Depends what you're filming in. If you are just filming in 240p or something ridiculous like that then it won't take long at all. But if like me you film in full 1080p then it will take a long time. What youtube does with hi res video is make a separate copy of your video for each resolution. So when you watch a video that gives you different resolutions available, essentially they are separate videos. This process can take a long time. You can use a program called handbrake which strips out some stuff from the video before you upload, it drastically reduces the file size. I stopped using it because I've noticed it gives my videos a weird haze like I'm in some sort of 90's sitcom. But you might have better luck. My videos are normally around 3 or 4 gb if I haven't used handbrake, and takes around 3-4 hours to upload.