+/**
+ * Extract a afd stored in a shared memory area.
+ *
+ * Attach the shared memory area given by \a shmid, load the audio file data
+ * stored therein and detach the area afterwards. Called by vss, after
+ * receiving a positive response to the request for the next audio file.
+ +
+ * \param shmid The identifier of the shared memory area containing the afd.
+ * \param afd Result pointer.
+ *
+ * \return Standard.
+ */