What Is Streaming Video?
Definition:
Streaming video is a delivery method where a sequence of moving images with voice that are sent in compressed form over the network connection by a streaming provider and displayed by the viewer’s player as they arrive. With streaming video, a Web user does not have to wait to download a large file before seeing the video. Instead, the media is sent in a continuous stream and is played as it arrives. The player is a special program that uncompresses and sends video data to the display and audio data to speakers. Paramount to streaming video is a content management application that coordinates the components necessary to record, encode, stream, distribute and play a video over the network.
Streaming video can be sent from prerecorded video files (video on-demand), or can be distributed as part of a live broadcast. In a live broadcast, the video signal is converted into a compressed digital signal and transmitted from a special web server that is able to do multicast, sending the same file to multiple users at the same time.
Here’s a simple diagram of a streaming scenario of a live broadcast:
Some important considerations in the creation, management and delivery of streaming media include:
- Format – what method will be used to encode a video, enabling it for transport over the network efficiently, and played at the user’s desktop or mobile device? Adobe Flash and Microsoft Windows Media are two of the most commonly used formats.
- Network Transport – Efficiently using the network to send large video files (average can be 130 MB in size for a one hour video) to hundreds if not thousands of users is important to avoid ‘crushing’ the network and having impact on other applications. Unicast and Multicast networks are two common streaming protocols:
- Unicast protocols send a separate copy of the media stream from the streaming server to each recipient. Does not scale well when many users want to view the same program concurrently.
- Multicast protocols send a single stream from the streaming server to a group of recipients. Efficient use of the network but requires network configuration.
- Content Distribution Network – network appliance that resides in the network, usually close to user communities, where streaming video content is easily accessed and efficiently made available to user communities to help lessen the load on corporate networks, and ensure that both Live and video on demand assets are delivered successfully. Blue Coat, Cisco or Qumu MediaNet are examples.
- Player – Provide the type of experience expected at the user’s client – whether it’s compatible with their desktop system or browser and capable of delivering the experience expected. A wide variety of player choices is available, usually tied to one or more formats. Real, Windows Media Player, Silverlight or Adobe Media Player are examples.
- Streaming Server – Able to deal with various network transports and handle both Live and Video On-Demand capabilities in the format(s) of choice. Windows Media Server or Adobe Flash Media Server are examples.
- Content Manager – Handle the coordination of these devices to ensure that video assets are properly formatted and encoded based on users browser/player choice, efficiently managed, stored and made searchable on storage devices, and efficiently manage the preparation and delivery over the network to each respective user, in a controlled and secure fashion. No small task. Qumu Video Control Center is an example.
Additional learning sites include:
For a detailed explanation of streaming media, please see the “Streaming Media Explained” page on the StreamingMedia.com website:
http://www.streamingmedia.com/whatisstreaming.asp
For the Wikipedia discussion on Streaming multimedia:
http://en.wikipedia.org/wiki/Streaming_media
More information about Qumu:
