slow and memory problem 

I have 2 problems actually
Firstly, the code takes a very long time to process the video
The second is that during the processing process, it requires a huge amount of memory, which reached a limit of 18 GB, which led to the storage memory becoming full and the program stopping.
the video that i work on is 2 hour lecture with size 1.3 g
128 ssd for C drive, win 10 64, 4 g ram 