Streaming servers (technology, tradeoffs, setup and management)
Planning and managing live broadcasts
Streaming non audio/Video content (text, images and animations)
SMIL (Synchronized Media Integration Language)
Management of media rights, authentication and conditional access
Create a live and on demand streaming media station with an accompanying website to house the links
Present the website
A Reminder…Standard Multimedia and The Web
Files must be downloaded first
Will not display until all downloaded
Usually launched in a separate application
Will not be linked to the information on the web page
May not be compatible
May need converting
May need plugins
Format specific to operating system
How does it work?
File encoded and compressed to a smaller file
Break it into small packets
Send them one after the other
When the packets reach their destination, they are decompressed and resembled into a form that can be played
Playing a music or video file as it is downloaded from the internet.
Copy is never stored on the user’s computer.
How does it work? (Cont)
To maintain the seamless play the packets are buffered
Process by which the media player downloads a few seconds of the media file prior to actual playback.
Allows for uninterrupted playback as when buffer plays more packets are downloaded and queued for playback
Streaming can be opened before a download is complete
Organised to be rendered ASAP
Play as data is received
Streaming media files maintain an open connection
Media server and media client negotiate connection
Sent over the connection until the entire file has been received
Media clients play data over the open connection
Is buffered to overcome congestion
How do you stream? Encoder Media Server Internet
How Does Streaming Work? 2 2 Web Server returns location of media file 1 User clicks on stream link 1 3 Media player is launched 3 5 5 Media server sends stream to media player 6 Media player decompresses and plays stream Web Server 4 Media player requests media file from media server 4 Media Server
Streams can be encoded and downloaded at different bit rates.
Measured in kbps (kilobits per second).
128 kbps is considered to be CD quality when using special codecs.
1-2Mbps is considered to be DVD / Broadcast quality.
User’s bandwidth determines that maximum bit rate that can be played.
Can select the usual connection speed or give various options
The process of digitizing and compressing a piece of traditional media into a format capable of being broadcast over the internet and played by a computer
Raw data is typically uncompressed
Big files - Contains all data essential to proper play
Raw data is then encoded (compressed) to stream
Encoders use audio and video codecs to compress data
Compression is different for audio and video
Stands for Compression and Decompression
Compresses multimedia content prior to transmission, and decompresses upon playback.
This uses less bandwidth and increases playback speed.
Users must have the proper media player to stream each format.
MPEG-1 layer 3 (MP3)
8 to 256kbs
Basic – 8 to 48kbs
Pro – 4 to 128kbs
2kbs to 2mbs
Real Video G2
Low motion, low bit rate
High quality images, low and high bit rates
Moving towards MPEG4 based standards
Low quality but fast
MPEG ( Moving Picture Experts Group ) , develops standards for digital video and digital audio compression.
MPEG-1 was designed for coding progressive video at a transmission rate of about 1.5 million bits per second. It was designed specifically for Video-CD and CD-i media.
MPEG-1 audio layer-3 (MP3) has also evolved from early MPEG work.
MPEG-2 was designed for coding interlaced images at transmission rates above 4 million bits per second.
MPEG-2 is used for digital TV broadcast and DVD. An MPEG-2 player can handle MPEG-1 data as well.
A proposed MPEG-3 standard, intended for High Definition TV (HDTV), was merged with the MPEG-2 standard
MPEG4 and beyond….
The standard for multimedia for the web and mobility.
MPEG-4 is able to throw away a lot more information and to save files 8 to 12 times smaller than those of MPEG-2.
Real power of MPEG-4 is the interactivity that can built into the video file or stream.
Multimedia producers and software and game developers can isolate parts of the video for particular special effects.
Pocket PC devices, and Windows CE already play back MPEG-4 and related codecs.
PacketVideo has a whole Web site full of short videos you can download wirelessly to your Pocket PC.
Encoding Streaming Video
Choice of formats
Real Video (Helix 10)
Windows Media (Version 10)
Flash Video Streaming (New up and coming)
Choice of delivery speeds
What connection are you streaming to?
Dial up modem (56Kbps)
ISDN/Dual ISDN (64/128Kbps)
Cable 128 up to 20 Mb per sec
ADSL (copper twisted pair up to 2Mbs at least)
T-1 (1.5Mb’s) T-3 45Mbps’s
E-1 (more commonly called 2Mbps pipe)
Considerations for streaming
Movie size – size affects bandwidth
Frame rates – broadcast TV is 25fps most webcasts are lower
Is it audio, video or both
Encoding the media – which format
Making a website which is suitable to play a streaming file.
Serving the media
What computer hardware do you need?
A standard web server with the correct software installed
A specialised media server
Both have streaming capabilities but why is one better than the other?
Live Streaming requires a dedicated media server
A web server is fine for low usage streaming files but if volume of people wishing to stream from your site is above 10 at a time you need a media server.
Media Servers give you much more control for your streams and offers many more services for your clients.
Media Servers enable 2 way communication the client can say rewind your media file (only for unicast).
Web Server V Media Server
Servers needed to serve streams.
In order to stream, a web site must install media servers into it’s network.
Capacity is typically measured by the maximum number of concurrent streams that the server can serve.
From a normal web server
Content has been encoded for one bit rate only
Not really streaming, just being downloaded
TCP will resend lost packets and could cause playback pauses
Dedicated media server
Content can be encoded at multiple bit rates and the server will choose the right one
Server uses proprietary protocol to control content – can choose best transport
Server is tuned to provide optimum performance under heavy use – big beefy machine, multiple CPU’s, high memory and disk drive space.
Microsoft Media Server
Quicktime Streaming Server / Darwin Streaming server
Hyperlinks use a linking file
Signals the browser to launch the streaming application
URL is passed indicating the server protocol, media server, and media file
RAM / RA – Realnetworks, ASX / WMX for Microsoft
Streaming between sender and a single recipient
Streaming between sender and multiple specific recipients
Streaming between a sender and any receiver
Live and prescheduled content
Some radio and television stations over WWW
Server Delivery Protocols
TCP/IP = Transmission control protocol/internet protocol.
Dedicated media servers use proprietary delivery protocols
Server attempts to provide content over UDP (User Datagram Protocol)
If unreliable or firewall then TCP is used
Allows server to control content
Content is streamed directly to the viewer and not saved or cached
Good Use Of Streaming
Short News Articles
Longer video broken up into chapters
Education and entertainment
Problems With Streaming
Screen size is small
Not ‘compelling content’
The internet may not be fast enough
Not TV Quality
Problems With Streaming (Cont)
Discard raw data until delivery requirements are met
Audio is poor quality
Video becomes jumpy and poor quality
Low speed series of still images
Display size for video is often reduced
User Datagram Protocol (UDP)
Bad packets are removed
Audio will drop and pop
Video will drop or loose frames
Blank frames may be displayed
Problems With Streaming (Cont)
Can loose its connection
If connection is lost playback will end and must be restarted
If network is congested network will pause or delay
Popular sites can become unavailable if the network and servers cannot cope the with demand
RA, RAM, RM
ASF, WMA, WMV
Real Audio / Real Video
The first and still most popular of the streaming solutions
Provides a complete creation, server and player solution
Helix announced in July 2002
Streams all formats
The Helix Platform
the first open, comprehensive platform of digital media products and applications for any format, operating system or device.
The Helix Community
enables companies, institutions and individual developers to access and license the Helix platform source code in order to build Helix-powered encoder, server and client products and other media applications for both commercial and non-commercial use.
Helix Universal Server
is a breakthrough product from RealNetworks that for the first time streams all major media types.
Real Networks Solutions
Assembles still photos and graphics with music and sounds
RealNetworks Streaming Media creation tool
Encodes existing and live content
Wizard plus point-and-click design tools
Next generation digital media production tool for broadcast streaming and download.
It provides robust, reliable, and fault-tolerant encoding to convert audio and video into RealMedia format.
Using RealMedia Events, Helix Producer can also be used to create synchronized multimedia presentations for playback within the RealOne Player.
Live and/or simulated live video and/or audio webcasts
On-demand audio and/or video
Synchronized multimedia using a combination of datatypes
Produces high quality broadband content
No longer it is necessary to maintain three different delivery infrastructures to reach the largest audience.
You can deliver all three major media formats over one delivery infrastructure. When you have a Helix Server, you have the capability to deliver media to any individual with a media player.
The RealNetworks system architecture based on the Helix platform has achieved unmatched performance.
Combine several different streams into a single file
The appropriate bit rate stream is automatically selected
Real Video 9
30% improvement over RealVideo 8
Same quality at half the bit rate of MPEG-4
Same quality at quarter the bit rate of MPEG-2
½ screen video at dial up rates
VHS quality at everyday broadband rates (starting at 160 Kbps)
Near DVD at 500 Kbps for download or streaming on high speed networks
Encorporates text, graphics, audio and video into a single format
Can be viewed with a time element
QT or MOV format available on Windows PC’s
Displays video, sound, animation, text and music.
Also 360 degree panaromas
Create, open, edit and save movies and audio
Resize movies and create streaming media
Quicktime Streaming Server
Serves Quicktime files stored on the server
Supports 2000 streams to Quicktime users
Requires Mac OS server
Quicktime Streaming Server
Instant-on provides enhanced overbuffering of data, dramatically reducing buffer time for broadband users.
Serves to any standard MP3 player such as iTunes, WinAmp, or QuickTime Player
Web-based interface for local and remote administration
Supports QuickTime (.mov), MP3 audio (.mp3), or MPEG-4 (.mp4) files
Allows you to create simulated live broadcasts with Playlist Broadcaster, perfect for creating your own Internet radio station
Supports up to 4,000 simultaneous streams
Supports both unicast or multicast streams
RealNetworks and Microsoft continue to battle for market leadership.
RealNetworks RealPlayer/Real One:
150 million registered downloads
85% market share
Microsoft Windows Media Player:
100 million registered users
Catalysts For Streaming Adoption
Availability of streaming content
The proliferation of streaming creation and playback tools lowers streaming costs.
Content providers are beginning view the Internet as a new distribution channel.
Formats are becoming transparent to the user.
New technologies that support payments.
Billing, payment and tracking systems.
Digital Rights Management.
Broadband Penetration The estimated 12 million users through college broadband networks are not included in these figures.
The technique is “similar to radio broadcasting except the Internet is used to send and receive audio instead of using the airwaves.” (Luini & Whitman. 2002)
Over 5000 (and counting) stations
1 MUSICMATCH Artist Match (non-commercial) www.musicmatch.com
2 K-LOVE (non-commercial) www.klove.com
3 AOL Top Country (commercial) http://music.netscape.com/radio/
4 AOL Top Pop (commercial) http://music.netscape.com/radio/
5 AOL Smooth Jazz (commercial) http://music.netscape.com/radio/
6 Virgin Radio/1215 AM & 105.8 FM (commercial) www.virginradio.co.uk
Facts - according to Arbitron Internet Broadcast Ratings
LAUNCH, the music destination on Yahoo!, approached 2.5 million listeners during the month of October 2003.
LAUNCH had 2,498,962 Cume Persons
(an estimate of the total number of unique users who listened for five minutes or longer during the reported time period).
Radio@AOL Network and LAUNCH were the top-ranked commercial with 27,379,327 and 18,311,876 hours of Total Time Spent Listening.
(the sum total of hours tuned by listeners to a given station or network.)
MUSICMATCH was the top-ranked non-commercial with 9,378,479 hours of TTSL.
Streaming radio is big: Over 22% of the US have listened to it.
Two categories of streaming radio stations
The Professional Station- Large amount of money, hardware and human resources, use professional encoders and servers
The Amateur Station - People broadcasting from home, shoutcast, winamp, s imple to set-up software requiring no money or large pieces of hardware, stream using a single machine, use free software as an encoder and server
If the user has a fast connection, streaming media is a practical way for broadcasting multimedia