Basics of Streaming

Streaming is a technology in sending digital audio and video across the internet. The name is derived from how the digital images or sounds are “streamed” into the destination computer in many small pieces instead of delivering it in one big chunk as a whole.

Data streaming, commonly seen in the forms of audio and video streaming, is when a multimedia file can be played back without being completely downloaded on the computer. There are two ways to view media on the internet (such as video, audio, animations, etc) namely Downloading and streaming.

Streaming allows the end user to start viewing an audio or video file instantaneously once connection to a streaming source or relaying media server has been made. Streaming allows for the end user to listen and to view online media in real time.

A download, on the other hand, requires the end user to first receive the entire file before viewing actually begins. Downloads can potentially take up lots of time, while streaming allows for immediate access to the audio and video.

Streaming Media is the action of sending encoded (digitized) audio or video data out across the internet as a series of small data packets that may be viewed by the end user in a real time through the use of a Media Player.

The data stream is accessed via a Media Player (Windows Media, Win Amp, iTunes, Real, or QuickTime).Essentially the Media Player captures the data packets (stream of packets) and places them in their respective order for real time viewing.

When audio or video is streamed, a small buffer space is created on the user’s computer, and data starts downloading into it. As soon as the buffer is full (usually takes time in seconds), the file starts to play. As the file plays, it uses up information stored in the buffer, but while it is playing, more data is being downloaded.

As long as the data can be downloaded as fast as it is used up in playback, the file will play smoothly. Usually there is a delay of only 10-30 seconds before the audio or video starts to play. Streamed files also don’t require much bandwidth, so they can be played on computers that use modems to connect to the Internet.

Streaming architectures are made up of codecs. Codecs, short for compressor-decompressor, are basically mathematical formulas for handing video information. They mathematically compress video data into smaller file size. On the receiving end, they decompress that data into some form of displaying the video.

The key to streaming technology is file compression. Most music files are far too large to pass through the narrow bandwidth modems which are used to connect to the Internet. Compression removes some information from the original signal which are not perceived very easily by human ears as far as audio is considered, this process is called perceptual encoding which makes the file size lighter then the original ones. This creates a file that is small enough to download via a modem, but still sounds much like the original audio tracks.

Compression is only one part which makes streaming possible. There are also other special data-transfer schemes called as streaming protocols (such as Real Time Streaming Protocol),which makes streaming possible .Streaming protocols make sure you get the song in the right order and at exactly the right time so that while playing a particular song the listener does not feel any abruptness in the song.

Streaming of audio and video takes place with the help of various resources such as encoding station, video source etc.

The Encoding Station, has to be near the Video Source and it sends the compressed audio or video streams on to the Video Streaming Server (typically via a LAN using TCP [Transmission Control Protocol]).Individual compressed streams can vary from 20 Kbps (Kilobits/second) to 500 Kbps or more. The connection between the Encoding Station and the Video Streaming Server must be able to accommodate the total of the bandwidths of the individual streams and must be a clear and reliable connection.

The Video Streaming Server is responsible for delivering compressed video to each individual request for a particular video stream. The bandwidth connection to the Video Streaming Server must accommodate the total bandwidth of all the requests for a video stream so that quality of streaming is better on the destination computer.

A Video Player application is required to decode the specific video stream received by the system requesting the stream over the Internet. The most popular current video streaming applications are Real Networks and Windows Media player.