ffserver: allow choosing the pixel format

Fixes Ticket2954
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

ffserver.c

@@ -48,6 +48,7 @@
 #include "libavutil/dict.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/mathematics.h"
+#include "libavutil/pixdesc.h"
 #include "libavutil/random_seed.h"
 #include "libavutil/parseutils.h"
 #include "libavutil/opt.h"
@@ -4425,6 +4426,14 @@ static int parse_ffconfig(const char *filename)
                     video_enc.time_base.den = frame_rate.num;
                 }
             }
+        } else if (!av_strcasecmp(cmd, "PixelFormat")) {
+            get_arg(arg, sizeof(arg), &p);
+            if (stream) {
+                video_enc.pix_fmt = av_get_pix_fmt(arg);
+                if (video_enc.pix_fmt == AV_PIX_FMT_NONE) {
+                    ERROR("Unknown pixel format: %s\n", arg);
+                }
+            }
         } else if (!av_strcasecmp(cmd, "VideoGopSize")) {
             get_arg(arg, sizeof(arg), &p);
             if (stream)