int  initGIF(char ***mime_types, int *nrtypes, float **prefs);
  int  openGIF(const W3ADocumentInfo doc,  Widget  window, long id);
 int writeGIF(long id, const char *buf, size_t nbytes);
  int  closeGIF(long id);
 void eventGIF(long id, long source, long eventtype, void *params);
  int  infoGIF(long id, W3ADocumentInfo *doc);