QuickTime 5, QuickTime 6, and QuickTime 7 include support for the following:
- MPEG-1 playback on Mac and Windows computers
- Layer 1 and 2 audio support
- Support for elementary and muxed streams
- Enabling of frame-accurate access and effects compositing
The optional QuickTime MPEG-2 Playback Component provides QuickTime 7 users with the ability to import and play back MPEG-2 content, including both multiplexed content (muxed content, where the audio and video tracks are interleaved together into one track) and non-multiplexed (elementary) streams.
The QuickTime MPEG-2 Playback Component is unnecessary and can't be installed in OS X Lion or later, which includes built-in MPEG-2 functionality.
It isn't possible to export the audio portion of a muxed MPEG-1 or MPEG-2 audio/video stream using QuickTime. For editing purposes, the entire MPEG-1 or MPEG-2 stream is treated as a single sample. You may create edit lists to display parts of the stream in the usual way, but if you flatten the movie data, the entire stream is saved, not just the parts displayed in the movie.
You can't perform editing functions such as Cut, Copy, Paste, Add, and Add Scaled with MPEG-1 or MPEG-2 media using QuickTime Player, whether or not you have upgraded to QuickTime Pro. You may want use a third-party utility to convert the muxed file to a format that does allow you to edit or export.