Call av_find_stream_info() immediately after opening an input file.

Needed to avoid reading the same TS two times at the beginning of the
file (whic resulted in an "error, non monotone timestamps..." when
streaming RTP from a file)

Originally committed as revision 10148 to svn://svn.ffmpeg.org/ffmpeg/trunk

ffserver.c

@@ -1917,6 +1917,7 @@ static int open_input_stream(HTTPContext *c, const char *info)
         return -1;
     }
     c->fmt_in = s;
+    av_find_stream_info(c->fmt_in);
 
     /* open each parser */
     for(i=0;i<s->nb_streams;i++)