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| Video Caster: Streaming Media Formats |
Streaming Media Formats
Streaming Media is a technology that enables online users to click on a link and view video and audio (collectively referred to as Media Files). The media file that the user views is present on a streaming server that is responsible to send video/audio data over the Internet. The viewing application (generally a media player) knows how to read this data and displays it to the viewer. This is the process of streaming. A streaming server can stream data from media files physically present on the hard drive or stream data from a live source like a web camera or microphone.
Most online users have a 56Kbps dial-up connection or a 128Kbps broadband connection. “Bandwidth” is the term used for referring to the connection speeds available to a user. Normally, bandwidth required to view a - quality video is 1500Kbps-2Mbps. This is very high when compared to the available internet bandwidth. Moreover, the actual bandwidth that is available to a user fluctuates depending on the internet traffic. The streaming media file creation tool therefore has to compress, encode and apply a variety of other schemes to fit the data into the available bandwidth. After creating such a file, the streaming server and the media player combined provide the ultimate viewing experience. This is what characterizes a streaming media format (like WMV, WMA or ASF) to a file meant for playing locally on your computer (like MPEG, AVI etc.)
Streaming media technology makes videos play seamlessly over the network. However to achieve this goal, the media content author (one who creates streaming media files) must create files with the right bit-rate (rate at which a file must be streamed so that users can view them). For example, a video created at bit-rate 128Kbps will not be visible to users with a 56Kbps internet connection. You can off-course encode the video at 56Kbps but then you risk losing video quality and maybe you may have to create a video with lower width and height (dimension). A better solution is to create two videos – a low quality/less dimension video for 56Kbps and a relatively high quality/high dimension video for 128Kbps users. This solution is however not suitable when the number of network connections you need to support is more. Moreover, if a 128Kbps connection suddenly drops to 56Kbps due to network traffic, the video runs the risk of stopping.
A more advanced technology in the field of Streaming Media is the ability to encode multiple streams at different bit-rates within the same file. Such Mutual Exclusion by Bit Rate (MBR) files, for example, can contain streams encoded at say 24Kbps, 56Kbps, 128Kbps and 256Kbps. This implies that users can view such a video over bandwidths ranging from 24Kbps to 256Kbps. The streaming server and the media player together also make sure that the video adapts to a fluctuating internet connection. For example, if a 128Kbps connection drops down to 56Kbps then the streaming server automatically starts streaming the 56Kbps stream instead, providing uninterrupted video playback. The only difference a viewer might notice is a change in video quality.
Windows Media 9 is a streaming media format available for the Windows platform and is increasingly becoming the most popular format. Along with streaming capabilities, Windows Media 9 also supports High Definition videos that are comparable to traditional formats like MPEG (VCD/DVD) and take up less disk space.
Why use Streaming Media Format?
- Video Files are Very Large: Video files meant to be played on your computer like MPEG, AVI etc. take up a lot of disk space. The bandwidth required to play them is in the range of 1500Kbps to 2Mbps or even higher. To play them across the internet they must take up less space so that the bandwidth requirement is significantly less depending on the internet connection speed. Streaming Media Format uses various compression techniques to make video files very small in size.
- Not Downloaded to Viewer's Computer: Streaming media files are streamed. Unlike other video clips, these files are never downloaded to the viewer's computer. They are therefore protected. Viewers cannot manipulate streaming media files in any way nor can they distribute copies of the media file.
- Monitoring Capability: The streaming media server has reporting capability that enables you to monitor any media file for the number of times they are streamed, the amount of bandwidth they consume, the peak hours when they are most frequently streamed etc. These reports help you analyze and further enhance the online viewing experience of your website.
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