QuickTime File Format change log

Changes to the QuickTime File Format.

Overview

Updated the color atom ('colr') to include information on new color standards, including DCI P3, P3 D65, and ITU-R BT.2020.

A new facility for timed metadata tracks has been incorporated, see Timed metadata media. Introduce 'cdsc' track reference type, see Track reference type atom. Added more well-known metadata data types, see Type indicator.

Corrected the values for kQTSampleDependency_OtherSamplesDependOnThisSample and kQTSampleDependency_-NoOtherSampleDependsOnThisSample.

In User data atoms, expanded the description of 'tnam' and added 'tagc' with related section Media Characteristic Tags.
Explained alternate groups in Alternate group.
Corrected structure of gmhd and gmin in Base media information atom ('minf').
General Structure of a Sample Description in Sample description atom ('stsd') includes emphasized importance of data size due to occasional terminating zeroes.
Timecode media information atom ('tcmi') now documents the reserved integer after the text size.
“Audio track” changed to “sound track” for consistency.

The sound sample description v2 format along with the definition of two new sound sample description extensions, see Sound sample description version 2 ('stsd').
New atoms for the display of track aperture in different modes, see Track aperture mode dimensions atom ('tapt').
New sample atoms for handling out-of-order movie samples, see Sample atoms.
Audio priming-handling encoder delay in AAC, which treats how to handle temporal positioning of AAC audio data explicitly.

The Macintosh language codes table has been updated with current language names, see Language code values and the related Extended language tag atom ('elng') defined.

Corrected the order of fields described in the Metadata handler atom ('hdlr') structure.

Added description of clip-based metadata and specific key/value pairs for location metadata.

First public release of complete, updated QuickTime File Format Specification with information about atoms and atom types.
Added licensing information and disclaimer for developers.
A QuickTime file may now contain a file type compatibility atom. See File type compatibility atom ('ftyp').
A movie atom may now contain a movie profile atom. See Movie profile atom ('prfl').
A track atom may now contain a track profile atom. See Track profile atom ('prfl').
Video sample descriptions may now contain a pixel aspect ratio atom for non-square pixels. See Pixel aspect ratio ('pasp') ('pasp').
Video sample descriptions may now also contain a color parameter atom. See Color parameter atom ('colr') ('colr').
Video sample descriptions may now a clean aperture atom. See Clean aperture ('clap') ('clap').
MPEG-4 video and audio sample descriptions may now contain elementary stream descriptor atoms. See MPEG-4 elementary stream descriptor atom ('esds') ('esds') and MPEG-4 elementary stream descriptor atom ('esds') ('esds').

Modified introductory sections and atom descriptions; updated artwork and edited for technical accuracy.
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 in Sound sample data.
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 in User data atoms.
It is now possible to specify languages using either Macintosh language codes or ISO language codes. See Language code values.