audio_file
struct audio_file *file;
SLIST_REMOVE(&sc->sc_files, file, audio_file, entry);
SLIST_REMOVE(&sc->sc_files, file, audio_file, entry);
SLIST_REMOVE(&sc->sc_files, af, audio_file, entry);
SLIST_REMOVE(&sc->sc_files, file, audio_file, entry);
SLIST_ENTRY(audio_file) entry;
SLIST_HEAD(, audio_file) sc_files;
typedef struct audio_file audio_file_t;
struct audio_file *fd_audioctx; // DTYPE_MISC (audio)
struct audio_file af;