describe their actions

You not supposed to do anything while meditating, that's what makes it meditating. Just clear your thoughts and calm your mind and heart, and become aware of your surroundings. It's good to meditate while sitting in a lotus position. You can repeatedly chant the 'Ohm' mantra if you want. If you chose to "Ohm" feel as your body vibrate with each "Ohm". Really concentrate on your breathing. Breath with your diaphragm, slowly, and through your nose. Really take in your surroundings and the universe. Meditation is best done in a location you feel is peaceful.

sometimes during meditation, I briefly appear as video images during sleep, in which I can look at everything down to small details, it seems to me that I fall asleep. I'm on the right track? sorry for the Google translation, I do not know much English

Same happens to me, when i meditate in bed at the night, Suddenly after i don't know what time it happens i suddenly see me doing something or others like and image i just suddenly see it and then fall asleep and wakes up next day, and its weird how i remember the image of what i saw.