Try using this. It is the fastest and best ffmpeg-way I have figure it out:
ffmpeg -ss 00:01:00 -i input.mp4 -to 00:02:00 -c copy output.mp4
This command trims your video in seconds!
Explanation of the command:
-i: This specifies the input file. In that case, it is (input.mp4).
-ss: Used with -i, this seeks in the input file (input.mp4) to position.
00:01:00: This is the time your trimmed video will start with.
-to: This specifies duration from start (00:01:40) to end (00:02:12).
00:02:00: This is the time your trimmed video will end with.
-c copy: This is an option to trim via stream copy. (NB: Very fast)
The timing format is: hh:mm:ss
ffmpeg -i movie.mp4 -ss 00:00:03 -t 00:00:08 -async 1 -c copy cut.mp4
Use -c copy for make in instantly. In that case ffmpeg will not re-encode video, just will cut to according size.