Streaming Media : From Neeta Verma, Anil Rathore - NIC HQ Streaming media technology enables the live or on demand distribution of audio, video and multimedia on the internet. Streaming media is distributed as a continuous real-time stream and starts displaying video or playing back audio as soon as enough data has been received and stored in the receiving station’s buffer. The viewer no longer has to wait for long to hear or see a few minutes of downloaded audio and video, as in the past Streamed media can be accessed or viewed on anything from an ordinary telephone line to a broadband connection. How Streaming works ? To stream media via the Internet one needs to convert it to digital format using a capture card. Next compress that media with an encoder so that it can travel efficiently over the Internet. And lastly media files are streamed from a server for clients to access/ view. Major components of this technology are :

  1. Capture Card : This is a special piece of hardware installed on a computer that can translate video and audio input from a video source, such as a camcorder, into digital format and write it to the hard disk in a number of formats, some of which can be compressed and streamed. A sound card available on your computer is usually sufficient for audio digitization for streaming.
  2. Encoder : In order for the data to stream efficiently over the Internet to a range of targeted bandwidths, it must be compressed into small information packets. This compression is done with the software, often called an “encoder”.
  3. Media Server : Media Server is an Internet server equipped with a special piece of software known as streaming server . Media is finally streamed using this server. The streaming server software determines the types of streamed media-such as RM or ASF-it can stream. Generally they are capable of streaming in multiple formats.
  4. Player : A player is a software application that receives streaming (digital) media from a Media server, decodes it and plays it back on the computer.
  5. Protocols : Streaming media products use proprietary protocols to communicate between a client & server. However of late, most of them are also supporting HTTP in addition to their proprietary protocols.

On-Demand vs Live Web Cast On Demand Audio/Video : Pre-recorded clips are delivered, or streamed, to users upon request. A user who clicks a link to an on-demand clip watches the clip from the beginning. The user can fast-forward, rewind, or pause the clip. Therefore on demand streams can be created from archived live events or recorded clips. Live Web Cast of Audio/Video : Web casting, which is also known as Internet broadcasting, is the transmission of live or pre-recorded audio or video to personal computers that are connected to the Internet. A user who clicks a link to a live clip joins the live event in progress. Because the event is happening in real time, fast-forward, rewind, and pause capabilities are not available. Web casts are most suitable for high demand live presentations to large geographically dispersed audiences. Participants can attend these virtual presentations from their desktop by visiting a web site. Interaction between instructor and learners occurs in real-time. Participants can use a chat window to type in questions to the presenter during the session. Web casts simulate the look and feel of a live event and can even be recorded for later viewing for those who missed the original web cast. This method is also less expensive than satellite broadcasting. Popular Streaming Technology Products Real Networks Technology (http://www.realnetworks.com)

  1. Encoder : Real / Helix Producer
  2. Server : Real /Helix server.
  3. Player : Real Player.
  4. Protocols : RTSP, PNM, HTTP

Microsoft Media Technology (http://microsoft.com/windowsmedia)

  1. Encoder : Windows Media Encoder
  2. Server : Windows Media server.
  3. Player : Windows Media Player
  4. Protocols : MMS, HTTP

Multimedia Presentations on the Web The Synchronized Multimedia Integration Language (SMIL, pronounced “smile”) enables simple authoring of interactive audiovisual presentations. SMIL is typically used for multimedia presentations which integrate streaming audio and video with images, text or any other media type. SMIL is an easy-to-learn HTML-like language, and we can write SMIL presentations using a simple text-editor. Streaming Media Facilities at NIC NIC has set up state of art infrastructure to provide streaming media services. Facilities for on-demand as well as live web cast are available. Web Services and Multimedia Application Division at NIC hq is maintaining Media Servers to support both the popular technologies i.e. Real Network and Microsoft Media are supported. For further information or to avail these services please log on to http://webservices.nic.in or contact at wsmad@hub.nic.in