A 45 minute video is a HUGE file, in the neighborhood of 5 Gig. It would take SERIOUS computing power with tons of memory to handle that. As BEF suggested, take shorter videos. The last video I took was 12 seconds long and was 22 meg in size.
The 45 minute video is from my phone. I mounted it on a tripod, that I set up to video my tractor cleaning up some trees. I just let the phone record while I'm working, and it's a surprise to see what I get. Most of it is worthless.
In the end, and after combining it with a few other videos, the finished video is under one minute.