an MPEG playback card, and (on Windows) a driver for the MPEG card are in place.
QuickTime for the Macintosh has a media handler for MPEG that reads MPEG files and forwards them to the video-stream player. The player then looks for hardware to decompress and play the MPEG file. At present, the hardware it looks for is the Wired card (Wired can be reached at D0024@applelink.apple.com) and/or an Apple card.
QuickTime for Windows also supports MPEG, but the driver that comes with the MPEG card must support the Open MPEG Standard fully, which includes being able to read from a buffer (many cards only implement reading from a file). The latest drivers for the Sigma Real Magic card work, but you need to contact Sigma to make sure you have the ones that work with QuickTime for Windows.
If you need low-level details on MPEG stream players, you can get this information from the QuickTime Conferencing SDK. There is also some code-level documentation on the QuickTime 2.0 SDK CD.
MPEG files are opened directly by QuickTime using the import mechanism that has been present since QuickTime 1.5. MPEG files can be opened using the normal OpenMovieFile, NewMovieFromFile, CloseMovieFile sequence. The QuickTime Movie is generated on the fly. MPEG movies do not contain sound or video tracks. In their place is a single track, handled by the MPEG Media Handler. This media handler has both video and audio components. Movies containing MPEG work with any application that supports standard QuickTime playback.
There are some differences with how MPEG is handled that may effect applications which provide more extensive editing support than the standard Movie Controller. MPEG movies can be edited using normal editing commands. However, the sample format is extremely different. A typical MPEG track has only one giant sample, which makes working with calls like GetMediaSample impractical. There is not currently an export component which allows a QuickTime-edited MPEG movie to be turned back into a pure MPEG stream. Some MPEG hardware does not support any access to the MPEG image data. This means that the track cannot be imaged off screen, and that calls like GetMoviePict may fail.
MPEG playback currently requires special hardware. All known hardware only supports playback of one MPEG stream at a time. This means that if two MPEG movies are open at the same time, only one can play. The MPEG Media Handler moderates as best it can, much as the Sound Media Handler moderates the distribution of sound channels when using Sound Manager 2.0.
MPEG data can either be embedded in a QuickTime movie or stored in standard MPEG file (a standard MPEG file is a text file with the extension .MPG). If you open a standard MPEG file, QuickTime creates the movie automatically.
QuickTime can also play MPEG movies stored on CDi disks. For some CDi disks, it
may be necessary to use the most recent Apple CD-ROM software, which is
provided on the QuickTime 2.0 SDK in the Extensions folder.