Flush SDP description

git-svn-id: file:///var/local/repositories/ffmpeg/trunk@15826 9553f0bf-9b14-0410-a0b8-cfaf0461ba5b

ffmpeg.c

@@ -1488,6 +1488,7 @@ static void print_sdp(AVFormatContext **avc, int n)
 
     avf_sdp_create(avc, n, sdp, sizeof(sdp));
     printf("SDP:\n%s\n", sdp);
+    fflush(stdout);
 }
 
 static int stream_index_from_inputs(AVFormatContext **input_files,