Erratic Camera Movement Effect Using Crop Filter

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The following example is based on the crop filter Examples section.

For input, we use the testsrc video generator to generate a 30s 720p video at 30 fps, and apply a crop filter to it.

The crop filter takes 4 parameters (w,h,x,y):

  • w: The width of the crop
  • h: The height of the crop
  • x: The x point on the width axis where the crop should start
  • y: The y point on the height axis where the crop should start

In this example, for the X and Y point, we use a dynamic point based on the t (timestamp) param and the sin function. Since the Sine ƒx returns a value between -1 and 1, this generates movement in the coordinates of where the x and y crop point.

ffmpeg -f lavfi -i testsrc=duration=30:size=1280x720:rate=30 -vf 'crop=in_w/2:in_h/2:(in_w-out_w)/2+((in_w-out_w)/2)*sin(t*1.25):(in_h-out_h)/2 +((in_h-out_h)/2)*sin(t*1.625)' -c:v libx264 -q:v 1 output.mp4