VIDEO STREAMING THROUGH USTREAM 2013-2014 Dept. of IT, DSCE PAGE 1 ABSTRACT Streaming technologies are rapidly gaining popularity as a way to deliver dynamic media over the Internet. As bandwidth increase and compression technologies mature, it becomes increasingly easier to deliver real-time, dynamic media, such as video, audio, animation, Java applications and 3-D and vector graphic using streaming technologies. USTREAM is one such technology which allows user to access live events as and when they are happening. USTREAM technology is fashioned on a client-server model. It has gained popularity because most internet users do not have fast enough connections for downloading large multimedia files. In the streaming scenario, the client browser or plug-in starts playing dynamic data as soon as a sufficient amount of data has arrived from the streaming server. This directly contrasts with a static model of data delivery, where all the data is delivered to the client machine prior to actual playback. If used properly, streaming applications can add impressive capability to any site.
Streaming technologies are rapidly gaining popularity as a way to deliver dynamic media over the Internet. As bandwidth increase and compression technologies mature, it becomes increasingly easier to deliver real-time, dynamic media, such as video, audio, animation, Java applications and 3-D and vector graphic using streaming technologies. USTREAM is one such technology which allows user to access live events as and when they are happening. USTREAM technology is fashioned on a client-server model. It has gained popularity because most internet users do not have fast enough connections for downloading large multimedia files. In the streaming scenario, the client browser or plug-in starts playing dynamic data as soon as a sufficient amount of data has arrived from the streaming server. This directly contrasts with a static model of data delivery, where all the data is delivered to the client machine prior to actual playback. If used properly, streaming applications can add impressive capability to any site.
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VIDEO STREAMING THROUGH USTREAM 2013-2014
Dept. of IT, DSCE PAGE 1
ABSTRACT
Streaming technologies are rapidly gaining popularity as a way to deliver dynamic
media over the Internet. As bandwidth increase and compression technologies
mature, it becomes increasingly easier to deliver real-time, dynamic media, such as
video, audio, animation, Java applications and 3-D and vector graphic using
streaming technologies. USTREAM is one such technology which allows user to
access live events as and when they are happening. USTREAM technology is
fashioned on a client-server model. It has gained popularity because most internet
users do not have fast enough connections for downloading large multimedia files.
In the streaming scenario, the client browser or plug-in starts playing dynamic data
as soon as a sufficient amount of data has arrived from the streaming server. This
directly contrasts with a static model of data delivery, where all the data is delivered
to the client machine prior to actual playback. If used properly, streaming
applications can add impressive capability to any site.
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CONTENTS
CHAPTER PAGE NO.
1. INTRODUCTION 03-04
2. USTREAM 05-06
3. VIDEO STREAMING 07-09
4. VIDEO STREAMING ARCHITECTURE 10-12
5. STREAMING REQUIREMENTS 14-15
6. USTREAM PROTOCOLS 16-18
7. CONSTRAINTS OF VIDEO STREAMING 19-22
8. APPLICATIONS OF USTREAM 23-24
9. ADVANTAGES AND DISADVANTAGES 25-27
10. CONCLUSION 28
11. REFERENCES 29
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CHAPTER 1
INTRODUCTION
Video has been an important media for communications and entertainment for many
decades. Movie is a form of entertainment that enacts a story by screening a series
of images giving the delusion of continuous movement. The trick was already known
in second-century China, but remained inquisitiveness up to the end of the 19th
century. The invention of motion picture camera around 1888 allowed the individual
component images to be captured and stored on a single reel. For the first time, this
has made possible the process of recording scenes in an automatic manner. Further
to that, a hasty transformation occurred with the development of a motion picture
projector to enlarge these moving picture shows onto a screen for an entire audience.
Television broadcasting after its invention in 1928 has attracted billions of people
from different part of the world to watch both live events and recorded videos
simultaneously through their television sets. People moved from newspaper and
radio to the more immersive experience of television as their primary source of
entertainment and as a way to receive important information and news about the
world. For most of the twentieth century, the only ways to watch television were
through over-the-air broadcasts and cable signals.
A third boost in the popularity of moving pictures came at the end of the 20th century
with the invention of the Internet and of the World Wide Web. Web browsing and
file transfer are the dominant services provided through the Internet. However, these
kinds of service providing information about text, pictures and document exchange
are no longer satisfied the demand of clients. Following the success of conventional
radio and television broadcasting, research has been carried out into ways of
delivering live media over the Internet to a personal computer. As a result, people
have experimented with transmitting various multimedia data such as sound and
video over the Internet. All multimedia content were distributed no differently than
any other ordinary files such as text files and executable files. They were all
transmitted as ―files using file downloading protocols such as ftp and http. The full
file transfer, in the download mode, can often suffer unacceptably long transfer
times, which depend on the size of the media file and the bandwidth of the transport
channel. For example, if downloaded from http://www.mp3.com, an MP3 audio file
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encoded at 128 Kbit/s and of 5 minutes duration will occupy 4.8 MB of the user‘s
hard disk. Using a 28.8k dial-up modem, it would take roughly 40 minutes to
download the whole file.
As a result, an audio file might take more real-time to download than the length of
the audio being played. Video, which carries much more information than audio,
entailed even longer download times. Furthermore, there was no way for the users
to ―peek into the content to see if it is the video they would like to watch. This was
often inconvenient for the users due to a long waiting time and a large amount of
wasted resources when the content of the video turned out to be something they were
not interested in. Thus, a new technology was needed to meet the user demands of
high speed data transmission. This gave rise to live streaming technologies.
Streaming video is one way to deliver video over the Internet. Though far from a
perfect solution, streaming video technology is becoming more powerful all the
time. With streaming video, designers can broadcast lectures, make announcements,
deliver seminars, or show exactly how something is supposed to work. And users
can see it now, quenching some of their thirst for fast, high-quality video. Streaming
video provides flexibility as well.
USTREAM is one such live streaming technology where users can watch while
event is happening OR after event has ended if owner of channel keeps previously
recorded videos uploaded. USTREAM technology is fashioned on a client-server
model. Users can view what they want, when they want. Streaming video offers
many opportunities to the web designer, and to make the best use of this technology,
designers need to understand what it is, how it works, and the advantages and
disadvantages of using streaming video.
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CHAPTER 2
USTREAM
Ustream is a website that allows members to broadcast live streaming video on the
Internet. USTREAM is a live streaming website where users can watch while event
is happening OR after event has ended if owner of channel keeps previously recorded
videos uploaded. USTREAM technology is fashioned on a client-server model.
Users can view what they want, when they want.
Ustream was established in March 2007. Ustream was initially conceived as a way
to connect soldiers overseas with their families back home. Ustream started with
U.S. Army Officers John Ham and Brad Hunstable who wanted to provide a new
way for deployed soldiers to communicate with their families. Before Ustream,
soldiers could only use a telephone or instant messenger to talk with their loved ones,
limiting their contact to only one person at a time. Officers Ham and Hunstable
partnered with Dr. Gyula Feher, and in the summer of 2006, they released Ustream,
a "live, interactive video broadcast platform" that allowed soldiers to communicate
with friends and family simultaneously across the globe. Founders felt that a product
like Ustream would provide soldiers with a way to talk to all of their relatives
simultaneously during their limited free time in the war zone.
Ustream is composed of different feeds that enable lifecasting and streaming of
videos of events online. Members can broadcast directly from the Ustream website
or from a mobile device using Ustream's mobile broadcasting application (available
for Android and iPhone). Ustream members can also record and save videos for
future broadcast distribution. Ustream's video platform is known for its ability to
provide viewers with different ways to interact with the presenter during a live
broadcast, providing broadcasters with chat and instant polling features, as well as
allowing integration with Twitter and Facebook news feeds.
The idea is pretty simple: Provide a common area for a person to broadcast him or
herself and allow the broadcaster and viewers to communicate instantaneously.
According to the Ustream Web site, it allows "anyone with a camera and an Internet
connection to quickly and easily broadcast to a global audience of unlimited size."
To overcome these constraints we have certain mechanisms.
1. Overcoming the Bandwidth Problem:
Rate Control
1. Estimate the available bandwidth
2. Match video rate to available bandwidth
Rate control may be performed at:
Sender
Receiver
Available bandwidth may be estimated by:
Probe-based methods
Model-based (equation-based) methods
Source-based rate control:
Source explicitly adapts the video rate.
Feedback from the receiver is used to estimate the available bandwidth.
Feedback information includes packet loss rate.
Probe-based methods:
Uses probing experiments to estimate the available bandwidth
Adapt sending rate to keep packet loss rate ρ less than a threshold Pth
If (ρ< Pth) then increase transmission rate
If (ρ> Pth) then decrease transmission rate
Different strategies exist for adapting transmission rate
Simple, ad-hoc
Model-based (equation-based) methods: Ensure fair competition with concurrent TCP flows on the network, e.g. fair sharing
of bandwidth.
Model the average throughput of a TCP flow.
Transmit video with the same throughput as if it was a TCP flow.
Similar characteristics to TCP flow on macroscopic.
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Receiver-Based Rate Control: Receiver explicitly selects the video rate from a number of possible rates Sender codes video with scalable or layered coder
Sends different layers over different multicast groups
Each receiver estimates its bandwidth and joins an appropriate number of
multicast groups
Receives an appropriate number of layers up to its available bandwidth
2. Overcoming Delay Jitter: Playout Buffer
The main technique is to add a buffer at decoder to compensate for jitter.
Corresponds to adding an offset to the playout time of each packet.
If (packet delay < offset) then OK
It allows Buffer packet until its playout time
If (packet delay > offset) then problem
Playout buffer time are typically 5-15 secs. The buffer Compensates for delay jitter
and enables retransmission of lost packets.
3. Overcoming Loss:
Error Control
Error control method is used to overcome the effect of errors such as packet
loss on a packet network or bit or burst errors on a wireless link.
Types of Error control are:
Forward Error Correction (FEC)
Retransmission
Error concealment
Error-resilient video coding
They add specialized redundancy that can be used to recover from errors.
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CHAPTER 8
APPLICATION OF USTREAM
Ustream provides numerous notable applications. However, the most important
application is Event Broadcasting. The major applications of Ustream are:
Video Conferences
Event broadcasting
Online TV
Trainings
Advertisements
Rising trend in USTREAM viewers
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One of the most popular application of Ustream is live streaming of wedding
functions. Marriage live streaming trend is on the rise among various countries of
the world. Many prefer to live stream the Wedding reception. This is contributing to
the increase in the average live streaming time per wedding. More and more guests
are watching the wedding online. In India, on an average 32 guest watched wedding
online in 2011, which increased to 44 in 2012 and 46 in 2013.
Wedding live streaming viewer distribution
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CHAPTER 9
ADVANTAGES AND DISADVANTAGES
ADVANTAGES:
Instant play In the early days of the Internet, if a webmaster wanted to add videos to his
website he had to post it as a link. Web site visitors then had to download the
file completely before playing it back. This all changed with streaming video.
Content is served in a way that allows files to play almost immediately after
the file begins to download. Special streaming media servers also allow
viewers to jump forward and backward through a video file. The end-user can
decide whether she wishes to view the entire video, without having to endure
a long download before she can decide. For the host site, the quick start tends
to keep end-users on the site and interacting, increasing the chances that the
user will click on a related link or an advertisement.
Content Security- no local copy is saved Allowing your Web site visitors to download video files -- especially
copyrighted material -- makes it much easier for your content to be pirated.
Your downloaded video files could be shared with others through file-sharing
networks and other methods. Streaming video technology is harder to copy
and prevents users from saving a copy to their computer if you don't want
them to. While it's not perfect, it may give you better peace of mind about
distributing your content online.
Reduced costs Think of all the costs associated with travelling, lodging, venues, meals, and
more that add up when creating a traditional event. Most of these costs can
now be eliminated through the power of web streaming. The cost of web
streaming is also potentially less than those associated with satellite radio
subscriptions and buying CDs.
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Wider audiences Through webcasting, you have the potential to reach anyone remotely; all a
participant needs is access to the Internet. The biggest benefit is that you can
dramatically widen access to information and events. For training employees
or sub-contractors, everyone can receive the same training and information at
the same time - which also ensures consistency. For a product launch, media
and other constituents will all get to see the release at the same time.
Convenience On demand programming can be listened to in the comfort of your home or
office. In addition, presenters/instructors can deliver from anywhere.
Richer content There is a wide variety of content to choose from. With webcasting, you have
the flexibility of combining various presentation methodologies and
multimedia. You even have the option of recording great videos for use
indefinitely.
Broadcasting range Webcasting provides for unlimited range in broadcasting whereas radio, for
example, has limited signal strength.
Quality of output Webcasting provides for good quality audio and video broadcasts.
DISADVANTAGES:
Bandwidth Bandwidth availability is a key problem in the delivery of streaming video. If
the sender overestimates or underestimates the available bandwidth, the video
quality will suffer. Errors in bandwidth estimation lead to loss of packet or
delays in packet delivery, which can cause degraded video quality or jerky
video playback. While various error control methods, such as buffering, can
limit these problems, no solution completely eliminates them.
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Online Only While the advantage of giving your users instant playback and yourself
protection from content pirates might be attractive, these can also work
against you as streaming video works only when there is an available Internet
connection. If the viewer's Internet connection is cut during playback or they
need to watch your content offline, they will be out of luck. In these cases
consider offering the user an option to both stream and download the video
file, and using copy protection to prevent piracy.
Cost Costs mount quickly with live streaming video. Expensive camera equipment
and high-end computer equipment are needed to transmit the feed. In addition,
securing enough bandwidth to support a live broadcast typically requires the
services of an Internet service provider (ISP). While potentially less expensive
than managing the entire process in-house, the costs for bandwidth usage can
still run high.
Accessibility
Streaming video content poses two different challenges in terms of
accessibility. The first is that people who are hearing impaired cannot take full
advantage of your content if you do not add captions. The second issue, which
has much broader impact, is that anyone in a place where his computer can’t
make noise can’t fully experience your video, either. This can be problematic
in an office that needs to be quiet, or when someone is using his smartphone
without ear buds on public transportation. While captions can help with this
issue to some extent and can also improve your SEO, they're far from a perfect
solution.
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CHAPTER 10
CONCLUSION
Streaming distribution systems can be used to broadcast video live or repeat. In any
case, when carrying out a distribution of contents via streaming we must remember
at all times that most final users who access the internet are generally restricted to
2Mbps. However, the generalization of cable access and ADSL is increasing
bandwidth from 128kb/s to 512kb/s for a growing number of individuals. In the cases
of higher bandwidth we can obtain video of a quality very similar to VHS, thanks to
the latest compression techniques and sophisticated codec’s technologies.
Besides bandwidth, other issues are important when distributing audio visual
material via streaming. The first one is content creation, which has to bear in mind
at all times the compression that will be suffered by the video being produced.
Because after compression the size of video images is likely to be smaller, certain
visual information will be inevitably lost. In order to minimize this loss it is
important for the content creator to ensure that the lightening throughout the video
is good, the backgrounds are plain, camera movements are limited and close-ups are
clear and plentiful.
A second issue that must be considered is the streaming server, which sends media
clips to users. Real time streaming requires specific servers. As we have seen, Real
Networks, Microsoft and Apple have streaming servers. The role of the client and
user is also important. Ideally, users must be presented with a simple interface
requiring little more than a click to download or update streaming reproduction
software. In reality, however, users often have to face huge files and complex
procedures with many more options than it is strictly necessary. The good news is
that this situation is progressively changing, and improvements are being made in
this respect.
We have seen that streaming allows the distribution of audio visual content to large
audiences in a simple way over the internet. However, as a technology in constant
evolution, it still has some limitations. To maximize its current potential, all parties
(from content creators to clients and users) must be aware of them and act
consistently.
In spite of a few problems, the advantages offered by streaming in comparison to
traditional content distribution methods are many. Given that video is increasingly
incorporated into websites, and information exchange technology is constantly
evolving, it is expected that internet streaming will soon be present everywhere. The
next step will be to improve the way video is presented on the internet, to ensure that
audio visual content interesti
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CHAPTER 11
REFERENCES
en.wikipedia.org/ustream
www.ustream.tv
www.free-video-hosting.net/embed.php
The technology of video streaming – David Austerberry