利用 ffmpeg 的 maskedmerge 滤镜, 从视频中提取移动对象

ffmpeg 
   -i background.png 
   -i video.mkv 
   -filter_complex 
   "
      color=#00ff00:size=1280x720 [matte];
      [1:0] format=rgb24, split[mask][video];
      [0:0][mask] blend=all_mode=difference, 
         curves=m='0/0 .1/0 .2/1 1/1', 
         format=gray,
         smartblur=1,
         eq=brightness=30:contrast=3, 
         eq=brightness=50:contrast=2, 
         eq=brightness=-10:contrast=50,
         smartblur=3,
         format=rgb24 [mask];
      [matte][video][mask] maskedmerge,format=rgb24
   " 
   -shortest 
   -pix_fmt yuv422p 
   result.mkv