Document Revision History

First public release of complete, updated QuickTime File Format Specification with information about atoms and atom types. Added licensing information and disclaimer for developers. Modified introductory sections and atom descriptions; updated artwork and edited for technical accuracy.

A QuickTime file may now contain a file type compatibility atom. See “The File Type Compatibility Atom.” A movie atom may now contain a movie profile atom. See “The Movie Profile Atom.” A track atom may now contain a track profile atom. See “Track Profile Atom.” Video sample descriptions may now contain a pixel aspect ratio atom for non-square pixels. See “Pixel Aspect Ratio ('pasp').” Video sample descriptions may now also contain a color parameter atom. See “Color Parameter Atoms ('colr').” Video sample descriptions may now a clean aperture atom. See “Clean Aperture ('clap').” The sound description record has been expanded to represent variable bit-rate compression more accurately. See “Sound Sample Descriptions.” The section describing MPEG-4 audio has been modified. See “MPEG-4 Audio.”

It is now recommended that the file creation and modification times be set using UTC, rather than local time zones. See “Calendar Date and Time Values.” User data text may now be encoded using either Macintosh text encoding or ISO text encoding (Unicode). See “User Data Text Strings and Language Codes.” MPEG-4 video and audio sample descriptions may now contain elementary stream descriptor atoms. See “MPEG-4 Elementary Stream Descriptor Atom ('esds')” and “MPEG-4 Elementary Stream Descriptor ('esds') Atom.” It is now possible to specify languages using either Macintosh language codes or ISO language codes. See “Language Code Values.”