BLO1105 Business Law | Apple HTTP Live Streaming

Introduction

Streaming audio and video is a relatively new phenomenon in the field of information technology, having first appeared in the early 1990s. This web based technology was developed to meet the demands of information distribution in an increasingly connected world. According to  Digital in 2017 Global Overview report [1], more than half of the globe uses the internet.  Streaming has enabled people to interact in a very powerful way. Company executives can comfortably hold a meeting regardless of where each one is, students can interact and learn with their lecturers and tutors at the click of a button and generally anyone who wants to interact with any other person simply has to use one of the many streaming tools available on the internet. All that is required is an internet connection and a web camera. Currently, there is ongoing research in the area of streaming as various companies, such as Google, CloudFront and YouNow struggle to have a considerable share of the market.

Underlying mechanism of streaming

In streaming, audio/video content sent in compressed form over the internet and displayed by the viewer in real time. The user does not have to download the content first to play it, instead it is played as data arrives.

The user sends a request to the web server for the content they want to view or listen. The web server then sends a request to the streaming media server for the specific file. The streaming media server then streams the content data to user. It bypasses the web server while doing so.

Video and audio data have to compressed, encoded, transmitted then decoded and decompressed for viewing/listening. Encoding and decoding is done through codecs.

Content can also be distributed to many simultaneous viewers in what is known as web casting, thanks to the multiuser environment of the web. Alternatively each client can take a separate stream from the server in what is known as unicasting. In unicasting, all users viewing the same content from the same server have to establish separate connections.

Traditionally, plugins, such as flash player, were used in incorporating video and audio elements in a web page. With the recent advances in HTML5, videos and audio can now be embedded in the web page. HTML5 has an advantage of being compatible with mobile devices while the flash player does not.

Types of streaming include:-

• File download
• Progressive download
• Real time streaming protocol- a network control protocol designed to control streaming media servers.
• Adaptive HTTP streaming

The following is the schema for a cloud based streaming architecture:

Middleware

Middleware exists to support the interaction of distributed systems through a software infrastructure. Interactions between software components are divided into two categories, which are discrete and continuous [2]. Discrete interactions utilize Remote Procedure Calls or messages which are used to invoke a computational service. On the other hand, continuous interactions are used for exchanging multimedia data which are known as.  Examples of middle ware include CORBA, DCOM and Java RMI.

The overall objective of middleware is to simplify access to and operation of multimedia equipment and services from any host in the internet [3]

Corbe

CORBA stands for Common Object Request Broker Architecture and is a standard developed by the Object Management Group (OMG) to enable interoperability among network objects in a distributed environment. The reason behind this was that networks, more so the internet, have varied hardware and software platforms which need to communicate with each other. Currently, there are 42 million devices connected to the internet [4].

Dcom

DCOM stands for Distributed Component Object Model and is a technology developed by Microsoft for the communication of software components in a network environment. It is a client/server protocol that provides distributed capabilities to the earlier COM model for Microsoft workstations [5].

Java RMI

Java RMI (Remote Method Invocation) is the Java standard API for the creation of applications which will run in a distributed environment. Implements object oriented programming in the distributed environment for the Java platform. Due to the characteristics of platform independence and portability of Java, Java RMI is an appropriate technology to implement middleware layer providing seamless service availability throughout heterogeneous system [6].

Protocols used in a cloud

Real time Transport Protocol (RTP)

It's a protocol which operates at the transport layer of the TCP/IP protocol and is designed specifically for real-time transfers. It is connected with the UDP part of the transport layer, although it can also work at the TCP part [7].

Real Time Messaging protocol (RTMP)

The RTMP is a protocol which also operates at the transport layer of the TCP/IP protocol. It was developed by Macromedia for streaming audio and video over the Internet, between a Flash player and a server.

Real time Control Protocol (RTCP)

This protocol works at the session layer of the TCP/IP protocol. Its basic role is to provide feedback on the quality of the data distribution, for example, the data rate.

The Real Time Streaming Protocol (RTSP)

This protocol works at the presentation layer of the TCP/IP protocol. Its primary function is to carry requests to the streaming media server to initiate actions such as play, stop, pause and record.

Apple HTTP Live Streaming (HLS)

The Apple HLS operates over HTTP and supports the adaptive bit rate technique, to not only achieve reliable delivery but to ensure smooth streaming. The adaptive bit rate technique manages performance of streamed media over distributed computer networks [8].

Microsoft’s Smooth streaming

This is Microsoft’s IIS Media Services extension, which also uses the adaptive bit rate technique in streaming of media to Silverlight and other clients over HTTP in distributed networks.

Adobe HTTP Dynamic Streaming (HDS)

It is also known as the San Jose streaming and operates over HTTP by implementing the adaptive bit rate technique. It works with the flash media player and is mainly used in desktop environments.

BitTorrent Live Streaming

It is a peer-to-peer protocol that can scale to very large numbers of users where each user is capable of broadcasting to other users across the Web.

Htl5

This is an application-layer protocol only that allows JavaScript to control the playing of audio and video content in a web page [9]. The content is downloaded progressively, and will keep downloading even if the user pauses the media.

Tools available on the net for streaming

Google Hangouts on Air

It is one of the most popular tools to use for group video chats and can accommodate up to 10 participants. It is free to use and allows users to broadcast video e to a larger audience on Google+, YouTube or their own website. Broadcasters can also take questions and interact in real time with their audience.

YouTube Live Events

This is found on the YouTube site and is mostly used for broadcasting live video rather than videoconferencing. It is also free.

YouNow

This is similar to YouTube Live events and also provides the capability of streaming live videos to viewers and subscribers.

Tinychat

This is an online video chat community that is used mostly for casual chatting purposes. You can set up your own video chat room in any category or topic and invite other users to join, or alternatively join an existing one to view and chat.

Metrics that are related to performance of audio and video transfer and sharing

1. Bit Rate

Bit rate indicates how many bits of video/audio can be transmitted over a given period of time. The bits are usually represented in terms of how many Megabits can be transmitted in a second, hence Megabits per second (Mbps). Bit rate helps in understanding the quality of the video/audio that is being transmitted. It is directly proportional to quality of the video/audio. That means that the higher the average bit rate the higher the audio/video quality. Standard definition television is typically transmitted at a bit rate of 3.5 Mbps, while HDTV can be range from 8 to 15 Mbps. Netflix Super HD streams at approximately 6 Mbps.

2. Buffer Fill

This is the time spent filling in the buffer when the video is requested by the user. This helps in knowing how long the user is waiting before a video actually starts playing. The familiar rotating circle indicates that the video is buffering and the longer it takes, the more likely the user will abort.

3. Lag Length

This is the sum totals of the initial time that the user waits for the buffer to fill up and any playback halts that occur when watching. Playback halts occur when the download rate cannot keep up with the bit rate. It is an important metric for understanding the viewer’s experience.

4. Play Length

The total amount of time in seconds, minutes, and hours that has been taken by a user to stream data out of a datacenter. It goes hand in hand with the amount of data consumed. This metric is important to understand for capacity and infrastructure planning. It also helps in estimating peak data volumes and overall demand for streamed data.

5. Lag Ratio

This is the ratio of waiting time to watching time. An increasingly small ratio means that delivery is of high quality.

The usefulness of streaming

According to a study by Reed [7] for the Academic Journal, students who received instruction through a video streaming application showed dramatic improvement in their academic achievement. The study further found that when students in three Virginia school districts were exposed to the streaming application, they showed an average increase of 12.6% in performance as compared to students who received traditional instruction alone.  Most educational institutions have now incorporated information technology throughout their teaching and learning environments.

Streaming has now made video conferencing possible. Video conferencing is very convenient in that the members of an organization can attend the meeting regardless of their location. This saves costs of travelling and time. This also saves the organizational logistical and operational costs. As long as one has a computer, an internet connection and a web cam they can attend the meeting even in the comfort of their home. It is a popular way of collaborating these days.

Businesses have also used streaming to interact with consumers and deliver the right services and products. Social media sites such as Facebook, Twitter and YouTube have provided avenues for advertising and analysis of data generated by the users. This gives the business a competitive advantage over their rivals.

Information is made quickly available by live streaming, whereby events are webcasted to intended audiences as they happen. Social media sites such as YouTube and YouNow provide users with this capability for free.

Streaming has also created multibillion dollar companies that provide streaming services to millions of users across the world. Household names include the celebrated YouTube, YouNow the social media website, Facebook and Google (Google Hangouts). These companies contribute billions to the economy.

Other important areas where streaming has been implemented include; Satellite data real time processing, Scientific instruments, Patient monitoring, Stock exchange, the process industry and traffic control.

Challenges faced in streaming

Processing power- there is a need for scalable processing as distributed computing continues to grow in size. Work load could overwhelm servers.

Bandwidth- with increasing global access to streamed media, bandwidth could prove to be a problem to the content servers.

Device heterogeneity- there are literally thousands of devices from different manufacturers operating in the internet. All these devices need to be accommodated in the Internet of Things.

Advantages and disadvantages of streaming

Advantages of streaming

• It does not take up any hard disk space, since content is played as it arrives
• One can explore various videos/audio before accessing it
• Other electronic devices, such as the smart television can view the stream directly without the need of a computer.

Disadvantages of streaming

• Buffering can be a problem for links with low download rate.

References

[1] Kemp, S. (24 January 2017) Digital in 2017: Global Overview. Retrieved from https://wearesocial.com/special-reports/digital-in-2017-global-overview

[2] C. Hesselman, I. Widya, A.  Halteren , B. Nieuwenhuis,  Middleware support for media  streaming establishmentdriven by user-oriented QoS requirements. The Netherlands Telematica Instituut, Enschede, (2009)

[3] Rowe, Buevich, Maxim, et al. "Respawn: A distributed multi-resolution time-series datastore." Real-Time Systems Symposium (RTSS), 2013 IEEE 34th. IEEE, 2013.

[4] Nazim, Muhammad, Munam Ali Shah, and Muhammad Kamran Abbasi. "Analysis of Embedded Web Resources in Web of Things." Proceedings Appeared on IOARP Digital Library (2016).

[5] W. He, L. Da Xu, Integration of distributed enterprise applications: A survey. IEEE Transactions on Industrial Informatics, vol. 10 no.1, pp 35-42, (2014)

[6] R. Reed, “Streaming Technology Improves Student Achievement: Study Shows the Use of Standards-Based Video Content, Powered by a New Internet Technology Application, Increases Student Achievement. (Special Report)” in THE Journal (Technological Horizons In Education), vol.30 no.7 14, 2003

[7]Gray, G., Church, K., & Ayres, T. (2015). Virtual Credit Card Processing System. The ITB  Journal, 3(2), 2. 

[8] W. He,  S. Zha, L. Li, Social media competitive analysis and text mining: A case study in the pizza industry. International Journal of Information Management, 33(3), 464-472, 2013.

[9] R. Mehrotra, S. Abdelwahedy,  “A component-based framework for autonomic performance management in a distributed computing environment” in Computer Systems and Applications (AICCSA), 2014 IEEE/ACS 11th International Conference on ,pp. 493-500, IEEE, 2014

[10] M. Pathan, R. K. Sitaraman,D. Robinson, “Cloud-Based Content Delivery and Streaming, in Advanced Content Delivery,Streaming, and Cloud Services”, New Jersey: John Wiley & Sons, 2014