Unit 5 Using Media and Streaming

Understanding the Streaming Process Streaming Media Means?

Streaming media is video or audio content sent in compressed form over the Internet and played immediately, rather than being saved to the hard drive. With streaming media, a user does not have to wait to download a file to play it. Because the media is sent in a continuous stream of data it can play as it arrives.

Advantages of streaming media Makes it possible for users to take advantage of interactive applications like video search and personalized playlists. Allows content deliverers to monitor what visitors are watching and how long they are watching it. Provides the content creator with more control over his intellectual property because the video file is not stored on the viewer's computer. Once the video data is played, it is discarded by the media player.

live or on-demand ? Streamed material can be live or on-demand.

live or on-demand Live streaming is called progressive streaming or progressive download, while on-demand streaming is from material that is already stored to disk. In a live broadcast, the video signal is converted into a compressed digital signal and transmitted from a Web server as multicast, sending a single file to multiple users at the same time.

Streaming media is transmitted by a server application and received and displayed in real-time by a client application called a media player. A media player can be either an integral part of a browser, a plug-in, a separate program, or a dedicated device, such as an iPod. Frequently, video files come with embedded players. YouTube videos, for example, run in embedded Flash players.

Live streaming

On-demand streaming

How to Decide Which Protocol ? Protocol in use How to Decide Which Protocol ?

Protocol Deciding A digital audio or video file is partitioned into many small pieces and played back at high speed. Depending upon the nature of the material, playing streamed material can suffer a certain amount of loss of transmitted packets, which is displayed as dropped frames or missing notes without the viewer noticing. This difference between streamed media and transferred media is fundamental in deciding which transfer protocol to use.

TCP or UDP ? For transferred media, the entire file must be transmitted with fidelity, thus TCP (Transmission Control Protocol) is the transmission protocol. In a streamed media scenario, fidelity isn't a prerequisite, thus UDP (User Datagram Protocol) is the transmission protocol.

Cloud computing in media Streaming

Cloud computing advantages(1) Access to large scale storage, which enable the storage of large media files and on-demand media libraries. Example:- Amazon S3, Microsoft Windows Azure Blob Storage, Nirvanix, EMC Atmos Online, Mezo, Google Storage for Developers. Rackspace CloudFiles, and Eucalyptus are examples of some of the large cloud storage systems available to content providers. Some of these systems, such as Microsoft Azure and Google Storage, support the applications developers' position on those SaaS services.

Cloud computing advantages(2) Access to scalable compute engines and network storage that can serve as the streaming server to large audiences. .

Cloud computing advantages(3) • Access to a scalable compute engines that can be useful when you want to perform encoding/decoding or transcoding on media files. Example:- The company Encoding.com is an example of a transcoding service where you can use an Adobe AIR application to drag and drop files that are encoded right to your desktop. Ex. AVI to WMV encoding ,

Cloud computing advantages(4) • Access to content delivery networks or edge systems that can push content out to users based on geographical location.

Audio streaming Audio streaming is the practice of delivering real-time audio through a network connection. In general, audio streaming utilizes a buffering system and a secure data stream platform to allow end users to listen to full audio files without interruption. This type of data streaming also requires significant bandwidth. Experts point out that high-quality audio streaming is a somewhat recent phenomenon, and that in previous decades, a lot of major types of connections such as dial-up Internet or slower bandwidth offers would not accommodate uninterrupted audio streaming.

Audio streaming Audio streaming makes much lower demands on network bandwidth than video streaming does. An audio file is roughly 500 times smaller than a correspondingly long video file. Therefore, the first streaming services that appeared even before broadband became widely available were audio streaming services. An early entrant into this area was Real Networks' Real Player technology and its associated protocol suite. There was a time when many content providers required you to use RealAudio technology and the RealPlayer media player. Two other competing formats appeared that have gotten general acceptance: Windows Media Player and Apple QuickTime. These players play video formats as well as audio formats, and all are available as stand-alone players or as browser plug-ins. But trend has been shifted from proprietary formats to standard formats. Today MP3 is King.

Audio streaming

RTP RTP (Real-time Transport Protocol) The aim of RTP is to provide a uniform means of transmitting data subject to real time constraints over IP (audio, video, etc.). More generally, RTP makes it possible to: identify the type of information carried, add temporary markers and sequence numbers to the information carried, monitor the packets' arrival at the destination. In addition, RTP may be conveyed by multicast packets in order to route conversations to multiple recipients.

RTP typically runs over User Datagram Protocol (UDP). RTP is used in conjunction with the RTP Control Protocol (RTCP). While RTP carries the media streams (e.g., audio and video), RTCP is used to monitor transmission statistics and quality of service (QoS) and aids synchronization of multiple streams. RTP is one of the technical foundations of Voice over IP and in this context is often used in conjunction with a signaling protocol such as the Session Initiation Protocol (SIP) which establishes connections across the network

RTCP & RTSP RTCP (Real-time Transport Control Protocol) RTCP protocol is based on periodic transmissions of control packets by all participants in the session. It is a control protocol for RTP flow, making it possible to convey basic information on the participants of a session and the quality of service. The Real Time Streaming Protocol (RTSP) is a network control protocol designed for use in entertainment and communications systems to control streaming media servers. The protocol is used for establishing and controlling media sessions between end points.

VOIP VOIP is an acronym for Voice Over Internet Protocol, or in more common terms phone service over the Internet. If you have a reasonable quality Internet connection you can get phone service delivered through your Internet connection instead of from your local phone company.

Working with VOIP applications Voice over IP or VoIP is a set of communication protocols for delivering voice over the Internet. Some of these services have been migrated to the cloud, particularly those services that require the involvement of large number of servers. VoIP uses additional protocols and standards other than audio streaming; these are the most commonly used VoIP standards: • H.323 • IP Multimedia Subsystem (IMS) • Media Gateway Control Protocol (MGCP) • Session Initiation Protocol (SIP) • Real-time Transport Protocol (RTP) • Session Description Protocol (SDP) Examples:- Skype Google voice and Google talk

Why use VOIP? Lower Cost- In general phone service via VOIP costs less than equivalent service from traditional sources. This is largely a function of traditional phone services either being monopolies or government entities. There are also some cost savings due to using a single network to carry voice and data. This is especially true when users have existing under-utilized network capacity that they can use for VOIP without any additional costs. Increased Functionality- It is portable than traditional landlines generating huge bills.

Video Streaming Video streaming over the Internet has become one of the major broadcast transmission media in a rather short time. Many trends have come together to help make this transition a reality, including broadband networks, high-capacity commodity disk drives, low-cost computing power, and now cloud computing. Video streaming is one of these technologies that benefits greatly from deployment in the cloud. Example:- YouTube

Television in cloud Television is a very important industry. The average American watches five hours of TV a day, and $70 billion a year is spent on advertising. The number of TV watchers dwarfs the 1 billion PC users, and even the 2 billion cell phone users. Worldwide, there are 4 billion TV watchers. Many TV stations have begin to put their series episodes and movies on internet sites such as ABC.com, StarhotSpot, AppleTV, GoogleTV etc.

Streaming video formats • Firefox 4 (WebM) • Chrome (h.264 supported now, WebM enabled version available via Early Release Channel) • Opera 10.6+ (WebM) • Apple Safari (h.264, version 4+) • Microsoft Internet Explorer 9 (h.264, Platform Preview 3) • Microsoft Internet Explorer 6, 7, or 8 with Google Chrome Frame installed You should expect HTML5 to be standard in the official release versions of these browsers before 2010 ends.

You also can view HTML 5 content in the following media players: • Media Player Classic (http://mpc-hc.sourceforge net/) • Moovida Core (http://www moovida.com/) • VLC (http://www.videolan.org/) • Winamp (http://www.winamp.com/media-player/) • XBMC (http://xbmc.org/) Video formats are only half of the story when it comes to video file formats. The second half of the story is the format for the streaming protocol that encodes the video file. Several of these container formats are in use. The most widely used streaming video file container format is H.264/MPEG-4 Part 10. MPEG-4 Part 10 is also known as MPEG-4 AVC, which stands for Advanced Video Coding.