Quicktime File Format (2012-08-14).pdf

Movie AtomsTrack AtomsSizeA 32-bit integer that specifies the number of bytes in this track input map atom.TypeA 32-bit integer that identifies the atom type; this field must be set to 'imap'.Track input atomsA list of track input atoms specifying how to use the input data.The input map defines all of the track’s secondary inputs. Each secondary input is defined using a separatetrack input atom.Each track input atom contains the following data elements.SizeA 32-bit integer that specifies the number of bytes in this track input atom.TypeA 32-bit integer that identifies the atom type; this field must be set to ' in' (note that the two leadingbytes must be set to 0x00).Atom IDA 32-bit integer relating this track input atom to its secondary input. The value of this field correspondsto the index of the secondary input in the track reference atom. That is, the first secondary inputcorresponds to the track input atom with an atom ID value of 1; the second to the track input atom withan atom ID of 2, and so on.ReservedA 16-bit integer that must be set to 0.Child countA 16-bit integer specifying the number of child atoms in this atom.ReservedA 32-bit integer that must be set to 0.The track input atom, in turn, may contain two other types of atoms: input type atoms and object ID atoms.The input type atom is required; it specifies how the data is to be interpreted.The input type atom contains the following data elements.SizeA 32-bit integer that specifies the number of bytes in this input type atom.TypeA 32-bit integer that identifies the atom type; this field must be set to ' ty' (note that the two leadingbytes must be set to 0x00).2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.77