Experiencing Internet media via the download-and-play method means exactly that-your computer downloads a compressed media file, such as MP3, from the Internet to your hard drive. Once that file has downloaded completely, the media starts to play. With real-time streaming, on the other hand, the media is broadcast directly to your computer from a server and played back as the information is received from the server. HTTP Streaming (download-and-play) Also known as progressive streaming, this method takes a compressed media file and downloads it to your computer's hard drive before playback using any Web server such as Apache, Roxen, Microsoft Internet Information Server or Netscape. Real Time Streaming Real-time streaming is broadcast to your computer directly from a server and played back as the information is received from the server, without waiting for the file to download. Real-time servers include the RealSystem Server and QuickTime's Darwin streaming server. Q. What do I need to begin streaming? A. To stream media via the Internet you first need some "content," such as audio or video, images, text or animation. You'll need to convert it to digital format (e.g., .avi for video or .wav for audio) using a capture card. Next you must compress that media with an encoder so it can travel efficiently over the Internet. And lastly you need a server to send the media to a player upon request. These definitions will be helpful as you learn more about streaming media: Capture Card This is a special piece of hardware, such as the Osprey 100, installed on a computer that can translate video and audio input from a video source, such as a camcorder, into digital format and write it to the hard disk in a number of formats, some of which can be compressed and streamed. A sound card-you probably already have one on your computer-is usually sufficient for converting the signal from an audio source (like a microphone or tape recorder) into a .wav file that can be compressed for streaming. Encoder High-quality audio and video files can be very large. In order for the data to stream efficiently over the Internet to a range of targeted bandwidths, it must be compressed into small information packets. This compression is done with encoding software, often called an "encoder," such as RealSystem Producer. Note: RealSystem Producer Plus includes a bandwidth simulator that lets you see what your audience sees at each specified connection rate. Server "Server" can refer to both hardware and software. A server is a computer (hardware) that contains the files (sometimes called "content") to be delivered. This server also houses the technology (software) to deliver these files over a network such as the Internet. Player A player is any software application-such as RealPlayer-that receives streaming (digital) media from a Web or intranet server, decodes it and plays it back on your computer.
