AFEW trainset acc calculate

[HBen]

hallo , i read you code then i am confuse about the acc calculate procee in your code,there is some question:
it is use a matrix shape （380, number of images）--m1，to multiple the (number of images , 7 )--m2 get the (380,7) --m3and seems think it's the video result of the module predict. i check the m1,this a index metrix, it's seems means images belong the video index in the videolist. it's True/False. i still confuse why need to multiply, and what is mean.
Tanks very much