QuickTime Player lets you receive streaming media delivered over the Internet. Streams can originate from a live source, such as a video camera, a webcast, or an audio feed from a radio station, or the source can be a QuickTime movie stored on the server. In either case, you aren’t downloading a file when you view a streamed movie. The data is simply being displayed as it arrives by the QuickTime plug-in and in QuickTime Player; no copy remains on the your hard disk.

QuickTime includes the latest advances in streaming technology giving you instant access to the media without having to wait for lengthy downloads or buffer times. With an end-to-end, standards-based solution, QuickTime streaming allows you to quickly and easily reach the widest range of customers whether they are on a Mac, Windows PC or mobile device.

End-to-end, standards-based solution

The QuickTime platform provides an end-to-end solution for media creation, delivery and playback. Based on standards, both QuickTime Streaming Server and QuickTime Player support the IETF standard RTP/RTSP streaming protocols for sending and receiving live and on-demand streaming media. With true live events, the stream functions more or less as the web version of a TV or radio broadcast; users can turn it on or off and switch to another channel but they will view the content wherever the broadcast happens to be. When you are streaming a completed movie stored on a hard disk (sort of a video-on-demand arrangement), your audience has random access to the entire stream and can jump anywhere within it.

Streaming Types

QuickTime currently supports several types of streaming. Unicast streams are simple one-to-one streams, like a phone call from the server to a single client computer. To reach many clients, the server must send many streams, which is a less efficient use of bandwidth. However, each viewer of a unicast stream can randomly access the movie, playing only the parts they want to see. Typically, unicast is used to stream prerecorded movies.

Multicast streams are sent directly to a group address, such an IP multicast address, which in turn can be simultaneously accessed by many client computers. The viewer of a multicast has no control over what is presented. Multicasts are an efficient way to deliver the same material to a group of people over a LAN, as only one copy of the stream is sent over the network.

Reflected multicast streams take live media from another source, such as a radio or TV broadcast, and stream it out to viewers as a series of unicasts. This is the approach taken by online news networks, such as CNN.com.

Real-time Streaming Versus Progressive Download

Progressive download allows users to watch or listen to media as it is being downloaded from a standard web server (such as Apache,) to their hard drive. This method works best for short-form media where file size is limited. Progressive download ensures high-quality playback regardless of users' Internet connection speed, although users with slower connections will wait longer before media starts to play.

Real-time streaming using QuickTime Streaming Server delivers media in real time over the Internet, from modem to broadband rates.With the open standard Real-Time Transport Protocol/Real-Time Streaming Protocol (RTP/RTSP), no file is ever downloaded to a viewer's hard drive. Media is played, but not stored, by the client software as it is delivered. Real-time streaming is often preferable to progressive download for webcasts of live events, delivery of long-form video, and 24/7 Internet radio and TV channels.

Why QuickTime Streaming?

Choosing to stream QuickTime is choosing to stream reliably. With patent-pending quality of service features like Skip Protection and Instant-On, QuickTime Player and QuickTime Streaming Server make sure that you viewers have the optimal streaming experience regardless of network congestion.

Skip Protection

Skip protection is Apple's patent-pending technology for preventing interruptions or skips in streaming. Skip Protection works by taking advantage of excess bandwidth to buffer ahead data faster than real time on the client computer. If packets are lost, communication between client and server results in retransmission of only the lost packets, reducing the impact on network traffic. By buffering ahead a high-quality "copy"of the media, QuickTime Streaming Server delivers a smooth, high-quality media stream time after time.

Instant-On

Instant-On streaming gives users an immediate and smooth playback experience for real-time streams - and instant access as you jump or "scrub" through a movie using the time slider. An advancement in Apple's Skip Protection technology, a patent-pending streaming technology that prevents skips or interruptions in streams due to network congestion, Instant-On changes the way you experience streaming media.

Advantages of Streaming

• Instant play
• Deliver long form media
• Deliver live broadcasts
• Multicasts (one stream to many viewers)
• Eliminates the need to download files to the hard drive
• Distribution control
• Can stream individual tracks into a movie from any streaming server anywhere