Shuffle video frame
打乱视频帧
可打乱视频内局部区域
打乱单元可为矩形，边长需要满足：打乱区域边长被单元边长整除
具体效果见 Bilibili视频
详细例子见 VideoShuffle.Example
using Myitian.Shuffling;
using System.Drawing;
XShuffle xs = new XShuffle();
VideoShuffle vs = new VideoShuffle(new Size(1920, 1080), new Rectangle(0, 0, 120, 1080), new Size(120, 120));
byte[] buffer;
// ... read ffmpeg stdout, store a rawvideo frame in buffer ...
Frame frame = vs.LoadFrame(buffer); // load frame info
xs.Shuffle(frame); // shuffle frame
// ... write buffer to ffmpeg stdin ...