How to control the video buffering

I have inteet speed with 100 mbps with data usage of 30 GB.

Problem: Since my speed is high, video gets streamed completely. But I won't watch the complete video, I just watch few technical tips and close. So my data gets wasted. Is there anyway where we can could control the streaming manually?

Actual Problem with brief description:

I'm going through a technical class on adobe flash player. I' viewing it online, this video is about 4 hours but actual class is only for 3 hours. Remaining one hour video is just a ideal screen. So, problem is ,if i'm viewing the video for 3 hours, full 4 hours video gets buffered. I want to control this video buffering manually. Is it possible? I tried googling, but it say there is no possible solution for this problem