This patch makes output codec keeping input pix_fmt value when using

stream_copy
patch by (Baptiste COUDURIER <baptiste@coudurier.smartjog@com>)

Originally committed as revision 5017 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffmpeg.c

@@ -1661,6 +1661,7 @@ static int av_encode(AVFormatContext **output_files,
                 codec->block_align= icodec->block_align;
                 break;
             case CODEC_TYPE_VIDEO:
+                codec->pix_fmt = icodec->pix_fmt;
                 codec->width = icodec->width;
                 codec->height = icodec->height;
                 codec->has_b_frames = icodec->has_b_frames;