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Planning prerecorded content

You can use your knowledge of your system capabilities and the capabilities of your audience to plan and develop content that will preserve as much of the quality of the original as possible throughout the encoding and streaming process. The planning process for prerecorded content differs significantly from the planning that must take place for live content.

For example, if the bit rate of your streaming audio files is too high for your audience's bandwidth capability, the stream will be forced to pause during playback so the player can buffer the content. If your bit rate is too low, the sound quality will suffer. Small adjustments to the encoding process, such as switching from stereo sound to mono sound, can reduce the required streaming bit rate by as much as half without impacting the quality of the sound.

You are also likely to encounter situations in which you will be streaming content to a wide range of audience bandwidth profiles: some on a local area network (LAN), others using a digital subscriber line (DSL), and still others connected through dial-up modems. Careful preparation of your content will allow you to stream content to all of these audiences simultaneously while providing each with the best possible quality.


You can stream audio content in either Windows Media Audio (WMA), ASF, or MP3 formats by using Windows Media Services. Prepare your audio content by converting or encoding it into one of these file formats.

Bandwidth is a concern when attempting to stream audio content. A high-quality stereo broadcast can easily overwhelm the abilities of a standard dial-up modem. There are several configurable components of an audio recording that can be adjusted during the encoding process to help you achieve the right balance of data transfer rate and audio quality. It is a good idea to experiment with your encoding process to find out what combination of settings works best for you. For more information about how audio content is prepared for streaming, see Windows Media Encoder Help.

If your audio content comes from several different sources, you may find that the quality of your content is inconsistent. Try to maintain a smooth, unbroken quality flow from one content file to the next.


The bit rate of your digital media content is an even more important factor when attempting 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 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:

For more information about encoding, see Windows Media Encoder Help.

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