Sample-to-chunk atom ('stsc')
An atom that stores chunk information for the samples in a media.
Overview
As samples are added to a media, they are collected into chunks that allow optimized data access. A chunk contains one or more samples. Chunks in a media may have different sizes, and the samples within a chunk may 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 maps samples to chunks in the media data stream. By examining the sample-to-chunk atom, you can determine the chunk that contains a specific sample.
The layout of the sample-to-chunk atom is as follows.
Sample-to-chunk atom data field | Bytes |
|---|---|
4 | |
Type = | 4 |
1 | |
3 | |
4 | |
Variable |
Topics
Data fields
See Also
Describing samples
Sample table atom ('stbl')Seeking with a QuickTime fileSample description atom ('stsd')Time-to-sample atom ('stts')Creating video tracks at 30 frames per secondCreating video tracks at 29.97 frames per secondCreating sound tracks at 44.1 kHzComposition offset atom ('ctts')Composition shift least greatest atom ('cslg')Using composition offset and composition shift least greatest atomsSync sample atom ('stss')Partial sync sample atom ('stps')Referencing two data files with a single trackSample size atom ('stsz')Chunk offset atom ('stco')