What's your problem?
You want to remove or extract a part of a video.
You could download, install and/or buy some advanced editing software which has such feature (like Adobe Premiere Pro), but it takes a lot of time and energy, especially if you are working with several, long videos and the software has to decodes and re-encodes the files every time.
The solution : FFmpeg....
Work expands so as to fill the time available for its completion
In other words, if you have a certain amount of time to complete something, that’s how long it will generally take.
Anything that can go wrong, will go wrong (at the worst possible time)
Most ideas look great on paper. But by the time events go from A all the way through the alphabet to Z, you see who rules when it comes to getting something from the theoritical stage to the practical stage : it's Murphy's Law.
No battle plan survives first contact with the enemy. Hope for the best, be ready for the worst....
There are some people who are willing to sacrifice almost everything, including their time, resources, sometimes even their social life, their sleep and some "normal" pleasures of life. All of that, in order to work hard and focus on their vocation, to improve things or try and make their world a slightly better place. Your grandparents had a word for that: Saints. Today we refer to them as Entreprenerds....
Quite amazing... Beauty of Math :
1 x 8 + 1 = 9
12 x 8 + 2 = 98
123 x 8 + 3 = 987...