDL] + [Match].Actor
BREAK
CASE [Match].Writer EXISTS THEN
[ForDL] = [ForDL] + [Match].Writer
BREAK
CASE [Match].Director EXISTS THEN
[ForDL] = [ForDL] + [Match].Director
BREAK
CASE [Match].Producer EXISTS THEN
[ForDL] = [ForDL] + [Match].Producer
BREAK
CASE [Match].Sound EXISTS THEN
[ForDL] = [ForDL] + [Match].Sound
BREAK
CASE [Match].DP EXISTS THEN
[ForDL] = [ForDL] + [Match].DP
BREAK
END SWITCH
LOCAL.[ForDL] SORT BY [Score]
LOCAL.Download [ForDL]
‘List the films but ranked by score
‘Download the films by score
CloseConnection(LOCAL)
CloseConnection(REMOTE)
‘End Code
‘--------
Page 61 of 75
Mat Thomas
S75245/BAFM1107
7.3.11.1 Original Virtual Data Flow Diagram
Client 2
Client 1
Server
Client 3
VClient1
VClient2
VClient5
VClient6
VClient9
VClient10
VClient3
VClient4
VClient7
VClient8
VClient11
VClient12
1000mbit Switching Hub
Viewing Client
7.3.11.2 Refined Virtual Data Flow Diagram
Client 2
Client 1
Server
Client 3
VClient1
VClient2
VClient5
VClient6
VClient9
VClient10
VClient3
VClient4
VClient7
VClient8
VClient11
VClient12
1000mbit Switching Hub
Viewing Client
Page 62 of 75
Mat Thomas
S75245/BAFM1107
7.3.12.1 Questionnaire Results
Page 63 of 75
Mat Thomas
S75245/BAFM1107
7.3.12.2 Questionnaire Analysis
Age
Amount watched (hours/week)
Gender
Viewing Method Location
Amount Willing To Pay
Page 64 of 75
Mat Thomas
Own an HDTV
S75245/BAFM1107
Own HDTV Equipment Amount of HD Watched (hours/week)
Amount Willing to pay if no HD viewed
Page 65 of 75
Mat Thomas
S75245/BAFM1107
7.3.13 Data Flow Decisions
Page 66 of 75
Mat Thomas
S75245/BAFM1107
7.3.14 Initial Testing Results
Uploaded Uploaded
(torrent)
(FTP)
Uploaded
(netpeeker)
(Upload
total)
Downloaded Downloaded
(torrent)
(FTP)
Downloaded
(netpeeker)
(Download
total)
Client 1 (1mbit)
Client 2 (2mbit)
Client 3 (4mbit)
Client 4 (8mbit)
Client 5 (1mbit)
Client 6 (2mbit)
Client 7 (4mbit)
Client 8 (8mbit)
Client 9 (1mbit)
Client 10 (2mbit)
Client 11 (4mbit)
Client 12 (8mbit)
1,987
1,886
2,013
3,984
2,055
2,040
2,018
3,851
2,066
1,859
1,736
4,097
0
0
0
0
0
0
0
0
0
0
0
0
1,996
1,891
2,015
3,985
2,060
2,046
2,022
3,855
2,066
1,865
1,741
4,102
1,987
1,886
2,013
3,984
2,055
2,040
2,018
3,851
2,066
1,859
1,736
4,097
2,984
2,841
2,586
2,347
2,884
2,845
2,562
2,288
2,802
2,654
2,455
2,307
766
909
1,164
1,403
866
905
1,188
1,462
948
1,096
1,295
1,443
3,759
3,758
3,755
3,754
3,760
3,756
3,759
3,757
3,757
3,752
3,758
3,753
3,750
3,750
3,750
3,750
3,750
3,750
3,750
3,750
3,750
3,750
3,750
3,750
Server (1000mbit)
1,963
13,445
15,410
15,408
0
0
296
0
31,555
29,592
13,445
45,053
29,592
31,555
31,555
13,445
45,076
45,000
Totals
7.3.15 Penultimate Test Results
7.3.16 Final Test Results
Page 67 of 75
Mat Thomas
S75245/BAFM1107
7.3.17 Spec Sheet of Proposed Hardware (from module 301: Business Plan)
Mat Thomas!
S75245/BAFM1107
Specifications
Power
• Built in power supply
• Built in UPS
Internals
• Intel P4 processor
• 250GB HDD
• 2GB RAM
Externals
• Power Connector
• USB Port
• Network Port
• HDMI
• Component
• RCA Audio
• Optical Audio
• Wireless 802.11n
2
In the box:
• hi-vue
• hi-vue remote
• power cable
• HDMI cable
Size & Weight
• Footprint: 100x300mm
• Height: 300mm
• Weight: 1.5kg
TV Output
• HDTV compatible only
• Minimum: 720p
Software
• Hi-Vue OS (Based on Linux)
• Bootloader (Multiple OS’s)
• Hi-Vue media browser
• Hi-Vue media player
Formats:
• AVI
• MPEG2
• MPEG4
• H.264
• WMV
• .ts
• BD-DVD
• HD-DVD
• Maximum: 2k
Page 6 of 11
Page 68 of 75
Mat Thomas
S75245/BAFM1107
7.3.18 Specialised Application (from module 302: Specialised Application)
Mat Thomas!
S75245/BAFM1107
Introduction
Within this report I will attempt to present my findings with regards to the perceivable quality
differences between encoding/compression parameters of H.2641 video.
Hypothesis
The relationship between various settings of the encoding module of an H.264 video file and
perceivable quality by the user would tend towards a logarithmic curve if placed on a simple
filesize/quality graph, hence an optimum point must exist. A more simplified version of the above
hypothesis would be to say that as the file-size of a movie file increases, the benefits to a viewer
decelerate and that most people are unable to differentiate between marginal drops in quality.
Application
The results from the tests contained in this paper will allow for a better understanding of an
“optimum” point of file-size/quality for viewing movie files. If we are able to identify the “roll-off”
point (where increases in settings/file-size no longer have a major impact on the increase of
perceived quality changes) then we can restrict the amount of “wasted” data.
Learning Outcomes
At the end of this project I aim to have a greater understanding of the H.264 file format, more
specifically how the parameters of the encoding module affect the final product. For example, by
decreasing the FPS (frames per second), and therefor the amount of data contained in the file, will
I be able to tell the difference between the original, and if so, how much of a difference?
Activities
The first step in this project is to obtain uncompressed footage as the “control” movie file, as this
will be predominately an experiment format project. For this footage I have decided to shoot a
short clip myself, using my own equipment. I have decided that it is best to include the following
variables in the captured material; fast on-set motion, colour changes and luminance changes. I
chose to take a time-lapse from my apartment from mid-day until dusk, resulting in all of the above
needed factors and an 11 second clip. Once the clip has been transferred to a machine capable of
processing raw HD footage, it will need to be converted many times over to produce an array of
clips which can be analysed. Because the learning outcomes are very subjective and personal, I
must outline what I will be looking for in the clips before I can make judgements.
Page 3 of 16
Page 69 of 75
Mat Thomas
S75245/BAFM1107
Mat Thomas!
S75245/BAFM1107
This is a still frame capture of frame 1 from the uncompressed control file. I will attempt to identify
the overall “perceivable quality” based on the following factors:
Sharpness !
- Using the billboard (blue)
Motion!!
- Using the trees on the left and the clouds (yellow)
Colour!!
- Using the sunset from the sky and the turquoise building in the foreground (green)
Contrast!
- The difference between the top left and bottom right of the frame (red)
The selection boxes are an attempt to make the reviewing and analysis of clips more precise,
however for an overall score it is also necessary to look at the entire frame/clip to gauge an
approximate “perceived quality level”, as after all, this is what the research is concerned with.
Please note that due to PDF compression techniques 2, there is a possibility that the subtle
differences being evaluated in this paper could be lost.
Resources
• Mac with OS X Leopard3
• Quicktime Pro4
• Uncompressed 720p movie file with relevant indicators of perceived quality
• (The Technology of) Video & Audio Streaming, Austerberry, David, Focal Press, 2005
Page 4 of 16
Page 70 of 75
Mat Thomas
S75245/BAFM1107
Mat Thomas!
S75245/BAFM1107
Activity
1st September !
- Capture video
2nd - 6th September !- Convert video
8th September!
- Select clips for testing
9th - 12th September!- Analyse clips
15th September!
- Produce statistics/graphs from analysis
17th - 19th Sept.!
- Write-up introduction
22nd - 25th Sept.!
- Write-up reflections
26th - 29th Sept.!
- Proof read/references
As the video is in time-lapse format, it took most of the day to complete.
The video conversions had to be done manually and could take up to 3 hours to complete just one.
The selection of clips to be used was based on the resources and personal choice.
Page 5 of 16
Page 71 of 75
Mat Thomas
Mat Thomas"
S75245/BAFM1107
S75245/BAFM1107
Reflection on Personal Learning Outcomes
As I am already familiar with the reasoning for encoding/compression of video, and the industry
leaders, the technical aspect of this project went as smoothly as I had hoped. The ultimate aim of
learning about the finer details of the H.264 codec was very daunting, however. From my research
online and in books 5, I was able to gain a very good understanding of the parameters of video
encoding. I had already chosen to ignore the audio track so my focus was simply on the
parameters offered by the encoding dialogue of Apple!s H.264 video codec.
The above picture is what is presented by the encoder at the stage of output. It enables us to
change the following variables 6:
• Frame rate
• Number of key frames
• Data rate
• Encoding quality
• Number of encoding passes
Page 6 of 16
Page 72 of 75
Mat Thomas
Mat Thomas!
S75245/BAFM1107
S75245/BAFM1107
By altering the variables the preview (static frame) changes to give you a rough representation of
the output quality. This was not sufficient for my analysis as it is not a movie file and only
represents one frame of the clip, thus disabling me from analysing the majority of my test criteria.
There are some very complex mathematical calculations involved in the encoder section, which I
had to learn about before exporting the video required for the test. The equations used will not be
explained in this paper, however I will attempt to outline the key points which I learnt for the benefit
of the reader.
If we take the analogy of a pipe with water flowing through it for the video clip, the same analogy
used for general data flow of computer communications, then we can make the following links:
• The diameter of the pipe can be related to the data rate
• The amount of water in any cross-section of the pipe can be related to the quality
• The pressure of the water can be related to the frame-rate
In order to better understand the key-frames and the encoding passes we must use a different
analogy. Key-framing, with respect to video encoding, is much the same as key-framing in a Flash7
based environment; it is a very specific representation of that particular frame. In video encoding, a
keyframe is literally a picture of that frame, with non-keyframes holding only the differences
between itself and the previous frame.
I have learnt that key-framing is very useful in Flash based work as you can specify exactly what
frames should be keyframes; change of scene, detailed motion etc, and to use “tweens” in
between keyframes is a very efficient method of working. The downside to keyframes with respect
to video is that you cannot easily choose which frames need to be keyframes, simply “all, every x
frames or automatic. If a keyframe does not appear on the initial frame of a scene change, the
potential for creating unwanted data in the form of unnecessary equations to represent the
differences is greatly increased.
For example: a keyframe takes up 100kb of data while a simple change of the scene (someone
moving their lips while talking in an interview situation) will only take up 10kb of data, as we are
only storing the changes, in this case the lips, and nothing else. When the scene changes without
a new key-frame, the entire frame has changed and trying to represent this in an equation based
on the previous frame will undoubtably take up more than 100kb of data. Therefor it is actually
more efficient to insert a new key-frame rather than using the otherwise highly efficient
compression process.
Page 7 of 16
Page 73 of 75
Mat Thomas
S75245/BAFM1107
Mat Thomas!
S75245/BAFM1107
The problem we encounter here is how to choose the key-frames effectively. A method employed
by the encoder module is to first run through the entire clip and map out the changes frame by
frame, on a percentage basis. For example, in the above example of someone giving an interview,
most of the frames will only change by about 5-10%, however if the scene was to change to
something completely different, the change would be close to 100%. The encoder knows its own
efficiency levels and for example if the change was over 50% it would mark that frame to become a
key-frame.
The number of encoding passes is actually one of the most simplest parameters to understand,
once we cut through the discourse language: single pass encoding will attempt to fill out a constant
bit-rate (per frame) and a multi-pass will attempt to fill out to a file-size based on an average bitrate. This allows to distribute the amount of data either evenly throughout the file (single pass), or
wherever the data is “needed” most (multi pass). These two settings will produce a CBR (constant
bit-rate) file (single-pass), and VBR (variable bit-rate) file (multi pass).
Based on my learning of all of the above, it is clear to see that the data-rate is possibly the single
most important variable; if it is too high then you are wasting data, if it is too low then you will not
be able to fit in the required data. Because of this I decided to leave the data-rate set to automatic
(the encoder would fill out the data rate based on the other settings), leave the encoding on multipass (it is more efficient but takes more time to encode), and leave the key-framing on automatic
also (as detailed above the encoder can figure out when to insert key-frames).
Therefor I decided to produce the following files, all created from the control file so there was no
chance of re-compression artifacts:
Frame Rate
(FPS)
Key Frame
Every x
Frames
Data Rate
(kbits/sec)
Quality
(percent)
Encoding
File-size
(MB)
Control
25
All
60500
100
N/A
81.2
Quality 1
Quality 2
Quality 3
Quality 4
Quality 5
25
25
25
25
25
Auto
Auto
Auto
Auto
Auto
17358
4571
1043
625
531
100
75
50
25
1
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
22.8
6.0
1.4
0.8
0.7
FPS 1
FPS 2
FPS 3
FPS 4
FPS 5
24
23
22
21
20
Auto
Auto
Auto
Auto
Auto
16666
15939
15249
14628
13949
100
100
100
100
100
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
21.9
20.9
20.0
19.2
18.3
Page 8 of 16
Page 74 of 75
Mat Thomas
S75245/BAFM1107
Mat Thomas"
S75245/BAFM1107
Once I had these files, and before reviewing any
of them for perceivable quality, based on my
mathematical learning and observation, the
compressor quality vs file-size relationship was
non-linear as a 25% reduction in quality was over
300% reduction in file-size, affirming my initial
hypothesis.
By this stage I had already learnt the basics of encoding using the H.264 compression method,
however I wanted to refine the values based on combining more than one variable in order to hit
the “sweet spot” of perceivable quality vs file-size. To stick to the learning outcomes I would have
to ensure that this wasn!t a trial and error approach, so in order to do this I have to analyse the
above movie clips to result in a numerical form of perceivable quality (see appendices). Once this
is complete a refinement of clips can be made and then reviewed in a similar manner. A full
breakdown can be seen in the appendices, however the resultant movie files chosen are as
follows:
Frame Rate
(FPS)
Combine 1
Combine 2
Combine 3
Combine 4
Combine 5
24
24
23
23
22
Key Frame
Every x
Frames
Auto
Auto
Auto
Auto
Auto
Data Rate
(kbits/sec)
16666
4395
15939
4207
15249
Quality
(percent)
100
75
100
75
100
Encoding
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
Multi-Pass
File-size
(MB)
21.9
5.8
20.9
5.5
20.0
Based on the findings from the 10 initial clips, I set a threshold of 85% overall perceivable quality
and tested the above combinations. I have learnt that the setting of encoding quality affects the
file-size much more dramatically than the FPS, however as I intended to learn about the most
efficient settings, the combination of FPS and encoding quality both play a part in ultimate file-size.
Whilst maintaining an “85%” quality level and keeping file-size as low as possible, I conclude that
the “Combine 2” settings are the optimum for this particular clip. A decrease in perceived quality of
only 15% but a decrease in file-size by a factor of 14 times.
Page 9 of 16
Page 75 of 75

Design and Testing of On-Demand Distributed Content Models for

Transcription

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