QuickTime Music Architecture

Knob Description Structure

A knob description structure contains sound parameter values for a single knob. It is defined by the KnobDescription data type.



 
struct KnobDescription {

    Str63                       name;

    long                        lowValue;

    long                        highValue;

    long                        defaultValue;

    long                        flags;

    long                        knobID;

};

typedef struct KnobDescription KnobDescription;

name: The name of the knob.
lowValue: The lowest number you can set the knob to.
highValue: The highest number you can set the knob to.
defaultValue: A value to use for the default.
flags: Various information about the knob. See "Knob Flags" [link] .
knobID: A knob ID or index. A nonzero value in the high byte indicates that it is an ID. The knob index ranges from 1 to the number of knobs; the ID is an arbitrary number. Use the knob ID to refer to the knob in preference to the knob index, which may change.