Creating sound tracks at 44.1 kHz

Overview

The duration of an audio sample is stored in the time-to-sample atom contained in a sample table atom. This duration cannot be interpreted without the media’s time scale, which defines the units per second for the duration. With audio, the duration of each audio sample is typically 1, so the time-to-sample atom has one entry, which applies to all audio samples.

With a time scale of 44100 in the media header atom, the time-to-sample atom would contain the data values listed in the following table.

This atom does not indicate whether the audio is stereo or mono or whether it contains 8-bit or 16-bit samples. That information is stored in the sound sample description atom, which is contained in the sample table atom.

See Also

Describing samples

• Sample table atom ('stbl')
• Seeking with a QuickTime file
• Sample description atom ('stsd')
• Time-to-sample atom ('stts')
• Creating video tracks at 30 frames per second
• Creating video tracks at 29.97 frames per second
• Composition offset atom ('ctts')
• Composition shift least greatest atom ('cslg')
• Using composition offset and composition shift least greatest atoms
• Sync sample atom ('stss')
• Partial sync sample atom ('stps')
• Sample-to-chunk atom ('stsc')
• Referencing two data files with a single track
• Sample size atom ('stsz')
• Chunk offset atom ('stco')