usx2y_iso_frames_per_buffer
usx2y_iso_frames_per_buffer(runtime, usx2y);
while (usx2y_iso_frames_per_buffer(runtime, usx2y) >
usx2y_iso_frames_per_buffer(runtime, usx2y),
usx2y_iso_frames_per_buffer(runtime, usx2y),