H.264 is an MPEG-4 codec for high-quality video over a range of bandwidths, whether 3G mobile devices, video conferencing, DVD or broadcast quality HD TV. It has been adopted by both the Blu-ray Disc Association, of which Apple is a member, and the DVD Forum for use in next-generation high-definition DVDs. QuickTime also supports two dozen of the popular video and graphics formats and a dozen audio formats.
QuickTime 7 Player can play up to 24 audio channels, including 5.1 and 7.1 surround sound, with new playback controls, including variable playback speed, jog shuttle, so you can adjust the speed at which you search through individual movie frames, and live resizing of the viewer window. It also features zero-configuration streaming for optimum stream quality and new AV controls to adjust audio balance and volume, bass and treble response, brightness, colour, contrast and tint.
Apple recommends that you use QuickTime 7 for Windows Public Preview only for testing purposes. Additionally, it is not recommended that you try using it with other QuickTime-based applications, such as iTunes.