Sound Media Information Header Atoms

QuickTime Movie File Format Specification, May 1996

The sound media information header atom (shown in Figure 0-24 ) stores the sound media's control information, such as balance.

Figure 24 The layout of a sound media information header atom

The sound media information header atom contains the following data elements.

Size: A 32-bit integer that specifies the number of bytes in this sound media information header atom.
Type: A 32-bit integer that identifies the atom type; this field must be set to ' smhd' .
Version: A 1-byte specification of the version of this sound media information header atom.
Flags: A 3-byte space for sound media information flags. Set this field to 0.
Balance: A 16-bit integer that specifies the sound balance of this sound media. Sound balance is the setting that controls the mix of sound between the two speakers of a computer. This field is normally set to 0. See Inside Macintosh: QuickTime for more information about QuickTime sound balance values.
Reserved: Reserved for use by Apple. Set this field to 0.