VideoWriter YUV RAW video encoding error (Bug #1413)

In revision 5569, Raw video encoding format has been changed due to several user requests (codec_pix_fmt has been set to input_pix_fmt for CODEC_ID_RAWVIDEO case).

But when I'm trying to record a video from my camera in YUV Raw format (IYUV fourcc for example), the video is encoded in BGR24 and when I'm trying to read it with mplayer, it reads it as YUV format and output video is distorted. On standard output when trying with IYUV fourcc, I get this.

Output #0, avi, to 'foo.avi':
Stream #0.0: Video: rawvideo, bgr24, 640x480, q=2-31, 19660 kb/s, 90k tbn, 30 tbc

In cap_ffmepg.ccp, when recording in YUV format with RGB input, we should not use input fourcc but still do codec_pix_fmt = PIX_FMT_YUV420P when input format is different as output format for YUV output.