AForge.Video.FFMPEG.VideoFileWriter videoWriter = new AForge.Video.FFMPEG.VideoFileWriter();

videoWriter.Open(mp4file, width, height, 10, AForge.Video.FFMPEG.VideoCodec.MPEG4);

重點來了，如果你是通過像素分析方式獲得的屏幕寬度和高度，請注意width和height必須是偶數(shù)!