+struct LIBARDOUR_API AudioBackendInfo {
+ const char* name;
+
+ /** Using arg1 and arg2, initialize this audiobackend.
+ *
+ * Returns zero on success, non-zero otherwise.
+ */
+ int (*instantiate) (const std::string& arg1, const std::string& arg2);
+
+ /** Release all resources associated with this audiobackend
+ */
+ int (*deinstantiate) (void);
+
+ /** Factory method to create an AudioBackend-derived class.
+ *
+ * Returns a valid shared_ptr to the object if successfull,
+ * or a "null" shared_ptr otherwise.
+ */
+ boost::shared_ptr<AudioBackend> (*factory) (AudioEngine&);
+
+ /** Return true if the underlying mechanism/API has been
+ * configured and does not need (re)configuration in order
+ * to be usable. Return false otherwise.
+ *
+ * Note that this may return true if (re)configuration, even though
+ * not currently required, is still possible.
+ */
+ bool (*already_configured)();
+
+ /** Return true if the underlying mechanism/API can be
+ * used on the given system.
+ *
+ * If this function returns false, the backend is not
+ * listed in the engine dialog.
+ */
+ bool (*available)();
+};
+
+class LIBARDOUR_API AudioBackend : public PortEngine {