Streaming Media

What you need to know…

“streaming media”• Streaming is an emerging technology. You’ll find that there are many

diverse, and often quite confusing, definitions floating around.Streaming media is audio, full-motion video, and multimedia content—as opposed to other applications of streaming technology, such as the streaming of real-time stock quotes.

• Streaming media technology enables real-time or on-demand access to audio, video, and multimedia content via the Internet or an intranet.

• Streaming technology enables the near real-time transmission of events recorded in video and/or audio, as they happen—sometimes called “Live-Live,” and commonly known as Webcasting.

• Streaming technology also makes it possible to conveniently distribute pre-recorded/pre-edited media on-demand. In other words, media that is stored and published on the Web in streaming formats can be made available for access at any time.

Media Transmission

Streaming media is transmitted by a media server application, and is processed and played back by a client player application, as it is received.A client application, known as player, can start playing back streaming media as soon as enough data has been received—without having to wait for the entire file to have arrived. As data is transferred, it is temporarily stored in a buffer until enough data has accumulated to be properly assembled into the next sequence of the media stream. When streaming technology was first available, the ability to begin playback before the entire file had been transferred was a distinct advantage. Now, however, pseudo-streaming techniques, such as progressive download, allow some other formats to begin to play before file download is completed. So, while the ability to begin playback prior to completing file transfer is a characteristic of streaming, it is not, in and of itself, a differentiating factor.

Client – Server Connection

Automatic Protections• A streamed file is received, processed, and played

simultaneously and immediately, leaving behind no residual copy of the content on the receiving device.

• An important advantage of streaming media (unlike either traditional or progressive download) technology is the copyright protection it provides. No copy of the content is left on the receiving device*. Therefore, the recipient can neither alter nor redistribute the content in an unauthorized manner.

• GR note: there are now many “stream-capture utilities that allow exactly that, so the content-creator industry is moving to a system of digital “watermarking” and other encoding add-onswhich function to add “noise” to illegal captures.

Internet Radio

• Internet radio has been around since the late 1990s. Traditional radio broadcasters have used the Internet to simulcast their programming. But, Internet radio is undergoing a revolution that will expand its reach from your desktop computer to access broadcasts anywhere, anytime, and expand its programming from traditional broadcasters to individuals, organizations and government.

Why it’s Better than RadioTraditional radio station broadcasts are limited by

two factors: the power of the station’s transmitter (typically 100 miles) the available broadcast spectrum (you might get a couple of dozen radio stations locally)

Internet radio has no geographic limitations, so a broadcaster in Kuala Lumpur can be heard in Kansas on the Internet. The potential for Internet radio is as vast as cyberspace itself (for example, Live365 offers more than 30,000 Internet radio broadcasts).

No Limits• Internet radio is not limited to audio. An Internet radio

broadcast can be accompanied by photos or graphics, text and links, as well as interactivity, such as message boards and chat rooms. This advancement allows a listener to do more than listen. In the example at the beginning of this article, a listener who hears an ad for a computer printer ordered that printer through a link on the Internet radio broadcast Web site. The relationship between advertisers and consumers becomes more interactive and intimate on Internet radio broadcasts. This expanded media capability could also be used in other ways. For example, with Internet radio, you could conduct training or education and provide links to documents and payment options. You could also have interactivity with the trainer or educator and other information on the Internet radio broadcast site.

Something for Everyone

• Internet radio programming offers a wide spectrum of broadcast genres, particularly in music. Broadcast radio is increasingly controlled by smaller numbers of media conglomerates (such as Cox, Jefferson-Pilot, Bonneville and Clear Channel). In some ways, this has led to more mainstreaming of the programming on broadcast radio, as stations often try to reach the largest possible audience in order to charge the highest possible rates to advertisers. Internet radio, on the other hand, offers the opportunity to expand the types of available programming. The cost of getting “on the air” is less for an Internet broadcaster and Internet radio can appeal to “micro-communities” of listeners focused on special music or interests

Creating an Internet Radio Station

What do you need to set up an Internet radio station? CD player Ripper software (copies audio tracks from a CD onto a computer’s hard drive) Assorted recording and editing software Microphones Audio mixer Outboard audio gear (equalizer, compressor, etc.) Digital audio card Dedicated computer with encoder software Streaming media server

ExampleServer Main-board:Intel

SE7520JR2

No Guts, No Glory

• It’s all about the Horse-power: Dual Processors for Servers are the way to go—and at least 1GB of RAM

Getting Audio over the Internet1.1. The audio enters the Internet broadcaster’s encoding The audio enters the Internet broadcaster’s encoding

computer through a sound card. computer through a sound card. 2.2. The encoder system translates the audio from the The encoder system translates the audio from the

sound card into streaming format. The encoder sound card into streaming format. The encoder samples the incoming audio and compresses the samples the incoming audio and compresses the information so it can be sent over the Internet. information so it can be sent over the Internet.

3.3. The compressed audio is sent to the server, which has a The compressed audio is sent to the server, which has a high bandwidth connection to the Internet. high bandwidth connection to the Internet.

4.4. The server sends the audio data stream over the The server sends the audio data stream over the Internet to the player software or plugInternet to the player software or plug--in on the in on the listener’s computer. The pluglistener’s computer. The plug--in translates the audio in translates the audio data stream from the server and translates it into the data stream from the server and translates it into the sound heard by the listener.sound heard by the listener.

2 Ways to Deliver Internet Audio• In downloads, an audio file is stored on the user’s

computer. Compressed formats like MP3 are the most popular form of audio downloads, but any type of audio file can be delivered through a Web or FTP site. Streaming audio is not stored, but only played. It is a continuous broadcast that works through three software packages: the encoder, the server and the player. The encoder converts audio content into a streaming format, the server makes it available over the Internet and the player retrieves the content. For a live broadcast, the encoder and streamer work together in real-time. An audio feed runs to the sound card of a computer running the encoder software at the broadcast location and the stream is uploaded to the streaming server. Since that requires a large amount of computing resources, the streaming server must be a dedicated server.

Home Sweet Home Servers

• A “home server” is not a streaming server, instead it is simply a machine dedicated to acting like a giant filing cabinet for an entire home network.

• a popular way to re-purpose an older computer: since you don’t actually do work on that system (you’ll use it only for file storage) it doesn’t need to be very powerful at all. Sinceit’s in the home, security isn’t much of an issue.

• Put all your old drives to work again in this machine, and stick all your seldom accessed files on this machine, and just make it the hub of your home network

LINUX

• Linux (often pronounced LIH-nuhks with a short "i") is a Unix-like operating system that was designed to provide personal computer users a free or very low-cost operating system comparable to traditional and usually more expensive Unix systems. Linux has a reputation as a very efficient and fast-performing system. Linux's kernel (the central part of the operating system) was developed by Linus Torvalds at the University of Helsinki in Finland. To complete the operating system,Torvalds and other team members made use of system components developed by members of the Free Software Foundation for the GNUProject. Linux is a remarkably complete operating system, including a graphical user interface, an X Window System, TCP/IP, the Emacseditor, and other components usually found in a comprehensive Unix system.

• LINUX is an increasingly popular FREE OS well-liked as a server!

Web Servers& Clients

here are the basic steps that occur behind the scenes: The browser broke the URL into three parts: 1. The protocol ("http") 2. The server name ("www.thenamedsite.com") 3. The file name ("web-server.htm")

The browser communicates with a name server to translate the server name "www.thenamedsite.com" into an IP Address, which it uses to connect to the server machine. The browser then forms a connection to the server at that IP address on port 80. Following the HTTP protocol, the browser sent a GET request to the server, asking for the file "http://computer.thenamedsite.com/web-server.htm." (Note that cookies may be sent from browser to server with the GET request)The server then sent the HTML text for the Web page to the browser. (Cookiesmay also be sent from server to browser in the header for the page.) The browser read the HTML tags and formatted the page onto your screen.

World’s Tiniest Web

Server• The single chip computer in the above picture runs the iPic web-server, the

world's tiniest implementation of a TCP/IP stack and a HTTP web-server. The chip above is a complete micro-computer, and it includes all components of a complete computer on a single tiny micro-chip (this includes the CPU (central processing unit), memory, serial port interface circuitry, and clock oscillator).

• The chip is connected directly to an Internet router, which is essentially the same as an Internet connection from an ISP. When you visit the iPic Web-server, your web-browser connects to the chip shown in these photographs and the web-pages you see are sent to your web-browser directly from the tiny chip.

• BROWSE THE CHIP HERE: http://www-ccs.cs.umass.edu/~shri/iPic.html

Benefits of Specialized Servers

•• The benefits of using a specialized The benefits of using a specialized streaming media server include:streaming media server include:

• • More efficient use of the network More efficient use of the network bandwidthbandwidth

• • Better audio and video quality to Better audio and video quality to the userthe user

• • Advanced features like detailed Advanced features like detailed reporting and multireporting and multi--stream multistream multi--media contentmedia content

• • Support for large numbers of usersSupport for large numbers of users• • Multiple delivery optionsMultiple delivery options• • Content copyright protectionContent copyright protection

Streaming Media Software

•• Some of the more popular streaming media Some of the more popular streaming media software aresoftware are RealSystemRealSystem Server, Server, QuicktimeQuicktime(Darwin Streaming Server), and Microsoft Media (Darwin Streaming Server), and Microsoft Media Services, as well as audio streaming servers likeServices, as well as audio streaming servers likeIcecastIcecast. Servers configured with streaming server . Servers configured with streaming server software are built for streaming. They have the software are built for streaming. They have the added benefit of streaming protocols that you added benefit of streaming protocols that you can’t get with a Web server configuration.can’t get with a Web server configuration.

•• tip: the Darwin server is completely FREE, unlike tip: the Darwin server is completely FREE, unlike most others, and yes, it works on a PC! most others, and yes, it works on a PC!

Content Creation for Streaming

Video Streaming• In order to deliver your video using “true streaming” you

must place your video file on a specialized streaming server. RealNetworks provides RealServer, which runs on a variety of operating systems, including Windows NT/2000, Linux 2.2, Solaris 2.6/2.7/2.8 and IRIX 6.2/6.5. Microsoft provides Windows Media Services (for low to mid-bandwidth networks) or Microsoft NetShow Theater Server (for high band networks), which runs on a Windows NT/2000/XP Server. Apple provides QuickTime Streaming Server which runs on a Mac OS X Server. When you stream RealMedia or QuickTime files you may use the RTSP protocol (instead of HTML). When you stream Windows Media files with a NetShow Sever you may use the MMN protocol. When you stream Windows Media files with Windows Media Server you may use the MMS or MSBD protocol.

Video is Served

Down on the Farm• A server farm is a group of computers acting as servers and housed

together in a single location. A server farm is sometimes called a server cluster. A Web server farm can be either (1) a Web site that has more than one server, or (2) an Internet service provider (ISP) that provides Web hosting services using multiple servers. In a business network, a server farm or cluster might perform such services asproviding centralized access control, file access, printer sharing, and backup for workstation users. The servers may have individual operating systems or a shared operating system and may also be set up to provide load balancing when there are many server requests. In a server farm, if one server fails, another can act as backup.

• On the Internet, a Web server farm, or simply Web farm, may refer to a Web site that uses two or more servers to handle user requests. Typically, serving user requests for the files (pages) of a Web site can be handled by a single server. However, larger Web sites may require multiple servers.

• Web farm is a term that is also simply used to mean a business that performs Web site hosting on multiple servers. Some Web farms allow you to put your own server on their site, a service known as colocation.

Server Farms

The STONE “SouperComputer”

Currently 155 nodes large! 1000 node Farm

GOOGLE has one of the largest server farms in the world—well over 10,000 nodes!!!

UDP (User Datagram Protocol)

• Like TCP, UDP runs on top of IP networks. But unlike TCP, UDP doesn’t have re-transmission and data-rate management services, meaning it’s fast enough for real-time audio and video delivery. UDP traffic also enjoys a high-priority status on the Internet, making it a fairly smooth, uninterrupted ride for media running over the public network. Overall, it’s suited to media, which is more sensitive to variances in bandwidth availability than short-session TCP traffic like e-mail. There has been a fair amount of discussion regarding whether or not trafficking data over UDP is as secure as on TCP, but from a pure streaming standpoint, UDP is the preferred option.

MMS (Microsoft Media Services)

• Microsoft’s streaming server uses the MMS protocol to transfer unicast data. MMS can be transported via UDP or TCP. If the client Windows Media Player cannot negotiate a good connection using MMS over UDP, it will resort to MMS over TCP. If that fails, the connection can be made using HTTP over TCP, which is not as ideal for streaming as MMS over UDP, but ensures connectivity nonetheless.

RTSP/RTP (Real Time Streaming Protocol/Real Time Transport Protocol)•• RTSP is a control or communication protocol used RTSP is a control or communication protocol used

between client and server, and RTP is the data between client and server, and RTP is the data protocol used by the server to send data to the protocol used by the server to send data to the client. Unlike HTTP and FTP, RTP doesn’t client. Unlike HTTP and FTP, RTP doesn’t download the file to the client but instead plays it download the file to the client but instead plays it in realin real--time. The Darwin Streaming Server andtime. The Darwin Streaming Server andRealSystemRealSystem Server use RTSP/RTP to Server use RTSP/RTP to communicate with one another.communicate with one another. RealSystemRealSystemServer also uses RDT, its proprietary data channel, Server also uses RDT, its proprietary data channel, for delivery tofor delivery to RealONERealONE players. players.

Unicast & MulticastUnicast -The server serves streams to each and every unique client requesting access. Multicast - Instead of serving streams to each and every user requesting access, only one served stream is sent to all clients. Multicast is the most efficient use of bandwidth for large numbers of clients. It uses the same bandwidth for 100 clients as it does for one. To do multicasting, however, all routers in the path may require a software, firmware, and in some cases, a hardware upgrade. The entire delivery path must be multicast-enabled, and so far, Internet Service Providers have shown little interest in updating their systems for multicasting. For this reason, multicasting is used on private networks or Intranets and is not yet available on the public Internet, although there’s experimentation being done with the Mbone project (Multicast backbone).

Unicasting Pros & Cons

Multicasting Pros & Cons

Keep in MindKeep in Mind• While streaming media servers use these specialized

protocols to stream content over the public Internet, they also use the HTTP/TCP protocols used by Web servers in order to get streams through corporate firewalls, which are often set up to block UDP traffic. Check to make sure the server software you’re considering has a rollover scheme to transport your media through various firewalls if need be. Another thing to check when shopping for streaming server software is the number of simultaneous streams it can put out at one time. That number ranges from 25 to 10,000. Microsoft and Darwin streaming server software are open-source, so these are available at no charge. Microsoft Media Services comes standard with Windows 2000 server at no additional cost. RealSystem Server is free up to 25 clients, but Real charges per concurrent user after that.

Streaming media systems• Andromeda (http://www.turnstyle.com/andromeda) (for PHP or ASP)• Apple's QuickTime• DarkIce [1] (http://darkice.sourceforge.net/)• Forbidden (http://www.forbidden.co.uk/)• Flumotion [2] (http://www.flumotion.net) (Distributed streaming media server)• FFmpeg• Helix Community• Icecast• Microsoft's Windows Media• MuSE [3] (http://muse.dyne.org/)• MPEG-4• PeerCast [4] (http://www.peercast.org/)• RealNetworks' RealSystem• SHOUTcast from Nullsoft• Streamripper [5] (http://streamripper.sourceforge.net/)• VideoLAN• Clipstream (http://www.clipstream.com/) (playerless audio and video streaming

technology)• Web Video 4 U

HAPPY STREAMING!HAPPY STREAMING!

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