在视频上实现字幕叠加,在每个视频帧上输出标准的字符串，以合成新的图像帧，通过GDI绘图实现，有详细的代码说明文档-Superimposed on the video to achieve in each video fr a me on the output of a standard string, to synthesize a new image fr a me, drawing achieved by GDI, a detailed code documentation