-b:v 2600kto change video bitrate
-hide_bannerto remove configuration build options
-filter:v "setpts=0.5*PTS"to double speed (halving the presentation timestamp of a frame)
pause(to bring to the background) then
fgto bring the process back to life and continue encoding
-filter:v "crop=720:420:0:450"following the format "crop=out_w:out_h:x:y"
-ss 5 -t 25, especially important to test without wasting time
My notes on Tools gather what I know or want to know. Consequently they are not and will never be complete references. For this, official manuals and online communities provide much better answers.