RealVideo relies upon a video server to send data, which makes better use of the
bandwidth and improves the overall performance of the streaming video. RealVideo
supports both live interactive and on-demand video and includes a number of tools to
helptheproducerandtheserverandimprovethevideofile’sreproduction.Themoreim-
portant tools in RealVideo are: Stream thinning Dynamically adjusts the video frame rate in real-time to the
lowest rate that will accommodate the type of content, which reduces the need
to pause the transmission and buffer data. This is particularly effective for activity
during peak load periods.
Smart networking Allows RealVideo to deliver a streaming signal across
any network. It is compliant with firewall standards and will communicate on
internal networks and intranets using a variety of protocols including HTTP.
TV mode Plays a video stream in a television-like window on the viewers
desktop while they work with other applications, including a browser. This is a
feature Yahoo’s Broadcast.com uses in their live television feed over the Internet.File Sizes
Video files store a lot of data and can become very large. As an illustration of how large
they can get, consider that a 24-bit, full screen, 30 frames per second video file would con-
sume around 1.6GB of file space. How so?
Its file size is calculated as follows:- Three bytes (representing the 24 bits used for video encoding) times 640 (width
of the frame) times 480 (the height of the display frame), which equals the number
of pixels in a full frame display. - The number of pixels in the full frame display times 30 (the frame rate) times
60 (the number of seconds the video file will run) equals 1,658,880,000 bytes or
1.6GB of storage space for each minute of video.
This doesn’t include the audio track which would add another 5 to 10MB. This is why the
AVI files distributed on the Windows 98 CD range from 25 to 50MB for 16-bit video files
that run an average of two minutes. A video file contains the equivalent of 15 to 30 JPEG
files for each second of video.
There are several ways in which the size of a video file can be reduced: Decrease the size of the playback window. For example, video files played over
the Internet use a standard 160 ×120 pixels. But remember that the smaller the
window, the harder it will be to see any text or detailed movements in the video,
especially on a 14-inch monitor.
Reduce the color count from 16 million to 256, or perhaps even 16 colors. Better
yet, if possible, convert the video to black and white. Of course, the visual quality
of the file will also be reduced right along with the color count.(^560) PC Hardware: A Beginner’s Guide