Ffmpegクロップスケールオーバーレイパラメーターの違い

Ffmpeg Crop Scale Overlay Parameter Difference

ビデオトリミングエリアのトリミング

w, out_w The width of the output video. It defaults to iw. This expression is evaluated only once during the filter configuration, or when the ‘w’ or ‘out_w’ command is sent. h, out_h The height of the output video. It defaults to ih. This expression is evaluated only once during the filter configuration, or when the ‘h’ or ‘out_h’ command is sent. x The horizontal position, in the input video, of the left edge of the output video. It defaults to (in_w-out_w)/2. This expression is evaluated per-frame. y The vertical position, in the input video, of the top edge of the output video. It defaults to (in_h-out_h)/2. This expression is evaluated per-frame. crop=w=100:h=100:x=12:y=34

スケールスケーリング

width, w height, h Set the output video dimension expression. Default value is the input dimension. If the width or w value is 0, the input width is used for the output. If the height or h value is 0, the input height is used for the output. If one and only one of the values is -n with n >= 1, the scale filter will use a value that maintains the aspect ratio of the input image, calculated from the other specified dimension. After that it will, however, make sure that the calculated dimension is divisible by n and adjust the value if necessary. If both values are -n with n >= 1, the behavior will be identical to both values being set to 0 as previously detailed. See below for the list of accepted constants for use in the dimension expression. scale=w=200:h=100 scale=w=iw/2:h=ih/2

オーバーレイビデオオーバーレイ

x y Set the expression for the x and y coordinates of the overlaid video on the main video. Default value is '0' for both expressions. In case the expression is invalid, it is set to a huge value (meaning that the overlay will not be displayed within the output visible area) overlay=0:0