C++ (Qt)
enum ObjectType { PcmObjectType, Ac3ObjectType };
enum Direction { InputDirection, OutputDirection };
 
class Object
{
public:
    virtual void print() = 0; 
}
 
// PCM objects
 
class PcmObject : public Object
{
public:
    PcmObject() { /* init a common PCM features */ }
}
 
class PcmInputObject : public PcmObject
{
public:
    PcmInputObject() { /* init a specific PCM Input features */ }
    void print() { /* I am PcmInputObject */} 
}
 
class PcmOutputObject : public PcmObject
{
public:
    PcmOutputObject() { /* init a specific PCM Output features */ }
    void print() { /* I am PcmOutputObject */} 
}
 
// AC3 objects
 
class Ac3Object : public Object
{
public:
    Ac3Object() { /* init a common AC3 features */ }
}
 
class Ac3InputObject : public Ac3Object
{
public:
    Ac3InputObject() { /* init a specific AC3 Input features */ }
    void print() { /* I am PcmInputObject */} 
}
 
class Ac3OutputObject : public Ac3Object
{
public:
    Ac3OutputObject() { /* init a specific AC3 Output features */ }
    void print() { /* I am Ac3OutputObject */} 
}
 
// factories
 
class AbstractFactory
{
public:
    virtual Object *create(Direction dir) = 0;
}
 
class PcmFactory : public AbstractFactory
{
public:
    Object *create(Direction dir) {
        switch (dir) {
        case InputDirection: return new PcmInputObject;
        case OutputDirection: return new PcmOutputObject;
        default: return 0;
        }
    }
}
 
class Ac3Factory : public AbstractFactory
{
public:
    Object *create(Direction dir) {
        switch (dir) {
        case InputDirection: return new Ac3nputObject;
        case OutputDirection: return new Ac3OutputObject;
        default: return 0;
        }
    }
}
 
// factory creator
 
class FactoryCreator
{
public:
    AbstractFactory *create(ObjectType objectType) {
        switch (objectType) {
        case PcmObjectType: return new PcmFactory;
        case Ac3ObjectType: return new Ac3Factory;
        default: return 0;
        }
    }
}
 
// usage
 
void main()
{
    // received the some initial properties from an some data source
    ObjectType objectType = PcmObjectType;
    Direction direction = OutputDirection;
 
    // need create a desired object from a properties
    FactoryCreator fc;
    AbstractFactory *factory = fc.create(objectType);
    Object *obj = factory->create(direction);
    obj->print();
 
    return 0;
}