如何用ffmpeg 去除当前目录下的所有视频的多处水印?

kli

for %a in ("*.mp4") do ffmpeg -y -i "%a" -s 1280x720 -r 25 -b 400k -ab 64k -vf delogo=x=1050:y=402:w=212:h=49 "%~na_delogo.m4v"