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

Movie AtomsSample AtomsSizeA 32-bit integer that specifies the number of bytes in the partial sync sample atom.TypeA 32-bit integer that identifies the atom type; this field must be set to ‘stps’.VersionA 1-byte specification of the version of this atom.FlagsA 3-byte space reserved for flags. Set this field to 0.Entry countA 32-bit unsigned integer that specifies the number of sample numbers in the array that follows.Partial sync sample tableA table of sample numbers. Figure 2-44 (page 109) shows the layout of the partial sync sample table.Figure 2-44NumberNumberNumberNumberNumberThe layout of a partial sync sample tableSample 1Sample 2Sample 3Sample 4Sample 5Sample-to-Chunk AtomsAs samples are added to a media, they are collected into chunks that allow optimized data access. A chunkcontains one or more samples. Chunks in a media may have different sizes, and the samples within a chunkmay have different sizes. The sample-to-chunk atom stores chunk information for the samples in a media.Sample-to-chunk atoms have an atom type of 'stsc'. The sample-to-chunk atom contains a table that mapssamples to chunks in the media data stream. By examining the sample-to-chunk atom, you can determine thechunk that contains a specific sample.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.109