Prerecorded video

Updated: October 4, 2007

Applies To: Windows Server 2008, Windows Server 2008 R2

The bit rate of your digital media content is an even more important factor when trying to stream video content. To avoid long delays, gaps, and distortion during playback, the video streaming bit rate should accommodate the often limited bandwidth of your audience's equipment.

Video is simply a rapid display of a series of still pictures, called frames. Each frame must display a certain amount of detail, or resolution, to render the subject accurately. As the frame resolution is enhanced, more detail is shown. The number of frames displayed per second (fps) is known as the frame rate. As the frame rate increases, the motion in the video becomes smoother. The bit rate of the stream is determined by the combination of video frame rate and resolution. Both of these parameters can be modified during the encoding process to achieve the ideal bit rate for the user.

Over a high-speed Internet connection or a LAN, smooth, high-resolution video is easily transmitted. Extremely fast networks can render video and audio content that rivals the quality of a DVD; however, over a typical telephone connection, high-quality video becomes impossible without prohibitively long buffering times. There are techniques that you can use during the video production and encoding processes that will improve the audience experience regardless of the type of connection being used:

  • Keep movement to a minimum. Rather than send the entire picture of each frame in a video, a digital media stream only details the differences from one frame to the next. If the differences are kept to a minimum, the bit rate can be kept low. While creating video content, minimize movement of the subjects, the camera, and the backgrounds to reduce the amount of information that must be streamed later.

  • Keep the production design simple. You can often reduce the number of bits it takes to render a video frame by reducing the complexity of a scene being shot. Shooting a subject against a plain background requires less data transfer than shooting a subject in front of a multicolored or irregular background. You can also sacrifice some sound quality in exchange for improved video quality during the encoding process, if video quality is more important than audio quality.

  • Make use of the intelligent streaming capability of Windows Media Services. You can set the encoder to encode your digital media at several different bit rates. That way, no matter what type of connection the user has, the Windows Media server will be able to send a stream that is optimized for that bit rate.

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