ffmpeg -ss 565 -to 01:56:40 -i input.mpg -c:a copy -c:v libx264 -crf 18 -preset ultrafast -s 1280x720 -pix_fmt yuv420p -map 0:a? -map 0:v -ignore_unknown output.mkv

Explanation:

-ss 565: cut the first 565 seconds (time format can also be used I think)

-to 01:56:40: cut the movie at 1h56m40secs, discarding the rest

-crf 18: Higher values: smaller file, worse quality; lower values (e. g. 10): bigger file, higher quality.

-i input file

The resulting scaled file will be written to “output.mkv”.

Source:

https://superuser.com/questions/1527662/visually-lossless-1080p-to-720p-using-ffmpeg