How did people turn harvested rice into rice in history?

After the mouth is cracked, take a bundle and hit it on the stone, and the rice will flow down ~ ~?

I have also seen a kind of rice called Chun, Baidu Encyclopedia-

Rice? What is in the rice? mǐ？

Meaning: Inverting rice is the process of shelling the fallen millet. The shelled rice is rice bran, and the remaining rice grains are white rice I ate. The tool for pounding rice is a bit like a medicine pot, with a wooden stick and a container. Smash millet and rice bran with a wooden stick.