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Compression Technology

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image CHAPTER OVERVIEW

Unit 11.1 Evolution of the internet
Unit 11.2 Big data concepts
Unit 11.3 Multimedia as part of internet technologies
Unit 11.4 Compression technology

image Learning outcomes

At the end of this chapter you should be able to:

  • describe the evolution of the internet in terms of software and applications
  • explain the differences between downloading, streaming and live streaming
  • describe the role of multimedia on the internet
  • explain how multimedia compression technology works

INTRODUCTION

The internet has not just changed the way we work or find information, it has also changed the way we are entertained. One of the clearest examples of this can be seen in the development and incredible growth of eSports. eSports is a general term that refers to computer games being played professionally. Thanks to the internet, eSports has become a massive spectator sport with thousands of professional eSports athletes and millions of viewers per day.

This incredible growth is only possible because of the internet and internet technologies, including:

  • internet applications
  • video streaming and live streaming
  • multimedia compression.

In this chapter, you will learn more about these technologies and how they have changed the way people live.

Activity 11.1 Revision activity

11.1.1Give ONE word/term for each of the following descriptions. Write only the word/term next to the question number.

a.The composing, sending and receiving of messages electronically over a network, including the internet.

b.The part of the internet where websites like Facebook and Google can be found.

c.Each computer on the internet has a unique internet address.

d.To make it easier to find a specific computer on a network, a person or company can purchase a this for themselves.

e.A device that is used in a wired network to connect the LAN to the internet.

11.1.2To make sure everything is covered for the gala, regular meetings with the committee is important. The best way for them to stay connected is through the internet.

a.There is some confusion between the terms internet and World Wide Web (WWW). Distinguish between these two terms by describing both.

b.Name the protocol used for sending e-mail via the internet.

c.List ANY two devices required to connect to the internet using a 4G connection.

UNIT
11.1 Evolution of the internet

In Grade 10, you learned that the world-wide web (or WWW) is the part of the internet where websites like Facebook and Google can be found, while the internet is the network connecting computers all over the world. Each computer on the internet has a unique internet (or IP) address. For example, if you have an IPv4 address, your computer’s IP address might be: 102.250.56.11

Each number can range from 0 to 255 and can be represented by 1 byte (or 8 bits) of information. To make it easier to find a specific computer on a network, a person or company can purchase a domain for themselves that is linked to their IP address. Any person entering the name of their domain (for example, google. com) in a web browser will then automatically be taken to the linked IP address

The world wide web changes almost as frequently as fashion changes. Every year, websites rush to be the first to adopt the newest web development trends, styles and best practices.

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Figure 11.1: YouTube in 2006 compared to YouTube in 2018

More than simply the way the internet looks, the way we use the internet has changed dramatically in last 20 years. The most significant of these changes are captured using the names Web 1.0, Web 2.0 and Web 3.0

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Did you know

If you want to see what a website looked like a long time ago, you can visit the Wayback Machine at https://archive.org/web/ and enter the name of your favourite website.

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QR CODE

WEB 1.0

When the internet was first launched, websites were created specifically to provide information to users. As a result, the only information you could find on the internet was information that a web developer or content developer had specifically placed there.

Web pages from that era were static pages with all the information programmed directly onto the web page. As a result, these web pages stayed the same way until a web developer changed the web page’s code. Web pages from that era were also not interactive, so once a user landed on a web page, the only thing they could do was read the information and look at the pictures.

The figure below shows an example of a Web 1.0 web page.

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Figure 11.2: Marshall Brain’s personal web page is a Web 1.0 page

WEB 2.0

Once sites like Google, MySpace and later YouTube, Twitter and Facebook started appearing, the internet had changed. Websites became interactive and dynamic. Instead of simply providing information, websites became applications that allowed users to search, send messages, post updates and watch videos.

With Web 2.0, users play a role in the development of content, whether through posting a status update on Facebook, uploading a video on YouTube, or writing an article for Wikipedia. Using this model, Wikipedia has become the world’s largest encyclopaedia with articles on 6 million different topics in more than 100 languages. Every month, 120 000 Wikipedia visitors from around the world update existing articles or write new articles.

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Figure 11.3: Wikipedia is an example of a Web 2.0 website

With Web 2.0, web developers have a different role. Rather than creating all the content, web developers are responsible for creating a platform (or application) that users can interact with. Users can then create and upload their own content.

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Did you know

Every second, YouTube visitors upload 5 hours of new videos to YouTube.

WEB 3.0

Web 3.0 is like Web 2.0, but smarter! In the last 15 years, the internet has grown (and continues to grow) faster than anyone expected. While more information is usually a good thing, it also means that good or relevant information becomes more and more difficult to find. To solve this problem, internet services are creating increasingly smarter web applications to help find and recommend relevant information to visitors.

Web 3.0 will be able to get the context from the user; and then be able to provide the user with the most useful information. Web 3.0 can be likened to an artificial intelligence assistant that understands its user and personalizes everything.
For example, if someone is preparing for a vacation and needs to search for cheap flights and accommodations, they have to look through a lot of information on the web and compare different options and the search might take hours. Web 3.0 search engines or assistants will be able to gather all of this information and present it to the user in a very intelligent way and even make highly accurate and favorable suggestions.

INTERNET OF THINGS (IOT) (CHARACTERISTICS AND USES)

The Internet of Things is the network of physical devices that are embedded with electronics, software, sensors, actuators, and connectivity, which enables these devices to connect and exchange data. This creates opportunities for more direct integration of the physical world into computer-based systems. IoT results in efficiency improvements, economic benefits, and reduced human effort.

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Did you know

In 2017, the video streaming website Netflix offered a $1 000 000 prize to anyone who could improve their movie and television series recommendation algorithm. A team called Pragmatic Chaos won the prize by writing an algorithm that was 10% better than Netflix’s own algorithm.

Examples include:

  • Connected security system where you are able to turn on and off the lights in your house through a smartphone app. You can also open your electronic gate and watch video cameras placed around your property.
  • Household appliances, can be operated, for example, by using an app on your smartphone. Here are some examples.
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Figure 11.4: Applications that can control different appliances in your home
  • Connected cars – a car that can communicate bi-directionally with other systems outside of the car (LAN). This allows the car to share internet access, and therefore data, with other devices both inside and outside the vehicle. In the near future cars will be able communicate with each other for safety-critical applications.

image Case Study Internet applications

One of the biggest developments on the internet has been the rise of web applications. These are websites that, rather than providing information, work like desktop applications. Thanks to the growth of these applications, the distinction between websites, web applications and desktop applications have become incredibly thin.

Popular web applications include:

  • Office 365: Microsoft Office, with all the typical features, available from a web page.
  • Google Drive: Google’s free-to-use office suite and online backup application.
  • Gmail: Google’s online email client is the most popular email client in the world.
  • Messenger: Facebook’s online instant messaging service.
  • Trello: An online project management application used by many businesses.
  • Sketchpad: An online drawing application and sketching application.

In 2015, Google announced that Assassin’s Creed Odyssey, the newest game in Ubisoft’s incredibly popular series of action role-playing games, would be playable through the Google Chrome web browser. As one of the most graphically demanding games available in 2018, this will continue to make the distinction between an application and a web application even smaller.

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image Activity 11.2

11.2.1Match the COLUMN A with the correct answer in COLUMN B. Write down only the question number (1.1–1.6) and the matching letter (A–F) in COLUMN B, for example 1.1-A.

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11.2.7Having the world at your fingertips through internet so commonly used nowadays, you and your cousin decides to take your entrepreneur business to the next level. To get your business out there, you realised you need a website. Soon you face the challenge between choosing between Web 1.0 versus Web 2.0.

a.Define a website.

b.Explain the difference between these two web versions by listing TWO characteristics of each.

c.Give TWO examples of a Web 3.0 application.

11.2.8Optional activity
Visit the following websites and state (with reasons) which type of website it is, i.e. Web 1.0, Web 2.0 or Web 3.0.

a.www.hatch.com

b.www.virginactive.co.za

c.www.standardbank.co.za

d.https://twitter.com/

UNIT
11.2 Big data concepts

Big data isn’t easy to define because everyone uses it differently. However, big data generally is:

  • large datasets
  • the category of computing strategies and technologies that are used to handle large datasets.

It is the non-traditional strategies and technologies needed to gather, organise, process, and gather insights from large datasets. We have looked at the relationship between data, information, knowledge and decision-making. If the quantity of data is so vast and there are not correct strategies of extrapolating knowledge then decision-making cannot happen and the company will fail. Dealing with data is thus very important.

There are four characteristics of big data. These are listed in the table below:

Table 11.1: Characteristics of big data

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There are many different uses for big data but we will look at three, namely:

  • Customer profiling: by using big data, you can gain an insight into your customers. Businesses can gain a comprehensive and data-based description of a customer that includes variables such as demographics, and consumption patterns. These patterns give you insights as to who your customers are, what they want and what they need, allowing you to connect with your customers in a way that appeals to their interests.
  • Advanced patient care: In the past, nurses and doctors monitored patients’ physical vital signs every few hours but a patient’s condition may have declined between the time of scheduled visits. Or if a patient has been discharged, there is no way to monitor their progress, if they skip their medications or ignore dietary and self-care instructions given by their doctor after leaving the hospital.
       Real-time monitoring and body sensors provide a more personalised treatment to enhance patient outcomes. This has the potential to lower costs of hospital care as less attention is needed by a nurse, because a computer can analyse the big data. Wireless sensors can capture and transmit patient vitals far more frequently than human beings can visit the bedside, and these measurements can be analysed in real time for advanced care. Diagnosis times are shortened and treatments are prescribed quicker.
  • The agricultural sector has benefited from big data in many ways. Sensors on fields and crops provide data on the soil conditions, wind direction and speed, fertiliser requirements, water availability and pest infestations. Farm equipment like tractors are equipped with GPS units to find their optimal usage. Analysis of big data can also help prevent spoilage by moving products faster and more efficiently. Drones can patrol fields to alert farmers to crop ripeness or potential problems. RFID-based traceability systems can provide a constant data stream on farm products as they move through the supply chain, from the farm to the compost or recycle bin. Individual plants can be monitored for nutrients and growth rates.

image Activity 11.3

In small groups research other uses for big data. Share your findings with the class.

UNIT
11.3 Multimedia as part of internet technologies

Multimedia plays a big role in the internet’s popularity. Thanks to multimedia, billions of people have access to high quality books, music and videos at affordable costs. For many people today, internet access has replaced expensive items such as movie rentals and satellite television subscriptions. To see how multimedia on the internet has changed the world, you can look at three of the world’s largest multimedia websites: YouTube, Netflix and Spotify.

These websites are considered streaming websites, which refer to the way in which the media is sent to users. In the next section, you will learn more about the difference between downloading, streaming, live streaming and video-on demand services. You will also learn a bit more about multimedia compression and how this affects both bandwidth usage and video quality.

DOWNLOADING AND STREAMING

It is possible to listen to music or watch videos from the internet in two different ways:

  • media can be downloaded to your computer and played from your hard drive
  • media can be streamed directly from the internet and played in your web browser.

DOWNLOADING

Downloading is the easiest way to share media on the internet. The media owner can simply upload the file to their website and then share a link to that file with website visitors. To play an item shared like this:

1.open the website in your web browser

2.download the media file to a location on your hard drive

3.open the media file on your hard drive using any installed media player.

Since the media file has been saved to your hard drive, you can play it as many times as you like (even without an internet connection).

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Figure 11.5: Downloaded media like movies can be played using a media player

For online media companies, the problem with sharing media like this is that it is difficult for the companies to make money from the video. Once the video has been downloaded, it can be shared with hundreds or thousands of people without the video creator earning any additional money. As a result, there are currently almost no popular media websites that allow their videos or music to be downloaded.

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Did you know

The few streaming services that allow videos or music to be downloaded (like iTunes) use digital rights management (or DRM) to ensure that the music cannot be copied to a different computer once it has been downloaded.

image Case Study Video On-Demand

The one type of service that still allows videos to be downloaded are IPTV (short for Internet Protocol Television) services like DSTV’s Catch-up. These services are usually sold as an optional extra with an expensive satellite television contract and allow you to watch episodes or movies that you missed later (or ‘on demand’).

Since the videos are not downloaded to a desktop computer but rather to a satellite television decoder, IPTV service providers are not worried that these files will be shared with thousands of people. Furthermore, since each subscriber already pays a significant monthly subscription fee to the IPTV service provider, the IPTV service is simply a marketing tool they use to sell more satellite television subscriptions.

STREAMING

Since downloaded media is difficult to monetise, most large online multimedia companies share their media through streaming. To play streaming media:

1.open the website in your web browser

2.open the media file in your web browser

3.the media file should start playing automatically.

With media streaming you never save the media file to your hard drive. Instead, the moment you click the play button on the website, your computer downloads a few seconds of the media in the background and shows it to you. As you play these downloaded seconds, your computer downloads the next few seconds. This is called buffering and your computer continues to buffer and play the media until you reach the end of the item.

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Figure 11.6: The buffered section of the video is indicated by light grey line below the video

When you then close your browser, all these buffered seconds are deleted from your computer. As a result, you will need to stream the video again the next time you want to watch it.

For online media companies, the advantage of this system is that they can show advertisements before or during the item. As a result, each time you or your friends stream it, the media company makes a small amount of money. Therefore, websites like YouTube, Netflix and Spotify only allow their videos and music to be streamed.

Before finishing this unit on media streaming, there are two specific types of streaming websites you should also be aware of:

  • live streaming websites: As the name suggests, live streaming websites like Twitch.tv allow ‘live’ videos to be streamed. These videos show a live broadcast of something happening, whether it is a game being played, a music concert or a sporting event.
  • video on demand websites: Video on demand (VOD) websites, like Netflix and Showmax, allow you to watch broadcast television shows and events ‘on demand’. Unlike YouTube and Facebook that allow anyone to upload videos, VOD service providers are more like satellite television providers in that they specialise in high-quality, professionally produced television series and movies. Unlike with television, you can watch these episodes and movies whenever you want to.

For videos that are watched only once, there are no differences between downloading and streaming in the amount of data and bandwidth used. The only difference is whether the data is saved on your computer (as with downloading) or displayed and deleted (as with streaming). However, when a video is watched more than once, the downloaded file will not use any additional data (since it is already saved on your hard drive), while the streamed file will need to be streamed again, using the same amount of data as the first time. As such, downloading videos will save data if the video will be watched more than once. Fortunately, thanks to media compression (which you will learn about next), these streamed media files do not require as much bandwidth as they used to.

image Activity 11.4

11.4.1One of the reasons to connect the devices to the internet is watching online television programs. You can either stream or download the programs. Differentiate between streaming and downloading

11.4.2List TWO ways you can listen to music using the internet.

11.4.3Discuss why there aren’t any popular sites that allow music or video to be downloaded freely.

11.4.4One of your clients has indicated that he might need your services since they are planning to go into partnership with a popular Internet Protocol TV (IPTV) company which also offers VOD services.

a.What is the internet?

b.Differentiate between IPTV and VOD services. Indicate where each one may be used.

11.4.5The following advertisements were placed on advertising boards outside the administrative building:

a.What is a Wi-Fi?

b.Advertisement C suggests that streaming can take place live online. Explain the term streaming.

c.List TWO ways you can download a music video using the internet.

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UNIT
11.4 Compression technology

Streaming or downloading media, especially videos, from the internet can require a lot of bandwidth and use a significant portion of your bandwidth limit. To give you an idea, the table below shows a rough estimate of how much data different internet activities use per hour.

Table 11.2: Estimate of data used per hour

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Take note that this is for a single person. If four people watch an average of two hours of high quality videos per day, they will use 240 Gb in a month!

High quality videos differ from low quality videos in two important ways:

  • High quality videos have a higher resolution
  • High quality videos may have a higher frame rate

The resolution of a video refers to the number of pixels shown on the screen at any time. Every pixel is a single dot of a specific colour (recorded as a mixture of red, green and blue). It is the most basic unit of colour and resolution. When creating a digital video, every part of the picture is converted into pixels. The more pixels that are used, the higher the quality of the image. The figure below shows the letter R at seven different resolutions. With anything less than 100 pixels (10 × 10), it is completely impossible to see what is being shown, and the image only becomes clear at 2 500 pixels (50 × 50).

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Figure 11.7: The higher the pixel count, the better the image quality

Video compression allows video streaming sites to dramatically decrease the size of videos without significantly decreasing the quality of the videos. As a result, 1 second of raw video uses the same amount of data as a 10-minute compressed video (like an WebM or MP4 video) with the same resolution and frame rate!

After a file has been compressed, it is saved in a compressed file format. The table below lists and describes a few of the most popular compressed file formats.

Table 11.3: Compressed file le formats

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Regardless of the type of compression used, a compromise must always be made between the quality of the final image, audio or video file and the size of the file. The more a file is compressed, the smaller the file becomes but the worse its quality becomes. This means that compressed files require less bandwidth to stream and can be downloaded more quickly, but they may not look as good as uncompressed files. The goal for most websites is therefore to find a compression algorithm and compression level that allows the files to be streamed smoothly without noticeably decreasing the quality of the files.

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Did you know

All compression is a trade-off between file size, quality, and the processing power required to decompress the media in a reasonable time.

image Activity 11.5

11.5.1The following statements are either true or false. State whether each statement is True or False. Correct each of the false statements by rewriting the statement to make it true. In other words, replace the bold-printed, underlined portions with the correct term.

a.The resolution of a video refers to the number of pixels shown on the screen at any time.

b.The less a file is compressed, the smaller the file becomes but the worse its quality becomes.

c.The more pixels that are used, the higher the quality of the image.

d.Each pixel is represented by 3 bytes of data this is 1 byte for each colour.

e.Video compression artefacts can save a lot of space by only recording the pixels that change noticeably from one frame to the next.

11.5.2The Dance Society at the school needs to share a video of their dancing competition amongst each other. They are suggesting that you compress the file for better quality.

a.Mention the main disadvantage of media compression.

b.It is suggested that you compress the file using JPEG format. Indicate why this is not possible and provide an appropriate compression format.

c.Discuss how compressing a file affects the quality of the file.

11.5.3Why won’t YouTube allow you to freely download Netflix videos to watch?

11.5.4What is the difference between a live-streaming website and a video-on-demand website?

11.5.5How do high quality videos differ from low quality videos? Explain this in your own words, referring to the resolution and frame rate.

11.5.6How does video compression work?

a.Explain the purpose of video compression.

b.What is an example of a compressed image file?

CONSOLIDATION ACTIVITY Chapter 11: Internet and www

1.Complete the software comparison table.

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2.Define big data by completing the mind map.

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3.In your own words explain the following:

a.Download vs streaming multimedia:

b.Live broadcasts

c.Video on-demand

4.What is compression technology and how does it affect media?