The first step that you need to take to stream live or on-demand content is to encode your audio and/or video. Before you can encode your audio/video, you will need to choose the quality of each bit rate stream that will be made available to your clients. Some general guidelines on how to choose bit rate quality are provided below.
Tip: Smooth Streaming excels when it can choose between various bit rate streams. This allows it to match video quality more closely to a user’s environment. However, keep in mind that increasing the number of bit rate streams also increases CPU usage and the minimum amount of Internet bandwidth capacity for the computer hosting the encoder.
Note: Microsoft Expression Encoder automatically chooses default bit rates according to the selected output format. However, you may always add, modify, or delete the existing default bit rates.
Once you have chosen which bit rate streams will be created, the encoder will convert your audio/video into a MP4 file for each one of them. The type of MP4 file that will be created depends on whether the target media is audio & video or audio only. If you have an audio/video stream, then an ISMV file will be generated. If your stream is audio only, then an ISMA file will be generated. In addition to the MP4 file, the encoder will also generate a server manifest file (ISM) and a client manifest file (ISMC). The server manifest file provides information about the stream, such as the available bit rate streams and the files to which they are mapped, to IIS. The client manifest file provides the Silverlight player with the information it needs to dynamically switch between different bit rate streams.
Reminder: In order to stream a live event to iOS devices, it must be encoded as H.264 video and AAC audio codecs.