Lecturer said he have teach too fast. If I'm not mistaken he had teach till chapter 4 the day i didnt attend the class. He showed us video clips made by the previous sem. To give some advice of Do's and Don'ts. Some videos were great and some were okay.

Do's
Clear voice
Subtitle
Formal language
Really into the title instead of out of topic
Be creative
Clear image

Don't
Unnessary scene
Out of topic
Unclear video
Complicated concept