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

Movie AtomsSample AtomsEntry countA 32-bit unsigned integer that specifies the number of sample numbers in the array that follows.Following the entry count is a composition-offset table, shown in Figure 2-39 (page 105).Figure 2-39The layout of a composition-offset table entrySampleCountcompositionOffsetField4 4BytessampleCountA 32-bit unsigned integer that provides the number of consecutive samples with the calculatedcomposition offset in the field.compositionOffsetA 32-bit signed integer indicating the value of the calculated compositionOffset.Composition Shift Least Greatest AtomThe optional composition shift least greatest atom summarizes the calculated minimum and maximum offsetsbetween decode and composition time, as well as the start and end times, for all samples. This allows a readerto determine the minimum required time for decode to obtain proper presentation order without needing toscan the sample table for the range of offsets. The type of the composition shift least greatest atom is ‘cslg’.Figure 2-40 (page 105) shows the layout of this atom.Figure 2-40The layout of a composition shift least greatest atomBytesComposition Shift Least Greatest atomAtom sizeType = 'cslg'VersionFlags4413compositionOffsetToDisplayOffsetShift 4leastDisplayOffset 4displayStartTime 4displayEndTime 42012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.105