Error when I use aforge FFMPEG

See more:

C#

webcam

ffmpeg

hi guy's
i use Aforge lib in my project for capture image and record live video from webCam ...
but when use ffmpeg.dll to save AVI file from webCam send this Error :

private VideoFileWriter FileWriter = new VideoFileWriter();
        FileWriter.Open("test.avi", 460, 500, 25, VideoCodec.Default, 5000000);
            img = (Bitmap)videoSourcePlayer.GetCurrentVideoFrame().Clone();
        FileWriter.WriteVideoFrame(img);

Error img :

[^]

how to handle this error ?
thanks

What I have tried:

how to handle this error ?
i don't know work