ClassData Functions

All plugin types that support media can use these callbacks to share information associated with their classID.

For example, these plugins can confirm their hardware is present and operational using the ClassData functions.

They all call getClassData during initialization. If getClassData returns 0, the module checks for and initialize the hardware.

It then calls setClassData to store information about the current context. Use handles, not pointers, for storing info.

typedef struct {
  SetClassDataFunc  setClassData;
  GetClassDataFunc  getClassData;
} ClassDataFuncs, *ClassDataFuncsPtr;

Methods

setClassData

Writes class data, destroys previous data.

Note that all plugins that share the data must use the same data structure.

int setClassData (
    unsigned int  theClass,
    void          *info);

Parameter	Type	Description
`theClass`	Unsigned int	The class being set. Use a unique 4-byte code.
`info`	Pointer or handle	the class data to be set. It can be used as a pointer or a handle.

getClassData

Retrieves the class data for the given class.

int getClassData (
    unsigned int  theClass);

Parameter	Type	Description
`theClass`	Unsigned integer	The class for which to retrieve data.