I jus need to open the source video, mark the start and end points and cut that part. It shouldn't convert the file or it shouldn't re-encode the file. Jus cut. No cropping, no resolution changing, no format changing.And then join 2 or 3 video cuts into one. Is there any software does these?? Almost all my source videos are mp4 and mkv. I tried like 10+ softwares listed by Google and failed to achieve what I want, would really appreciate if someone comes up with the right piece of software. Thx in advance.