ffmpeg -f lavfi -r 10 -i \
  "nullsrc=s=500x500,geq=lum='mod(ceil(log(mod(T*4,1)*Y*X*(2+ sin(T)))),8)*32' [x1];
   nullsrc=s=500x500,geq=r='mod(ceil(log(mod(T*2,1)*Y+X*(2+ cos(-T)))),4)*64' [x2];
   [x1][x2] blend=all_mode=xor,
     trim=duration=0.25,
     scale=s=360x360" -y -an 0141.gif