I used this command
ffmpeg -i thevideo.mp4 -c:a copy -vf 'drawbox= : x=0 : y=0 : color=invert:enable=between(t\,11\,39)' output.mp4 but it runs very slow.
So, I took another approach, I copy first and last part and run "drawbox" only on selected length, and then adding them all together.
ffmpeg -i thevideo.mp4 -ss 00:00:00 -to 00:00:10 -c copy cut.mp4 ffmpeg -i thevideo.mp4 -ss 00:00:11 -to 00:00:39 -c:a copy -vf 'drawbox= : x=0 : y=0 : color=invert' cut2.mp4 ffmpeg -i thevideo.mp4 -ss 00:00:40 -c copy cut3.mp4 ffmpeg -f concat -i mylist.txt -c copy output.mp4
file 'cut1.mp4' file 'cut2.mp4' file 'cut3.mp4'
Can I run it in one command and have the same speed or even faster but without cutting and concatenating the parts of the video?