Transform

$ ffmpeg -i input.mkv -map_metadata -1 -c:v libx264 -b:v 4096k -c:a libmp3lame -b:a 320k output.mp4

File Format

$ ffmpeg -i input.mkv -c:v copy -c:a copy output.mp4

Capture JPEG Image

$ ffmpeg -i input.mp4 -ss 00:00:05 -r 1 -vframes 1 -an -vcodec mjpeg output.jpg

Split

$ ffmpeg -i input.mp4 -ss 00:00:30 -t 00:00:10 -c copy output.mp4

Resolution

$ ffmpeg -i input.mkv -s 1280x720 -c copy output.mp4

Crop

$ ffmpeg -i input.mp4 -filter:v crop=1920:890:0:95 -c copy output.mp4

Merge

$ echo -ne "file 'part01.flv'\nfile 'part02.flv'\n" > inputs.txt
$ ffmpeg -f concat -i inputs.txt -c copy output.flv